U.S. patent application number 11/971805 was filed with the patent office on 2008-09-04 for method and device for preparing and/or analyzing biochemical reaction carriers.
Invention is credited to Hans Lindner, Manfred Muller, Cord F. Stahler, Fritz Stahler, Peer F. Stahler.
Application Number | 20080214412 11/971805 |
Document ID | / |
Family ID | 27512654 |
Filed Date | 2008-09-04 |
United States Patent
Application |
20080214412 |
Kind Code |
A1 |
Stahler; Cord F. ; et
al. |
September 4, 2008 |
METHOD AND DEVICE FOR PREPARING AND/OR ANALYZING BIOCHEMICAL
REACTION CARRIERS
Abstract
The present invention relates to arrays of biochemical and/or
biofunctional elements such as nucleic acids (oligonucleotides, for
example) or other biomolecules on a carrier surface and methods of
producing such arrays using photoactivation of predetermined areas
for synthesis using an illumination matrix that is
computer-controlled to generate an exposure pattern. This exposure
pattern can be adjusted and monitored by computer using a light
sensor matrix, for example a CCD matrix, to allow precise,
controlled illumination of specific regions and therefore
attachment of array building blocks to those specific regions. The
methods and compositions of the invention permit spatially resolved
photochemical synthesis of polymer probes on a carrier.
Inventors: |
Stahler; Cord F.; (Weinheim,
DE) ; Stahler; Peer F.; (Mannheim, DE) ;
Muller; Manfred; (Munchen, DE) ; Stahler; Fritz;
(Weinheim, DE) ; Lindner; Hans; (Stuttgart,
DE) |
Correspondence
Address: |
ARENT FOX KINTNER PLOTKIN & KAHN, PLLC
Suite 600, 1050 Connecticut Avenue, N.W.
Washington
DC
20036-5339
US
|
Family ID: |
27512654 |
Appl. No.: |
11/971805 |
Filed: |
January 9, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09763607 |
Apr 19, 2001 |
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PCT/EP99/06316 |
Aug 27, 1999 |
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11971805 |
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Current U.S.
Class: |
506/30 |
Current CPC
Class: |
B01J 2219/00441
20130101; B01J 2219/00436 20130101; B01J 2219/00711 20130101; B01J
2219/00689 20130101; C40B 40/06 20130101; B01J 2219/0059 20130101;
B01J 2219/00621 20130101; B01J 2219/00722 20130101; B01L 2300/0864
20130101; B01J 2219/00596 20130101; C12P 19/34 20130101; B01J
2219/00675 20130101; B01J 2219/00725 20130101; G01N 33/551
20130101; B01J 2219/00317 20130101; B01J 2219/00497 20130101; G01N
21/253 20130101; B01L 2300/069 20130101; C12N 15/10 20130101; B01L
2300/0816 20130101; B01J 2219/00608 20130101; B01J 2219/00637
20130101; B01J 2219/00603 20130101; B01J 2219/0061 20130101; Y10S
435/97 20130101; B01J 2219/00448 20130101; B01J 2219/00432
20130101; B01J 2219/00702 20130101; B01J 2219/00659 20130101; B01L
3/5085 20130101; C40B 50/14 20130101; B01J 2219/00479 20130101;
B01J 2219/00529 20130101; B01L 2300/0654 20130101; Y10S 435/973
20130101; B01J 2219/00585 20130101; B01J 2219/00439 20130101; B82Y
30/00 20130101; B01J 19/0046 20130101; C40B 40/10 20130101; B01J
2219/00605 20130101; B01J 2219/00612 20130101; B01J 2219/00511
20130101; B01J 19/0093 20130101; B01J 2219/00648 20130101; B01J
2219/00704 20130101; G03F 7/70216 20130101; B01L 3/502715 20130101;
G01N 21/6454 20130101 |
Class at
Publication: |
506/30 |
International
Class: |
C40B 50/14 20060101
C40B050/14 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 28, 1998 |
DE |
198 39 254.0 |
Aug 28, 1998 |
DE |
198 39 255.9 |
Aug 28, 1998 |
DE |
198 39 256.7 |
Feb 19, 1999 |
DE |
199 07 080.6 |
May 27, 1999 |
DE |
199 24 327.1 |
Claims
1-72. (canceled)
73. A method for synthesizing polymers, comprising synthesizing a
multiplicity of oligomeric building blocks on a carrier in parallel
steps, removing said oligomeric building blocks from said carrier
and bringing said oligomeric building blocks into contact with each
other to synthesize the polymers.
74. The method of claim 73, wherein said polymers are
double-stranded nucleic acid polymers of at least 300 bp.
75. The method of claim 74, wherein said polymers are
double-stranded nucleic acid polymers of at least 1000 bp.
76. The method of claim 74, wherein said polymers are nucleic acid
polymers selected from the group consisting of genes, gene
clusters, chromosomes, viral genomes, bacterial genomes and
sections thereof.
77. The method of claim 74, wherein said oligomeric building blocks
are from 5 to 150 monomeric units in length.
78. The method of claim 74, wherein said oligomeric building blocks
are from 5 to 30 monomeric units in length.
79. The method of claim 73, wherein a first portion of said
oligomeric nucleic acid building blocks are partially complementary
to a second portion of said oligomeric nucleic acid building blocks
and wherein, in successive steps, said first and second portions of
oligomeric building blocks are removed from the carrier and brought
into contact with each other under hybridization conditions.
80. A method for preparing a carrier coated with biologically or
chemically functional materials, which comprises: (a) providing a
carrier having a surface with at least one predetermined area and
which has photoactivatable groups thereon; (b) activating said
photoactivatable groups on said at least one predetermined area of
the carrier surface by location-specific exposure of the carrier
using an illumination matrix which can be controlled to generate an
optionally adjustable exposure pattern; (c) binding of biologically
or chemically functional materials or building blocks for such
materials on at least one of the predetermined areas in a
location-specific manner; (d) optionally repeating (b) and (c) on
the same predetermined area, at least one different predetermined
area or both; and (e) at least partially removing said biologically
or chemically functional materials on said carrier.
81. The method of claim 80, wherein said biologically or chemically
functional materials are polymers selected from the group
consisting of nucleic acids, nucleic acid analogs and proteins.
82. The method of claim 81, further comprising using said
biologically or chemically functional materials as building blocks
for further synthesis of polymers.
83. The method of claim 82, wherein said polymers are nucleic acid
polymers.
84. A method for preparing a carrier coated with biologically or
chemically functional materials, which comprises: (a) providing a
carrier having a surface with at least one predetermined area and
which has photoactivatable groups thereon; (b) activating said
photoactivatable groups on said at least one predetermined area of
the carrier surface by location-specific exposure of the carrier
using an illumination matrix which can be controlled to generate an
optionally adjustable exposure pattern; (c) binding of biologically
or chemically functional materials that are selected from the group
consisting of nucleic acids, nucleic acid analogs, both nucleic
acids and nucleic acid analogs and building blocks for such
materials, on at least one of the predetermined areas in a
location-specific manner; (d) optionally repeating (b) and (c) on
the same predetermined area, at least one different predetermined
area or both; (e) at least partially removing said biologically or
chemically functional materials on different areas of said carrier
in successive steps; and (f) using said biologically or chemically
functional materials as building blocks for further synthesis of
polymers.
85. The method of claim 84, wherein said polymers are nucleic acid
polymers.
86. The method of claim 80, comprising generating said exposure
pattern using electromagnetic radiation selected from the group
consisting of IR, visible, UV, X-ray or any combination
thereof.
87. The method of claim 80, comprising exposing said carrier to
radiation that is selected from the group consisting of pulsating,
coherent, monochromatic, parallel radiation and any combination
thereof, and wherein said radiation optionally is focused in
different planes.
88. The method of claim 80, wherein said carrier has more than one
predetermined area.
89. The method of claim 88, wherein more than one different
predetermined areas are exposed parallel.
90. The method of claim 80, wherein said illumination matrix is a
reflection matrix, wherein said reflection matrix optionally has a
mirror arrangement deformable in a controlled way.
91. The method of claim 90, wherein said reflection matrix is
selected from a light modulator with viscoelastic control layers
and a light modulator with micromechanical mirror arrays.
92. The method of claim 80, wherein said illumination matrix is a
matrix arrangement that comprises light sources or individually
controllable areas of one light source.
93. The method of claim 92, wherein said illumination matrix is
prepared on a chip.
94. The method of claim 92, wherein said illumination matrix is
selected from the group consisting of a laser array, a diode array
and both a laser array and a diode array.
95. The method of claim 80, wherein said carrier is optically
transparent.
96. The method of claim 80, wherein said carrier has a surface
consisting of semiconducting materials.
97. The method of claim 96, wherein said semiconducting materials
are selected from the group consisting of silicon, germanium
aresenide, gallium arsenide, glass, quartz glass, plastics and a
combination thereof.
98. The method of claim 80, wherein said predetermined area
comprises from 1 .mu.m.sup.2 to 1 cm.sup.2.
99. The method of claim 98, wherein said predetermined area
comprises from 100 .mu.m.sup.2 to 1 mm.sup.2.
100. The method of claim 80, wherein said predetermined area is
surrounded by nonactivated or/and nonactivatable areas.
101. The method of claim 100, wherein said illumination matrix
inherently generates an exposure pattern that illuminates said
predetermined areas.
102. The method of claim 80, wherein said biologically or
chemically functional materials are selected from the group
consisting of biological substances and materials that react with
biological substances.
103. The method of claim 80, wherein said biologically or
chemically functional materials are selected from the group
consisting of nucleic acids, nucleotides, oligonucleotides, nucleic
acid analogs, PNA, peptides, proteins, amino acids, saccharides,
cells, subcellular preparations, cell organelles, cell membranes,
viral particles, cell aggregates, allergens, pathogens,
pharmacological active substances and diagnostic reagents.
104. The method of claim 80, comprising synthesizing said
biologically or chemically functional materials on the carrier in
two or more stages from monomeric or/and oligomeric building
blocks.
105. The method of claim 80, comprising generating on the carrier a
substance library comprising a multiplicity of different
biologically or chemically functional materials.
106. The method of claim 80, wherein activating said
photoactivatable groups comprises cleaving a protective group off
the carrier itself or off materials or building blocks thereof
which are bound on said carrier.
107. The method of claim 80, wherein said exposure of the carrier
by said illumination matrix takes place at a rate of from 1/10000
to 1000 light patterns per second.
108. The method of claim 80, wherein said exposure of the carrier
by said illumination matrix takes place at a rate of from 1/10 to
100 light patterns per second.
109. The method of claim 80, further comprising monitoring said
exposure of the carrier, and optionally controlling said exposure
of the carrier, using a sensor matrix.
110. The method of claim 109, wherein said sensor matrix is a CCD
matrix.
111. The method of claim 110, wherein said illumination matrix,
carrier and sensor matrix form a transmitted-light arrangement.
112. The method of claim 110, wherein said illumination matrix,
carrier and sensor matrix form a reflected-light arrangement.
113. The method of claim 110, further comprising precalibrating
said carrier using said illumination matrix and said sensor matrix.
Description
[0001] The invention relates to the use of an illumination matrix
which can be controlled to generate an optionally adjustable
exposure pattern, in particular a programmable light source matrix,
in the field of biotechnology in general and for preparing,
manipulating and analyzing opto-fluidic reaction carriers in
particular.
[0002] Miniaturizing and at the same time functionally integrating
elements, components and whole systems make novel applications
available in many technologies. Said applications extend from
sensor technology via microsystem technology (e.g. complex biochips
using semiconductor technology) to actuator technology (e.g. in the
form of micropumps). The industries extend from classical
mechanical engineering via automotive and aviation industries to
medical technology and the forward-looking biotechnology. In
medical technology, for example, new implants are developed and the
pharmaceutical industry advances new technologies for efficient
development of novel medicaments and diagnostic systems at enormous
cost. Owing to its great potential, biotechnology in particular
profits from said development.
[0003] Novel methods which make use of the changed peripheral
conditions are developed for economical production in the field of
microtechnology. The same is true for the inspection techniques
required for monitoring the miniaturized processes.
[0004] For basic research in the life sciences and for medical
diagnostics and some other disciplines, gathering biologically
relevant information (mostly in the form of genetic information) in
defined examination material is extraordinarily important. In this
context, the genetic information is present in the form of an
enormous variety of different nucleic acid sequences, the DNA
(deoxyribonucleic acid). Realization of said information leads, via
producing transcripts of DNA into RNA (ribonucleic acid), mostly to
the synthesis of proteins which for their part are commonly
involved in biochemical reactions.
[0005] A powerful system format for gathering said wealth of
information is the so-called biochip. Biochips in this connection
mean highly miniaturized, highly parallel assays. Detecting
particular nucleic acids and determining the sequence of the four
bases in the nucleotide chain (sequencing) produces valuable data
for research and applied medicine. In medicine, it was possible, to
a greatly increasing extent through in-vitro diagnostics (IVD), to
develop and provide to the doctor in charge equipment for
determining important patient parameters. For many diseases,
diagnosis at a sufficiently early stage would be impossible without
said equipment. Here, genetic analysis has been established as an
important new method (e.g. case diagnosis of infectious diseases
such as HIV or HBV, genetic predisposition for particular cancers
or other diseases, or in forensic science). Close interaction
between basic research and clinical research made it possible to
elucidate the molecular causes and (pathological) connections of
some diseases down to the level of genetic information. This
development, however, has only just started, and greatly
intensified efforts are necessary, particularly for the conversion
into therapy strategies. Overall, the genome sciences and nucleic
acid analysis connected therewith have made important contributions
both to the understanding of the molecular bases of life and to the
elucidation of very complex diseases and pathological processes.
Moreover, genetic analysis or analysis through genetic engineering
already now provides a broad spectrum of diagnostic methods.
[0006] Further development in medical care is hampered by the
explosion in costs related to correspondingly expensive methods.
Thus, determining genetic risk factors by sequencing at the moment
still costs several hundred to several thousand US dollars. It is
necessary here not only to demand implementation of possible
diagnostic and therapeutic benefits, but also to advance
integration into a workable and affordable health-care system.
[0007] Likewise, applying appropriate technologies in research can
take place on a large scale and also at universities only if the
costs related thereto are reduced. Here, a change in paradigms of
research in life sciences begins to emerge:
[0008] The bottleneck of deciphering primary genetic information
(sequence of bases in the genome) and detecting the state of
genetic activity (genes transcribed into messenger RNA) of cells
and tissues is removed by the availability of sufficiently cheap,
powerful and flexible systems. It is then possible to concentrate
work on the (very complex) task of analyzing and combining the
relevant data. This should result in new levels of knowledge for
biology and subsequently in novel biomedical therapies and
diagnostic possibilities.
[0009] The biochips already mentioned before are miniaturized
hybrid functional elements with biological and technical
components, for example biomolecules which are immobilized on the
surface (outer surface or/and inner surface) of a carrier and which
may serve as specific interaction partners, and a matrix, for
example silicon matrix. Frequently, the structure of said
functional elements has rows and columns; this is known as a chip
array. Since thousands of biological or biochemical functional
elements may be arranged on such a chip, microtechnical methods are
usually needed to prepare said elements.
[0010] Essentially, two principles are used as methods for
preparing said arrays: application of finished probes or functional
elements to the reaction carrier, which is the predominantly used
method at the moment, or in-situ synthesis of the probes on the
carrier. The devices used for both principles are so-called
microfluidic spotters. In-situ synthesis may also use
photolithographic methods.
[0011] Possible biological and biochemical functional elements are
in particular: DNA, RNA, PNA, (in nucleic acids and chemical
derivatives thereof, for example, single strands, triplex
structures or combinations thereof may be present), saccharides,
peptides, proteins (e.g. antibodies, antigens, receptors),
derivatives of combinatorial chemistry (e.g. organic molecules),
cell components (e.g. organelles), cells, multicellular organisms,
and cell aggregates.
[0012] A multiplicity of photolithographic systems for
exposure-dependent generation of fine and very fine structures
using light of different wavelength (energy) of down to below 200
nm are commercially available for applications in semiconductor
technology. The finer the structures to be generated, the shorter
the wavelength used has to be. Thus, structures in the sub-.mu.m
range which are already in the range of visible-light wavelengths
(400-800 nm) can only be generated using high energy radiation of
distinctly shorter wavelength. Photolithographic systems consist in
principle of a lamp as energy or light source and a
photolithographic mask which has transparent and nontransparent
areas and thus generates an exposure pattern in the
transmitted-light course of ray. Optical elements reproduce said
exposure pattern on the object to be exposed (e.g. reduced by a
factor of 100). A line on the mask is thereby reduced in width from
0.1 mm to 10 .mu.m. Preparing a microstructure in or on a silicon
wafer commonly requires 10 to 30 exposure steps. The systems are
geared to said number and facilitate automatic mask switching by
means of magazines and operating tools.
[0013] Thus, an almost macroscopic structure of the mask results in
a microstructured image on the object to be exposed, for example
the silicon wafer. To generate a photolithographic mask,
photolithographic systems are likewise employed again which, of
course, need only a correspondingly lower resolution and also,
depending on the preparation method, only a correspondingly smaller
energy input. This is a cyclic process which has been very far
advanced and perfected due to the large market volume of the
semiconductor industry.
[0014] GeSim already uses for the production of photolithographic
masks LCD photo plotters from Mivatec. This is possible, since the
mask structures, with respect to structure size and required
wavelength, allow exposure in the visible-light range. This makes a
relatively fast and relatively flexible production of masks
possible. This is sufficient in semiconductor technology owing to
the limited number of masks required, since only a functional test
shows the success of the microstructuring and thus there is usually
always enough time for producing new or improved masks. Overall
however, producing the masks is expensive, time-consuming and not
very flexible.
[0015] Using photolithography for the light-induced in-situ
synthesis of DNA (synthesis directly on the biochip), Affymax
Institute and Affymetrix already use commercial exposure systems
for preparing high-density DNA microarrays (references: U.S. Pat.
No. 5,744,305, U.S. Pat. No. 5,527,681, U.S. Pat. No. 5,143,854,
U.S. Pat. No. 5,593,839, U.S. Pat. No. 5,405,783). The wavelength
employed is restricted to 300-400 nm. Each change in the exposure
pattern requires a mask change. This is extremely restricting since
preparing, for example, a DNA array with oligonucleotides of 25
building blocks in length (25-mers) per slot requires approx. 100
individual exposure cycles.
[0016] In general, the reaction carriers have a 2D base area for
the coating with biologically or biochemically functional
materials. The base areas may also be formed, for example, by walls
of one or more capillaries or by channels. An extension of the
geometry is a 3D structure in which analyzing and, where
appropriate, also manipulating or controlling the reactions take
place in a 2D arrangement.
[0017] Especially in the USA, enormous resources are used to
advance the development of miniaturized biochips.
[0018] Regarding the prior art, the following publications are
referred to, for example: [0019] 1. Nature Genetics, Vol. 21,
supplement (complete), January 1999 (BioChips) [0020] 2. Nature
Biotechnology, Vol. 16, pp. 981-983, October 1998 (BioChips) [0021]
3. Trends in Biotechnology, Vol. 16, pp. 301-306, July 1988
(BioChips).
[0022] Important application fields for miniaturized, parallel
assays and thus for applying the present invention are:
molecular diagnostics (including in-vitro diagnostics, clinical
diagnostics, genetic diagnostics)/development of pharmaceuticals
(substance development, testing, screening etc.)/biological basic
research (i.a. genomics, transcriptomics, proteomics,
physiomics)/-molecular interactions/analysis and screening of
pathogens (viroids, prions, viruses, prokaryotes,
eukaryotes)/oncology/environmental monitoring/food
analysis/forensic science/screening of medical products (i.a. blood
products)/detection, analysis and screening of transgenics (plants,
animals, bacteria, viruses, breeding, outdoor trials)/cytology
(i.a. cell assays)/histology/all types of nucleic acid analyses
(i.a. sequence analysis, mapping, expression
profiles)/SNPs/pharmacogenomics/functional genomics.
[0023] The object of the invention is to provide a method and a
device which facilitate relatively flexible and relatively fast
preparation and relatively efficient analysis of miniaturized
highly parallel reaction carriers.
[0024] Method and device should in addition facilitate integration
of preparation and analysis into one apparatus. Furthermore, it is
intended to create a basis for completely automating all processes
in preparation and analysis.
[0025] The method of the invention for preparing a reaction carrier
coated with biologically or biochemically functional materials
comprises the following steps. [0026] (a) providing a carrier
having a surface which has photoactivatable groups, [0027] (b)
activating the photoactivatable groups on at least one
predetermined area of the carrier surface by location-specific
exposure of the carrier using an illumination matrix which can be
controlled to generate an optionally adjustable exposure pattern,
[0028] (c) location-specific binding of biologically or chemically
functional materials or building blocks for such materials on at
least one of the predetermined areas and [0029] (d) where
appropriate, repeating the activation and binding steps on the same
or/and different predetermined areas.
[0030] The carrier is a solid phase which can be or is equipped
with biochemical or biological materials or receptors or building
blocks thereof. The carrier may have a planar surface or a surface
provided with grooves, for example channels. The channels are
preferably microchannels of, for example, from 10-1000 .mu.m in
cross section. The channels may be--depending on the surface
properties--capillary channels but also channels without capillary
action (e.g. owing to Teflon coating). The carrier is at least
partially optically transparent in the area of the reaction areas
to be equipped.
[0031] The use of an illumination matrix which can be controlled to
generate an optionally adjustable exposure pattern, facilitates
great flexibility in the preparation or/and manipulation or/and
analysis of opto-fluidic reaction carriers and, in particular,
faster preparation of reaction carriers than previously possible.
In contrast to generating correspondingly fine-resolution exposure
patterns in a photolithography machine by means of invariant
individual masks which have to be changed when changing the
exposure pattern, using a controllable illumination matrix can in
principle generate and alter any possible exposure pattern by
simply controlling the illumination matrix from a control computer.
Thus, in one production process it is in principle possible to
generate and analyze in one day hundreds to thousands of different
reaction carriers having a multiplicity of individual reaction
areas, something which has been impossible up until now.
[0032] The predetermined reaction areas for which a
location-specific exposure of the carrier is to be carried out are
selected for an actual application preferably automatically by a
program which facilitates controlling and assigning the reaction
areas to one or more reaction carriers according to the criteria
synthesis efficiency, optimal synthesis conditions, for example
temperature etc., optimal analysis conditions, for example
hybridization temperature with respect to neighboring areas. After
preparing the carrier, it may be provided for, where appropriate,
to change the carrier and to continue the process from step (a)
onward. In this context, step (c) may include the location-specific
binding of biologically or chemically functional materials or
building blocks for such materials in the same way as in the
preceding cycle or else taking into account the information from a
preceding synthesis cycle.
[0033] Programmability and electronic controllability of the
illumination matrix remove the exchange and also generation of the
mask units as were required for the photolithographic methods.
Generating the exposure patterns thus is no longer connected with
expenses for preparing, exchanging, positioning, storing and
optimizing exposure masks. This makes in particular the in-situ
synthesis of reaction carriers (e.g. DNA microarrays) accessible to
wide use. According to a preferred embodiment of the invention, an
illumination matrix is used which is able to illuminate with a
resolution of at least 500 points per cm.sup.2.
[0034] The illumination matrix and the assigned light source serve
in principle to provide the desired exposure pattern for
controlling/exciting photochemical processes or, where appropriate,
for analyzing a reaction carrier matrix. According to a variation,
it is possible to optionally modulate the light intensity and/or
wavelength of each luminous spot of the illumination matrix or of
the exposure pattern on the reaction carrier.
[0035] The illumination matrix used is preferably a controllable
reflection matrix which reflects light location-selectively,
according to its control, in a particular direction (here in the
direction of the reaction carrier). Such reflecting surface light
modulators having controlled deformable mirror arrangements for
generating light patterns can be in particular light modulators
having viscoelastic control layers or light modulators having
micromechanical mirror arrays. Regarding the technology of such
light modulators having viscoelastic control layers and light
modulators having micromechanical mirror arrays, relevant data
sheets of the Fraunhofer Institute for Microelectronic Circuits and
Systems are referred to and are attached to this application. The
advantage of such controllable reflection matrices is in particular
that they are available for a wide spectral range from UV to IR
light, for example in a wavelength range from 200-2000 nm. The
newest developments of controllable reflection matrices in 40V-CMOS
technology are advantageous in particular for transmitting
high-energy radiation in the UV range and also in general at high
energy densities per area. Due to the working voltage of 40 V, the
matrices are correspondingly insensitive. A further advantage is
that a reflection matrix of this type facilitates an exposure
parallel in time of all sites to be exposed in the exposure pattern
at appropriate illumination using a light field extending across
the matrix area. This possibility of parallel exposure of a
reaction carrier has consequences for the length of the preparation
(for in-situ syntheses), for the possibilities of online control
and evaluation (no artefacts due to time gaps between points of
measurement etc.) and for possible manipulations, for example in
the case of cell arrays or other biological components of a
reaction carrier (for example in the case of retina preparations or
light-dependent neuronal activity).
[0036] As long as parallel exposure is not crucial, it is possible,
instead of uniform illumination of the illumination matrix to carry
out screening or scanning of the illumination matrix using a
bundled beam, for example a laser beam, in order to generate the
desired light pattern on or in the reaction carrier, according to
the control of the illumination matrix. It is thus possible to
utilize a wide variety of light sources, for example also light
sources whose emission spectrum or emission wavelength can be
optionally altered, e.g. an N.sub.2 laser, so that, for example, a
plurality of signal-generating fluorescent substances on or in the
reaction carrier can be excited using different wavelengths (this
is a kind of 2D spectroscopy).
[0037] Another class of possible illumination matrices for the use
according to the present invention is represented by light source
arrays, i.e. matrix-like arrangements of very small light sources
which can be controlled individually. These can be, for example,
microlaser arrays, microdiode arrays or the like. UV-light emitting
diodes are available now whose emission wavelength is 370 nm. Such
UV-light emitting diodes are sold under the type designations NSHU
590 and NSHU 550 by Roithner Lasertechnik, A-1040 Vienna,
Fleischmanngasse 9. The corresponding UV-light emitting diode
technology can be used for preparing a diode array, in particular
microdiode array.
[0038] Therefore, the individually controllable spots of such a
light source array (light source matrix) correspond to the
individual illumination spots on the reaction carrier in the
individual reaction areas, it being possible for the generated
exposure pattern to be reduced in size, if necessary, with the aid
of suitable optical components.
[0039] Such a (self-luminous) light source matrix is different from
illumination matrices working as "light valves" such as, for
example, LCDs and those working as light reflectors such as, for
example, controllable micro-mirrors. A technical solution for a
light source array can be structures based on gallium nitride (GaN)
in a two-dimensional arrangement. GaN is known as a UV emitter, for
example from the preparation of commercially available UV LEDs. A
matrix having many independently controllable elements is built
from said structures through suitable wiring. Furthermore, a
correspondingly built microlaser array is conceivable in which, for
example, GaN can be used as laser-active medium.
[0040] Such a device may consist of, for example, a matrix of
emitting semiconductor elements emitting light of wavelength
<400 nm, as is done for example by GaN light emitting diodes. As
mentioned, a possible illumination matrix is also a correspondingly
built microlaser array. The size of a light emitting element may be
in a range between 500.times.500 .mu.m and 50.times.50 .mu.m. Each
matrix element can be separately controlled. For an exposure as the
starting point of a biochemical reaction, at least one light
emitting diode emits photons within a wavelength range below 400
nm. Since the device has been designed preferably as a unit for
initiating spatially separated photochemical reactions in a
reaction carrier, the illumination matrix needs to be less than 75%
occupied with light emitting elements. The size of the light source
matrix is larger than or equal to the optical image on the reaction
carrier. Minimizing the image may be required and is preferably
achieved by lightwave conduction in a glass fiber bundle (fused
fiber optic taper), optionally also by suitable lens systems. Fused
fiber optic tapers are known to be employed in nightvision devices,
for example.
[0041] The arrangement pattern of the UV-light emitting diodes
preferably corresponds to the pattern of the synthesis positions in
the reaction carrier.
[0042] The structure of the illumination component (self-luminous
light source matrix) thus consists of a matrix on which UV-light
emitting diodes or microdiode lasers are arranged in rows and
columns. The individual light source elements of said matrix are
controlled to generate a specific exposure pattern which
corresponds to the pattern of the synthesis positions in the
reaction carrier.
[0043] The individual light source elements are controlled, for
example, row- and columnwise which causes pulsating of the
individual light emitting diodes or laser elements, i.e. a variable
light intensity is emitted. A similar method of control can be
found, for example, in LCD illumination matrices. Alternatively,
the individual light emitting diodes of the matrix can be
statically controlled by flip-flops or DRAMs and also by other
suitable switches.
[0044] The light source array may be immediately followed by a
matrix made from optical microelements (or else a mechanical shadow
mask to suppress light scattering). This component may consist for
its part of one of several interconnected layers of microscopic
optical elements (e.g. microlenses) and is expediently mounted
directly on the light source matrix.
[0045] In one embodiment, the microoptical component is immediately
followed by a fused fiber optic taper which serves to minimize the
illumination pattern in a 1:1, 2:1, . . . 25:1 ratio
(entrance:exit) or possible intermediate values. Here, the
individual fibers of the fused fiber optic taper may be isolated
from one another by a black sheathing.
[0046] Between the individual components of the device there may be
a fluidic optical medium. The exposure pattern generated may for
its part be coupled into the reaction carrier via a fused fiber
optic taper which is mounted directly on the surface of the planar
reaction carrier.
[0047] The possible structure of the reaction carrier and the
arrangement of a light sensor matrix (multichannel detector matrix)
which is preferably provided in the form of a CCD chip is explained
in the following.
[0048] The reaction carrier is arranged on the light-emitting side
of the light source matrix. The reaction carrier is optically
transparent at least on the side facing the illumination matrix.
This makes it possible to generate a spatially resolved exposure
pattern in this reaction carrier, which can be an opto-fluidic
microprocessor, for example. In this way, it is possible to control
in a spatially resolved manner immobilizing or synthesizing polymer
probes in the reaction carrier by using suitable photochemistry
within the individual reaction areas.
[0049] A device for implementing the method described can be built
in a very compact and space-saving way and may then carry out both
synthesis activation on the reaction carrier and thus doping the
reaction areas with the appropriate polymer probes, and signal
detection after adding sample material.
[0050] Between the reaction carrier and the relevant light sensor
matrix a spectral filter (bandpass or longpass) may be present
which facilitates spectral separation of the signal light from the
exciting light in the fluorimetric detection of the analytes bound
to the biochip (reaction carrier). Moreover, using a filter wheel
containing various optical filters allows simultaneous detection of
analytes of various sample materials which have been labeled by
different fluorophores with fluorescence maxima far apart in the
spectrum.
[0051] The operating modes of the light source matrix (illumination
matrix) and the relevant light sensor matrix (e.g. CCD array) can
be synchronized by either suitable hardware or software. If the
individual elements of the illumination matrix can be switched on a
nanosecond timescale without, for example, "afterglow", then
electronic synchronisation with a so-called gated CCD camera via an
external frequency generator is also possible. Since the
fluorescence lifetime of common fluorophores is usually a few
nanoseconds long, in this way separation in time of the exciting
light and the signal light is possible for the fluorimetric
detection of the analyte so that time-resolved spectroscopy can be
carried out.
[0052] Another class of illumination matrices which can be used
according to the invention is represented by matrix arrangements of
"light valves" or controllable transmitted-light modulators which
can be controlled location-selectively in order to let or not to
let light through. Said devices are electronic components in which
the light of a light source falls on a matrix of controllable
pixels. Each pixel can be modulated by the electronic control
signal with respect to its optical transparency. Thus a
controllable light valve matrix LVM is created. In order to fulfill
the function of the light valve, parts of the electronic components
(i.a. the actual electrodes) have to be transparent. The group of
light valves includes as its most prominent representative the
liquid crystal display LCD. Light valves based on LCD are very
common, as micro version i.a. in the viewfinder of digital
videocameras and in nightvision devices, and as macro version, for
example, in laptops or as display for personal computers.
Transmission in the dark state is still up to 10% of the amount of
light coming in from the back, though. LCDs are available for
transmitted light wavelengths of above 400 nm. For exposure in the
UV range, the contained crystals are badly suited, i.a. owing to
their intrinsic absorption (see i.a. Microsystem Technologies 1997,
42-47, Springer Verlag). For configuring LVMs in the UV range,
therefore, other substances are necessary as filling between the
transparent electrodes. Such alternative substances are known, for
example, from so-called suspended particle devices SPD (see i.a.
U.S. Pat. No. 5,728,251). These and other substances can be used
with the same electrode arrangement as LCDs, but it is also
possible to use other transparent components.
[0053] The method of the invention may provide for the carrier to
be exposed to pulsating, coherent, monochromatic, parallel
radiation or/and, where appropriate, to radiation which can be
focused in different planes.
[0054] The reaction carrier or biochip may have, for example, a
semiconductor surface, a glass surface or a plastic surface for
coating with biologically or biochemically functional materials,
which surface may be an outer surface or/and an inner surface of
the carrier, the latter, as long as the carrier is at least
partially hollowed out, for example has channels running through.
Preference is given to using a transparent carrier which
facilitates optical studies in transmitted light mode.
[0055] The predetermined activatable areas may include, for
example, an area of from 1 .mu.m.sup.2 to 1 cm.sup.2, in particular
100 .mu.m.sup.2 to 1 mm.sup.2. The predetermined activatable areas
may be surrounded by nonactivated or/and nonactivatable areas.
[0056] The illumination matrix may have a pattern inherent to the
predetermined activatable areas, for example with sites which cause
always shading or darkness in the exposure pattern.
[0057] The biologically or biochemically functional materials are
selected preferably from biological substances or from materials
reacting with biological substances, namely preferably from nucleic
acids and nucleic acid building blocks, in particular nucleotides
and oligonucleotides, nucleic acid analogs such as PNA and building
blocks thereof, peptides and proteins and building blocks thereof,
in particular amino acids, saccharides, cells, subcellular
preparations such as cell organelles or membrane preparations,
viral particles, cell aggregates, allergens, pathogens,
pharmacological active substances and diagnostic reagents.
[0058] The biologically or biochemically functional materials are
preferably synthesized on the carrier in two or more stages from
monomeric or/and oligomeric building blocks.
[0059] The great flexibility of the method according to the
invention facilitates generating an expansive substance library
having a multiplicity of different biologically or chemically
functional materials on the carrier.
[0060] The activation of predetermined areas comprises in
particular cleaving a protective group off the carrier itself or
off materials or building blocks thereof which are bound on said
carrier.
[0061] The illumination matrix facilitates a flexible control of
the time course of the exposure so that the exposure may take place
at a rate in the range of from, for example, 1/10000 to 1000, in
particular 1/10 to 100 light patterns per second.
[0062] According to a preferred variation of the method, exposure
of the carrier is monitored by a light sensor matrix, in particular
a CCD matrix, and, where appropriate, controlled taking into
account the information obtained by said monitoring. Preferably,
the sensor matrix is arranged opposite to and facing the
illumination matrix, with the carrier being positioned between
illumination matrix and sensor matrix in order to make
transmitted-light observation possible. Alternatively, the
illumination matrix, carrier and sensor matrix may also be grouped
in a reflected-light arrangement.
[0063] The sensor matrix may be used for carrying out automatic
recognition and/or, where appropriate, calibration of the
particular carrier used by means of an analysis unit connected
after the sensor matrix.
[0064] A further development of the invention may provide for
removing the materials synthesized on the carrier, in particular
polymers such as nucleic acids, nucleic acid analogs and proteins
in order to provide them for particular purposes. In this aspect,
it is possible to make use of the method practically as a
preparation method for biochemical materials. In this context, it
may be provided for to remove the materials in different areas in
successive steps and to use them as building blocks for further
synthesis of polymers, in particular nucleic acid polymers.
[0065] Further aspects of the invention are given in claims 25 to
40, in particular the use of an illumination matrix which can be
controlled to generate an optionally adjustable exposure pattern as
light source of a light-emission detector for detecting the optical
behavior of a 2- or 3-dimensional test area provided with
biologically or biochemically functional materials, the test area
being preferably prepared in the light-emission detector.
[0066] A further aspect of the invention should be pointed out,
according to which a controllable illumination matrix is used for
exposing in a spatially resolved manner reaction carriers with
cells/tissue sections, in order to carry out exposure-dependent
manipulations (light-sensitive processes such as photosynthesis,
manipulation of retina preparations, light-dependent neuronal
activity) or analyses (as 2D-FACS; cell-array, tissue-derived
cell-array).
[0067] The invention further relates to a light-emission detector
as claimed in any of claims 41-43.
[0068] In this context, the illumination matrix or light source
matrix is an illumination matrix which can be location-selectively
controlled with respect to its optical transparency, in particular
a light valve matrix, a reflection matrix or a self-luminous or
self-emitting illumination matrix.
[0069] According to an embodiment of the light-emission detector,
the illumination matrix is based on a light valve matrix (e.g. LCD
matrix). In combination with a suitable light source, the light
valve matrix makes the production of a highly parallel,
high-resolution and location-specific exciting light source and
inspection light source possible which, owing to its flexibility,
opens up a multiplicity of possible applications. Light valve
matrices are well advanced in their development due to their wide
use in the electronic consumer goods sector and are therefore
reliable, cheap and extremely small. As already illustrated, a
possible application of this type of illumination matrix is to
replace the relatively expensive photolithography (e.g. in the
photoactivated oligo synthesis when preparing DNA chips) at
relatively low resolutions, such as, for example, for simple Si
chips or DNA chips.
[0070] The light sensor matrix can preferably be a CCD image
recorder (CCD camera chip). If these two chips are arranged
opposite to each other, then an extremely compact, highly parallel
excitation, inspection and detection unit is obtained for an even
larger number of applications. The two-dimensional light-emission
detection unit develops its enormous potential in particular due to
the intelligent interaction of two-dimensional control and
two-dimensional readout. Here, the power of modern computers and
software systems provides enormous potential for application and
development, and both hardware and software can be based on the
available systems for utilizing the light valve matrix (e.g. LCD)
as man/machine interface. In applications using a combination of
light source and detector, the intensity sensitivity (e.g. 264 to
4096 or to several 100 000 levels for CMOS CCDs) and the color
(i.e. wavelength) distinction in the CCD chip (e.g. peak filters
for red, green and blue or other colors, depending on the filters
in front of the pixels) are suitable for two-dimensional
spectroscopy. An object or other test samples to be
studied/analyzed/excited or otherwise specifically illuminated with
light and synchronously screened for light emissions is introduced
onto or into the carrier between illumination matrix and light
sensor matrix. A kind of sandwich structure composed of
illumination matrix, carrier or test object and light sensor matrix
is created. The distance between the illumination matrix and the
test object and likewise between the test object and the light
sensor matrix chip should preferably be minimal in order to
minimize the deviation (scattering) of light from the relevant
pixel of the illumination matrix to the opposite pixel of the light
sensor matrix.
[0071] During the synthesis steps, the light-emission detector also
serves as a detector, for example, for movements of fluids and
allows integrated quality control or process control. This has a
positive effect on quality and use of resources and reduces the
reject rate. If no process monitoring during synthesis is needed
and detection is carried out in a separate system, it is also
possible to replace the light sensor matrix with a temperature
control unit, for example.
[0072] The arrangement of a highly parallel illumination matrix and
a highly parallel light sensor matrix creates a widely usable,
novel inspection unit which may also be denoted as a massive
parallel light barrier which, if necessary, additionally includes
the advantages of quantitative and qualitative excitation and
measurement. Another specific feature is the possible use of light
of different colors (different wavelengths). In the case of a light
valve matrix, it is possible, for example, to determine the
excitation wavelength fundamentally by specifically using the
appropriate background illumination of the light valve matrix.
[0073] Another strength of the light-emission detector is the
almost endless possibilities which result from combining specific
excitation with specific detection in conjunction with modern
supercomputers for control and signal analysis. Thereby a new
technology platform is created, especially for optical detection
methods. Tuning of individual luminous spots in combination with
CCD detection and suitable algorithms for the signal analysis ought
to make very small changes in individual points of measurement in a
light-emission detector possible. In DNA analysis, for example,
detecting a hybridization directly in a reaction area would be
conceivable.
[0074] In relation to image processing and to controlling the
system components of the light-emission detector, it is possible,
where appropriate, to make use of hardware and software tools.
Examples are graphic cards, video cards and the appropriate
software.
[0075] Compared to conventional photolithographic systems, the
light-emission detector provides the possibility of extreme
miniaturization with simultaneous functional integration when used
as synthesis and analysis system (ISA system), in particular when
using a light valve matrix, a reflection matrix, a diode array or a
laser array as illumination matrix and a CCD image converter as
light sensor matrix.
[0076] Particularly interesting applications of a light-emission
detector of the invention are discussed briefly in the following:
[0077] Preparation of an opto-fluidic reaction carrier, in
particular according to a method as claimed in any of claims 1-35.
In this connection, the light-emission detector of the invention is
suitable in particular also for preparing a carrier for analyte
determination methods which contains a multiplicity of channels, in
particular capillary channels, in which a multiplicity of different
receptors has been immobilized or is to be immobilized. Such a
carrier is described, for example, in DE 198 39 256.7 (see priority
document DE 198 39 256.7 for the present application). To prepare
such a carrier, a carrier body having a multiplicity of channels is
provided. Liquid which contains receptors or receptor building
blocks is passed through the channels of the carrier body and
receptors or receptor building blocks are immobilized in a
location- or/and time-specific manner at in each case predetermined
positions in the channels. Immobilizing can take place in the
light-emission detector of the invention through exposure by means
of the illumination matrix. A receptor can be synthesized on the
carrier body by a plurality of successive immobilization steps of
receptor building blocks. [0078] As mentioned, photoactivation
takes place at each step directly through the illumination matrix.
In the case of using an LCD as illumination matrix, the wavelength
of about 365 nm required for this process cannot be reached, unless
the LCD has been designed as SPD. [0079] It is conceivable that the
user generates his highly parallel reaction carriers himself and
uses them directly. He simply downloads the required data (DNA
sequences) from a CD-ROM or from the Internet and generates in the
light-emission detector (structure analogous to an external disk or
CD-ROM drive) his individual DNA chip, moistens it subsequently
with the sample and reads out the signals. [0080] If, for example,
every second pixel in this arrangement is used for photoactivation,
then the pixels in between which are located within a capillary
(microchannel in a reaction carrier) of the at least in some areas
essentially transparent carrier body can be used for permanent
process control. Thus, for example, the inflow of an air bubble
between two fluids in a capillary can be followed individually and
dynamically. Coloring the carrier fluids for G, A, C and T is also
conceivable so that it would become possible to check the presence
of the correct oligonucleotides and a color change could signal a
contamination. During the subsequent detection, in turn a
location-specific and, if necessary, even color-specific light
excitation could take place. This leads to entirely new
possibilities for detection methods which are at present not yet
available. [0081] By means of the light-emission detector it is
further possible to monitor flow processes in the capillaries in a
glass or plastic chip as carrier body both during production, that
is to say oligo synthesis, and during analysis. For this it is
possible, for example, to use air bubbles for cleaning between two
fluids in the capillaries, or coloring of the individual fluids.
[0082] The illumination matrix may serve for the light-induced
removal of protective groups during the synthesis of DNA oligos on
the chip (carrier body) with, for example, an exposure wavelength
of 365 nm. The required power is 14 mW per cm.sup.2, for example.
Eventually, further developments in chemical synthesis are also
possible which utilize different wavelengths, for example. [0083]
The light-emission detector of the invention may likewise carry out
detection of the test reaction for analyte determination methods in
the carrier. If detection is carried out by fluorescent labels, the
background illumination, where appropriate, would have to be
changed for this purpose (automatically possible). Where
appropriate, novel detection methods are also employed which only
the extremely flexible individual illumination and detection of the
individual points of measurement make possible. [0084] In a
preferred embodiment, the detection method for determining an
analyte using a reaction carrier coated with biologically or
biochemically functional materials includes the following steps:
[0085] (a) providing a reaction carrier having a multiplicity of
different location-specifically bound or chemically functional
materials, [0086] (b) adding a, where appropriate prepared, sample
containing the analyte(s) to be determined, contacting the sample
with the reaction carrier under conditions in which the analyte(s)
to be determined bind(s) to the carrier-bound materials (receptors)
and, where appropriate, subsequently washing the reaction carrier,
and [0087] (d) optically analyzing the reaction areas in backlight
or transmitted light by means of illumination matrix and sensor
matrix.
[0088] The analyte determination steps (a) to (c) may be integrated
into the synthesis process so that the analysis is carried out
immediately after finishing the synthesis. This facilitates using
the results from the analysis of a previous synthesis cycle for
selecting the necessary carrier-bound materials for the reaction
areas in the subsequent reaction carrier. It is then possible to
continue the method with step (a), since the result from the
analysis may require new selection of the materials bound in the
reaction areas. [0089] Another possible application for a
light-emission detector of the invention relates to the
incorporation into a method for determining a multiplicity of
analytes in a sample as is described in the German patent
application 198 39 255.9 (see priority document DE 198 39 255.9 for
the present application). Said method for determining a
multiplicity of analytes in a sample includes the steps: [0090] (a)
contacting the sample with [0091] (i) a multiplicity of
microparticle types, each type being suitable for detecting
particular analytes and having a particular coding which is
optically distinguishable from other types, and [0092] (ii) a
multiplicity of soluble, analyte-specific detection reagents which
carry a signal-emitting group or can bind to a signal-emitting
group, [0093] (b) subsequently applying the microparticles onto a
carrier and [0094] (c) determining the analytes by optical
detection of the coding and the amount present or/and the absence
of the signal-emitting groups on at least one type of individual
microparticles on the carrier. [0095] Suitable samples are in
particular biological samples. The microparticles may be organic
particles such as organic polymer lattices or inorganic particles
such as magnetic particles, glass particles etc. [0096] Each type
of the preferably optically transparent microparticles has on its
surface at least one immobilized, different, analyte-specific
receptor. The microparticles are preferably color-coded. For each
analyte to be determined, at least one soluble, analyte-specific
detection reagent is used. [0097] After applying the microparticles
onto the carrier and inserting the carrier between the illumination
matrix and the light sensor matrix, it is possible to determine a
statistical or dynamic arrangement of the microparticles on the
carrier by means of the light-emission detector, specifically by
image detection by means of the light sensor matrix. [0098] The
microparticles which are also called beads or smart beads represent
in their entirety a multiplicity of points of measurement. The
light-emission detector facilitates not only localization and
assignment of the individual beads in their arrangement on the
carrier by means of the light sensor matrix, but moreover also a
likewise localized illumination. In this combination, the
light-emission detector is therefore particularly suitable for
localizing and identifying parts of the carrier, also called
fractal chip, and for delivering the necessary data using the
appropriate software in order to prepare the fractal chip with high
precision. The principle of this structure and the comprehensive
access through illumination and detection should keep the error
rate extremely low. [0099] The light-emission detector can monitor
the flow processes of the smart beads in a fractal chip during
analysis. [0100] Reading out the information from a smart bead
array should take place in the light-emission detector, with the
exciting light source, i.e. the illumination matrix, being located
directly above the smart bead array and the light source matrix
directly below the fractal chip with the smart bead array. This
most compact construction minimizes the light paths and thus also
the required light intensity as well as superposition effects of
neighboring smart beads. The use of complicated, bulky,
light-absorbing and expensive optics can be dispensed with, both on
the excitation and the detection sides. [0101] Another variation is
a vertical orientation of the chip so that gravitational forces can
also be utilized for loading and unloading the chip with the smart
beads. [0102] The sensor matrix can again be a CCD chip, for
example. If, on such a CCD area of 25.times.37 mm with
2000.times.3000 color pixels, microparticles (smart beads) of 60
.mu.m in diameter are arranged for direct detection, then at least
200,000 microparticles (smart beads) are obtained. Each
microparticle covers approx. 120 squared color pixels with edges of
5-10 .mu.m in length. This produces 30-40 color signals or 120
black and white signals per smart bead with a digital light
intensity grading of 256 to 4096 (depending on the CCD chip)
discrete brightness levels for each black and white pixel. Thus, in
any case, a sufficient amount of data is present for a statistical
verification of the signals. [0103] The limit of the maximum number
of synchronously detectable, differently color-coded smart beads is
determined by the possibility of specific codability (chemical
limit of reproducible color generation) of the smart beads and also
by the possibility of optical detection of the color differences
using a CCD chip. If the 256 intensity levels per color (RGB
minimum requirement) are divided into 10 levels, then
25.sup.3=15,625 possible colors are obtained which can be detected.
Extending the number of color classes using further color filters
can increase further the number of detectable colors. Using
quadruple color filters (e.g. RGB and magenta) in front of the
above-described CCD chip would make it possible to detect
theoretically 25.times.25.sup.3=390,625 colors, with only approx.
30 quadruple color pixels left, of course. Owing to great advances
in CCD technology, the listed numbers only describe the minimum
standard in this technique. New chips already have a color depth of
12 bits (4096) and the first prototypes already have 81 million
pixels over the same area. This results in a large growth potential
also for the described application of CCD chip technology, and the
parallel detection of 10.sup.6 individual smart beads is
technically feasible. [0104] According to a variation, it may be
provided for an optical gate to be provided between smart bead
array (fractal chip) and CCD camera chip. [0105] According to
another variation, it may be provided for optical elements, in
particular imaging elements to be present between the smart bead
array (fractal chip) and the CCD camera chip. [0106] Applying the
light-emission detector to high throughput screening (HTS)
equipment would make it possible to construct in parallel any
number of light-emission detector units or to integrate them into
one apparatus in a modular way. Providing the oligos and also the
washing liquid and the prepared sample is again a question of the
embodiments. Here, numerous possibilities are available, from
providing in the analysis apparatus to providing the exactly
required amount directly in the reaction carrier to which just the
sample, for example after PCR, is added. Integrating the sample
preparation into the carrier chip is also conceivable, of course.
In one variation, the fluids are driven into the appropriate
capillaries only by capillary forces. For the individual steps,
only the integrated valve has to be switched by a switching motor
in the apparatus (e.g. externally by a micromotor or a
piezoelectric drive, if the light-emission detector is to be
miniaturized accordingly). If the individual containers or cavities
in the chip were only closed with a foil or membrane or an
appropriate lid, it would be possible in the case of insufficient
capillary force to achieve a pumping function by applying pressure
from the top. [0107] One possible use of a light-emission detector
of the invention could be the monitoring of slow flow processes in
thin layer chromatography (TLC). Here, color labeling of the
migration for the detection may, where appropriate, be dispensed
with and a direct "in situ" control by the compact and
cost-effective light-emission detector may be carried out instead.
[0108] A light-emission detector of the invention may also be used
as inspection unit etc. in microsystem technology. [0109] Regarding
the use of the light-emission detector for analyte determination in
biochips, it should be furthermore noted, that from using CCD
detection a lens-less signal detection should be expected which can
distinguish at least three separate wavelength peaks (colors: red,
green, blue) and 64 intensity levels. [0110] Integrating the
differentially locatable exciting light source as illumination
matrix will allow a plurality of excitation wavelengths (at least
three, corresponding to the color scheme in monitors), so that
using different fluorescent labels is possible without problems.
[0111] Another possible application for a light-emission detector
of the invention is cytometry and the studying of other
sufficiently small biological objects. The light-emission detector
generally monitors a 2D matrix by localized light barriers, the
emission width and high sensitivity and wavelength-dependent
detection making the use of spectrometic principles possible.
[0112] A matrix of this type is therefore excellently suited for
studying particles which are located in a liquid medium between
"detector" and "analyzer". [0113] An interesting application is the
studying of whole cells as "particles". In contrast to a cytometry
carried out in a 1D capillary, parallel classification of the cells
according to their optically detectable parameters takes place in
this case. [0114] Determination according to size, optical
properties such as fluorescence (after appropriate labeling using
specific or nonspecific stains, for example antibody and lipophilic
stain, respectively) or movement, for example in the case of
macrophages, pathogenic or other single cell organisms or the like,
is conceivable. The studying of sufficiently small multicellular
organisms is possible too, for example a complete C. elegans
population under certain experimental conditions. [0115] Another
field of application for a light-emission detector of the invention
is provided by gel electrophoresis. In this case it is possible to
monitor and analyze online the gel electrophoretic separation of
biological test material, for example of DNA in agarose gels, by
means of a light-emission detector, if electrophoresis chamber and
light-emission detector are integrated accordingly. The user would
be able to follow the separation, for example, via the monitor.
[0116] This would facilitate the analysis at the earliest time of
the separation, which possibly results in an enormous time saving.
The whole equipment could probably be designed distinctly smaller
than is the case at the moment, owing to the sensitive and
high-resolution light-emission detector, since most gel
electrophoresis experiments are primarily evaluated by naked eye,
and only secondarily a small part of separations is analyzed under
a scanner. Said minimization results in improved cooling, which in
turn facilitates higher voltage and thus quicker separation. Thus,
further acceleration of the process is conceivable and overall
great time savings are possible (compared to capillary
electrophoresis, acceleration by a factor of 10 is quite realistic,
with reduced consumption of material and analyte). [0117] A
possible extension is the automatic removal of material from the
electrophoresis gel measured online, for example by a connected
mini-robot/computer-controlled apparatus.
[0118] Some aspects of the invention are illustrated in the
following, with respect to the figures.
[0119] FIGS. 1-5 depict diagrams of different exemplary embodiments
for devices for preparing/manipulating/studying a carrier (biochip)
coated with biologically or chemically functional materials.
[0120] FIG. 6 depicts a cross section of a part of a carrier with
integrated illumination matrix.
[0121] FIG. 7 depicts in a highly diagrammatic way an exemplary
embodiment of a light-emission detector of the invention.
[0122] FIGS. 8 to 11 depict diagrams of devices of the invention
which have self-luminous illumination matrices.
[0123] FIG. 1 depicts a first embodiment of an arrangement for
preparing a biochip or/and for manipulating or/and for studying
biologically or biochemically functional materials immobilized
thereon.
[0124] The arrangement according to FIG. 1 can be conceptually
divided into three groups of functional modules or system modules
2, 4, 6. The system module 2, also called below programmable light
source matrix, includes at least one light source 8, at least one
illumination matrix 10 which can be controlled to generate an
optionally adjustable exposure pattern, and a control computer 12
which may be, for example, a programmable single chip
microprocessor which is able to communicate, if required, with an
external computer via an appropriate interface and which serves to
control the illumination matrix 10 using an appropriate programme.
Alternatively, the illumination matrix can be controlled from an
external computer, for example personal computer. The system module
2 may further include optical elements 11, 14 which may be lenses,
apertures, masks or the like and which are arranged for possible
exchange where appropriate.
[0125] The second system module 4 is the exchangeable carrier or
biochip which is to be exposed by the programmable light source
matrix 2. The third system module 6 is a light detection unit which
preferably includes a matrix made of light sensors 16. The matrix
16 is preferably an in particular color-capable CCD sensor chip
which can be used for spectrally resolved and intensity-resolved,
location-selective measurements. Where appropriate, the system
module 6 may also contain optical elements 18 such as lenses,
apertures, masks or the like.
[0126] The light sensor matrix 16 is arranged opposite and facing
the illumination matrix 10, the carrier 4 being located in the
(transmitted) light path between the illumination matrix 10 and the
light sensor matrix 16.
[0127] In the case of the example according to FIG. 1, the
illumination matrix 10 is an electronically controllable optical
component whose transparency can be controlled with spatial
resolution according to the resolution of the matrix, i.e. the
arrangement and size of the matrix elements which form the matrix
and which can be specifically controlled; the transparency can be
switched preferably between two states, namely the essentially
opaque state and a state of maximum transparency for the light of
the light source 8. The illumination matrix 10 therefore can be
considered as an electronically adjustable mask in a transmitted
light arrangement. Depending on the control by the control computer
12, the illumination matrix 10 generates an exposure pattern which
is used for exposing the carrier 4 location-selectively. The
illumination matrix 10 used in the arrangement according to FIG. 1
is preferably a light valve matrix (LCD matrix with SPD filling).
It is in principle also possible to use other light valve
arrangements which can be controlled with spatial resolution, for
example microplates, microsliders, etc., in order to realize an
illumination matrix 10 of the kind depicted in FIG. 1.
[0128] The detection module 6 may be connected to the computer 12
or, where appropriate, to an external computer, for example
personal computer, to control said module and to process the
measurement information it provides.
[0129] The system modules 2 and 6 are preferably arranged on a
shared holder which is not shown in FIG. 1, and they can be, where
appropriate, adjusted relative to one another. The holder further
has a sliding guide or the like by means of which the exchangeable
carriers 4 can be introduced in each case into the position
according to FIG. 1 in a simple manner and can be removed again
from said position for removal of the appropriate carrier 4.
[0130] The arrangement according to FIG. 1 can be used in the
preferred manner to coat an appropriate carrier 4
location-selectively with biologically or biochemically functional
materials. For this purpose, a carrier 4 is used which has a
surface having photoactivatable groups. Examples of suitable
carriers are i.a. given in the German patent application 198 39
256.7. The programmable light source matrix 2 is used to generate
an exposure pattern on the carrier surface provided with
photoactivatable groups, in order to activate the photoactivatable
groups in predetermined areas which are exposed to the light of the
light source 8 in accordance with the exposure pattern. Via the
feed 20, appropriate reagents may be fed to the surface (in the
example to an inner surface of the carrier), which contain the
desired biologically or biochemically functional materials or
building blocks for such materials which are then able to bind to
the predetermined areas. 21 denotes a discharge tubing for the
reagents.
[0131] The biologically or biochemically functional materials or
building blocks may for their part be provided with
photoactivatable groups which can be activated by area in a
possible subsequent activation step in accordance with the chosen
exposure pattern, in order to bind in a further binding step
biologically or biochemically functional materials or building
blocks for such materials corresponding to the reagents employed.
Not listed above were possible washing steps to flush the reagents
used last, prior to the respective next exposure step. Depending on
the activation wavelength of the photoactivatable groups, the
exchangeable light source 8 may be a particular radiation source
emitting in the infrared range, in the visible range, in the
ultraviolet range or/and in the X-ray range.
[0132] Exposure, washing and binding steps can be repeated in a
specifically controlled manner in order to generate, for example, a
high-density microarray of biomolecules such as, for example, DNA,
RNA or PNA.
[0133] Applications of this type do not necessarily require the
light detection module 6; it is, however, possible to utilize said
module expediently for online quality control of the processes
which are light-dependent and take place in or on the carrier 4,
i.e., for example, for monitoring an in-situ synthesis of
biomolecules for preparing a microarray. The light sensor matrix 16
facilitates monitoring with spatial resolution the light-dependent
processes via optical signals. The light detection module 6 may
generally be used for graduating or calibrating the system prior to
a synthesis or analysis or other reactions or manipulations on or
in the carrier.
[0134] The light sensor matrix 16 may, where appropriate, also be
used for type recognition in which, for example, a carrier or chip
body assigned to particular applications is automatically detected
and the reactions and settings during subsequent processes are
automatically adjusted.
[0135] By using the optical elements 14, it is possible to focus
the two-dimensional exposure pattern, where appropriate, in one or
more particular planes in or on the reaction carrier. Shifting the
focusing plane during a process is also conceivable.
[0136] FIG. 2 depicts a diagram of a second embodiment of an
arrangement for preparing, studying and/or manipulating a reaction
carrier. Elements in FIGS. 2-6 which correspond in their function
to elements in FIG. 1 are marked with in each case corresponding
indicators so that in this respect the description of the first
exemplary embodiment can be referred to. In the embodiment
according to FIG. 2, the illumination matrix provided for is an
electronically controllable reflection matrix 10a. The
electronically controllable reflection matrix 10a used may be, for
example, a high-resolution surface light modulator with
viscoelastic control layer and mirror layer. Such surface light
modulators with viscoelastic control layers are illustrated, for
example, in the data sheet entitled "Lichtmodulatoren mit
viskoelastischen Steuerschichten" [Light modulators with
viscoelastic control layers] which has been published by the
Fraunhofer Institute for Microelectronic Circuits and Systems, D
01109 Dresden, Germany (information therefrom on pages 44-47 of the
present application). Such a surface light modulator allows
generation of an exposure pattern with spatial resolution for
exposing the reaction carrier.
[0137] Alternatively, the electronically controllable reflection
matrix 10a used may also be a surface light modulator with one or
more micromechanical mirror arrays as is illustrated in the data
sheet entitled "Lichtmodulatoren mit mikromechanischen
Spiegelarrays" [Light modulators with micromechanical mirror
arrays] which has been published by the Fraunhofer Institute for
Microelectronic Circuits and Systems (information therefrom on
pages 48-52 of the present application). Reflection surface light
modulators have also been developed by Texas Instruments.
[0138] Very generally, such electronically controllable mirror
matrices with CMOS 40V technology are very well suited to the
requirements of the present invention, since they can be employed
over a broad spectral range, in particular also in the UV range in
order to generate the desired exposure patterns. This is not true
for UV-sensitive mirror matrices with, for example, 5V
technology.
[0139] Direction of the light path according to FIG. 2 additionally
requires a light deflection element 24 which may be, for example, a
partly transparent mirror which deflects the light coming from the
light source 8 to the reflection matrix 10a and allows the light
which is reflected back from the reflection matrix 10a to pass
through downward to the reaction carrier 4 so that it is possible
to utilize on the reaction carrier 4 or, where appropriate, in the
reaction carrier 4 the exposure pattern generated in accordance
with the control of the reflection matrix 10a for photoactivating,
analyzing or manipulating biochemical processes.
[0140] FIG. 3 shows a variation of the embodiment according to FIG.
2, in which the embodiment of FIG. 3 has a light path for which the
deflection element denoted as 24 in FIG. 2 can be dispensed with,
since the controllable reflection matrix 10a is arranged such that
it can deflect light coming from the light source 8 to the reaction
carrier 4 in accordance with the chosen exposure pattern. When
using a structure corresponding to the variation of FIG. 3, the
image of a carrier with meandering channel is visible in FIG. 13.
In this case, there are no optical elements whatsoever between
carrier and CCD sensor, so this is a lens-less direct detection.
The light source used in this case is a laser.
[0141] FIG. 4 depicts a diagram of another embodiment of an
arrangement for preparing, studying or/and manipulating a carrier
of the present invention. In the embodiment according to FIG. 4,
the illumination matrix used is a matrix arrangement 10b made of
light sources, for example a microlaser array or a microdiode
array. At the moment developments are taking place which are aimed
at putting a multiplicity of microscopically small semiconductor
lasers as tiny powerful light sources on a single chip. A
controllable "light chip" of this type could be used as matrix 10b.
Regarding literature on the background of the "light chips", the
journals: Nature 3, 97, pp. 294-295, 1999 and MPG-Spiegel 4/98, pp.
13-17 may be referred to for example.
[0142] FIG. 5 shows an arrangement in which the detection module 6
with sensor matrix 16 is set up for reflected light or backlight
observation of the reaction carrier 4.
[0143] All arrangements according to FIGS. 1-5 can be used as
light-emission detectors for detecting the optical behavior of a
carrier test area provided with biologically or biochemically
functional materials. This may take place in a manner as is
disclosed in the German patent application 198 39 254.0.
[0144] FIG. 6 shows a section through an embodiment of a carrier 4
of the invention, said embodiment being distinguished by the
illumination matrix 10 being part of the carrier body 4. In this
case, the illumination matrix used is preferably a light valve
matrix which can be disposed of together with its chip carrier 4,
after the carrier is no longer used.
[0145] In the exemplary case of FIG. 6, the carrier body 4 has
capillary channels 30 whose walls serve as preparation surface for
the coating with biologically or biochemically functional
materials. The channels 30 can be selectively charged with the
appropriate reagents. The following details are detectable in FIG.
6: boundary layers 32 with transparent and nontransparent areas 34
and 35, respectively, transparent electrodes 36 with SPD particles
(suspended particles) enclosed between and to be influenced by the
electrodes 36, or alternatively liquid crystals 38.
[0146] FIG. 7 depicts a greatly simplified diagram of a
light-emission detector of the invention in the form of a sandwich
structure composed of light valve matrix 103 (two-dimensional
liquid crystal exposure element), transparent sample carrier 105
with sample material 107 included therein and CCD matrix 109 (image
recorder). The light valve matrix 103 and CCD matrix 109 can be
controlled from a shared (not shown) control unit, for example in
order to switch matrix elements of the light valve matrix and the
CCD matrix assigned to one another into the active state
simultaneously.
[0147] The arrangement shown is suitable, for example, for
measuring the optical absorption of the sample material 107 in the
transparent carrier 105. The sample material 107 may be
microparticles (smart beads), for example. Such an arrangement is
shown in FIG. 12. Here, a commercially available Neubauer cell
counting chamber as transparent carrier 105 has been filled with
colored microparticles 107. When illuminating with a light source
8, consisting of a cold lighr source with fiber coupling-out and
aperture (802), colored microparticles can be detected by the CCD
sensor and the color can be determined by absorption (not visible
in black and white). After labeling the microparticles with
fluorophores, it is possible to detect said fluorophores in the
same way by the CCDs sensor using a suitable light source.
[0148] Means for positioning the light valve matrix relative to the
CCD matrix are not visible in FIG. 7. Said means could be, for
example, means for tilting the light valve matrix 103 relative to
the CCD matrix 109. Of course, it is possible to choose numerous
other possibilities in order to position the light valve matrix 103
and the CCD matrix 109 in the correct position to one another and,
where appropriate, to fix them to one another.
[0149] FIG. 8 shows another arrangement for the spatially resolved
photochemical synthesis of polymer probes on a carrier and/or for
manipulating and/or studying immobilized, biological, biochemically
functional materials. The arrangement according to FIG. 8 can be
conceptually divided into the three functional modules 201, 203 and
206. In this connection, the system module 201 constitutes an
illumination matrix, for example in the form of an LED matrix,
which in a software-controlled manner generates an illumination
pattern which can induce the spatially resolved photochemical
synthesis of polymer probes in the carrier 203. Coupling the
illumination pattern in the carrier 203 is carried out with the aid
of the system component 202. Said system component may be, for
example, a mechanical mask with an aperture for each LED matrix
element. More suitable is the use of micro-optical elements such as
microlenses, for example. Furthermore, said system component may
also be a fused fiber optical taper which makes it possible to
considerably reduce divergence of the light emitted from the
individual light source elements. Opposite the carrier 203, an
optical four-channel detector (preferably a CCD sensor or a CCD
camera) is located on the exit side of the light. The working mode
of said CCD camera is adjusted to the operation of the illumination
matrix 201 with the aid of suitable hardware or software. For
controlling, preference is given to using a personal computer which
controls the illumination matrix and the CCD camera. Alternatively
or additionally, a frequency generator may also be used for
controlling and for electronically synchronizing the illumination
matrix 201 and the, in this case, gated CCD chip 206 with one
another. The latter embodiment will facilitate in particular
fluorimetric detection of the analytes bound to the carrier 203
without it being necessary to introduce additional
frequency-selective elements between the carrier 203 and the
detector matrix 206. However, as has already been mentioned above,
a precondition for this method is to be able to switch the
individual elements of the illumination matrix on or off within a
time range of a few nanoseconds. An alternative to this is an
optical filter 204 which can facilitate spectral separation of the
exciting light and the signal light in fluorimetric detection. When
using a filter wheel 204, it is moreover possible to analyze
simultaneously on the same carrier 203 analytes of different sample
materials which have been labeled with fluorophores of distinctly
different emission maxima. The location-selective reproduction of
the signal light emitted from the carrier 203 on the detector
matrix 206 may optionally be carried out using the component 205.
Said component may either be an optical lens system or a fused
fiber optic taper.
[0150] FIGS. 9, 10 and 11 show further possible embodiments of a
device of the invention. Common to all these embodiments is the
reproduction of the illumination pattern generated by the
illumination matrix 201 on the carrier 203 at a reduced size.
Elements in FIGS. 9, 10 and 11 which correspond to the elements in
FIG. 8 with respect to their function, are marked by in each case
corresponding reference symbols so that in this matter the
description of the exemplary embodiment according to FIG. 8 may be
referred to. For the embodiment according to FIG. 9, the optical
image is reduced by guiding the beam in a fused fiber optic taper
207, whereas in the exemplary embodiment according to FIG. 10
reduction is achieved using a suitable optical lens system 208.
Both micro- and macrolens systems may be employed here. The
exemplary embodiment depicted in FIG. 11 finally uses a combination
of a fused fiber optic taper 207 and an optical lens system
208.
[0151] In summary, the following should also be noted regarding
FIGS. 8-11. They show a device having a light source matrix, a
micro-optical component and also reducing optics for
light-controlled induction of spatially resolved chemical or
biochemical syntheses in one reaction carrier. In the case of using
an LED matrix as light source matrix, it has proved to be
expedient, that no more than 75% of the light source matrix surface
area is covered with LEDs.
[0152] It should be mentioned that one or more gaps between
individual elements of the device may be filled with an optical
fluid.
[0153] With respect to the inventive embodiment depicted in FIG. 3,
FIG. 12 shows an arrangement including a transparent carrier 105,
for example a commercially available Neubauer cell cell chamber
which has been filled with colored microparticles 107. When
illuminating with a light source 8, for example a cold light source
with fiber coupling-out and aperture (802), the colored
microparticles can be detected by the CCD sensor matrix (16) and
the color can be determined by absorption. When labeling the
microparticles with fluorophores, detection by the CCD sensor can
be carried out in an analogous manner.
[0154] FIGS. 14 and 15 were taken from the data sheets:
"Lichtmodulatoren mit viskoelastischen Steuerschichten" [Light
modulators with viscoelastic control layers] and "Lichtmodulatoren
mit mikromechanischen Spiegelarrays" [Light modulators with
micromechanical mirror arrays] of the Fraunhofer Institute for
Microelectronic Circuits and Systems, IMS 1998 (therein in each
case FIG. 1).
Information from the Data Sheet: "Lichtmodulatoren mit
viskoelastischen Steuerschichten" [Light modulators with
viscoelastic control layers]
by the Fraunhofer Institute for Microelectronic Circuits and
Systems, IMS, D-01109 Dresden, Germany
Features
[0155] Viscoelastic control layers form a class of high-resolution
surface light modulators (SLMs) with deformable mirror
arrangements. They consist of an array of independently
controllable control electrodes on an underlying active CMOS
control matrix which is coated with a viscoelastic silicone gel. A
thin aluminum layer is applied thereupon which forms a continuous
mirror surface and has high reflectivity in the complete range from
IR to far UV.
Operation Principle
[0156] FIG. 1 (depicted in FIG. 14 of the present application)
shows diagrammatically the cross section of a viscoelastic control
layer. To activate, a bias is applied between the mirror and the
control electrodes which puts the arrangement in its entire area
under mechanical pressure. The surface initially stays smooth and
acts optically as a planar mirror. Only application of an
additional control voltage with alternating polarity to neighboring
control electrodes leads to a deformation owing to the changing
electrical field strengths. Switching the polarity either for one
or both spatial directions can generate either 1D or 2D sinusoidal
deformation profiles.
[0157] FIG. 2 (of the IMS data sheet) shows in this connection the
surface profiles measured for an embossed-engraved pattern.
Optically, these deformation profiles are phase grids whose grid
period is defined by the distance between the control electrodes.
The incoming light undergoes a phase modulation corresponding to
the differences in the optical path given by the mirror
deformation. Choosing an appropriate deformation amplitude makes it
possible to deflect nearly the entire amount of light into higher
orders of deflection, whereas the light of non-addressed planar
pixels only occupies the zero order.
[0158] In connection with a suitable optical system, it is then
possible to achieve the situation where only light of non-addressed
areas is let through and is projected into the focal plane as
visible intensity pattern.
[0159] Viscoelastic control layers are therefore well suited to
generating phase patterns for optical imaging applications. Using
this technology, an SLM prototype working in binary mode with an
active matrix of 1024.times.2048 pixels and 20.times.20 .mu.m.sup.2
pixel size was developed, with a specific high-voltage CMOS process
being employed to facilitate control voltages of up to .+-.15
V.
[0160] FIG. 3 (of the IMS data sheet) shows in this connection the
diagrammatic layout of the active control matrix. The operation of
this prototype was successfully demonstrated in an application for
fast direct laser exposure of sub-y structures. Said prototype
served to generate phase patterns from the CAD layout data of IC
mask layers, which patterns were then converted into an intensity
image for the photoresist structuring with the aid of the optical
system.
[0161] At present, light modulators are being developed which allow
4-bit analog operation and graduation of the image field size in
steps of 256 pixels for each direction.
Applications
[0162] Light modulators with viscoelastic control layers open up
many new application possibilities:
Display Technology:
[0163] Video and data projection [0164] Head-up displays
Information Technology:
[0164] [0165] Optical image and data processing [0166] Optical
storage
Production Technology:
[0166] [0167] Mask-free direct writing [0168] Laser ablation and
production
TABLE-US-00001 [0168] Technical parameters Pixel size >16
.times. 16 .mu.m.sup.2 Pixel number 256 .times. 256 . . . 1024
.times. 2048 Profile 1D, 2D sinusoidal Modulation phase-modulating
Operation binary or 4-bit analog Deformation amplitude 0 . . . 150
nm Control graph nearly linear Adjustment time <2 ms Data inputs
16, 32, 48, 64 channels 4 bit, 5 V Image frequency 100 Hz . . . 500
Hz Optical filling 100% Reflectivity >90% IR . . . DUV) far UV
Construction technology ceramic PGA shell
User Evaluation Kit
[0169] In order to provide the possibility of testing all
fundamental SLM functions in a user-specific environment, a user
evaluation kit containing all components for user-specific image
programming of the SLMs was developed.
TABLE-US-00002 SLM Pixel size 16 .times. 16, 20 .times. 20, 24
.times. 24 .mu.m.sup.2 Pixel number 256 (160) .times. 256 Pixel
design customer-specific Operation 4-bit analog
TABLE-US-00003 SLM board RAM Storage of 2 images Image frequency 1
Hz (PG to RAM) 500 Hz (RAM to SLM) I/O signals Matrix Trigger,
Matrix Ready
Data Transfer
[0170] via cable connection and digital I/O interface card for ISA
slot on the PC
Software
[0170] [0171] Conversion of user image data from bitmap into SLM
data format [0172] Control functions for data transfer [0173]
Setting the control voltage level for 4-bit grayscale
Requirements
[0173] [0174] Windows-compatible PC [0175] Image pattern generation
in bitmap data format, for example using Paintbrush Information
from the Data Sheet: "Lichtmodulatoren mit mikromechanischen
Spiegelarrays" [Light modulators with micromechanical mirror
arrays]
by the Fraunhofer Institute for Microelectronic Circuits and
Systems, IMS, D-01109 Dresden, Germany
Features
[0176] Micromechanical mirror arrays form a class of
high-resolution surface light modulators (SLMs) with deformable
mirror arrangements. They consist of an array of independently
controllable micromirrors which are produced on an underlying
active matrix control circuit in a completely CMOS-compatible
process using the methods of surface micromechanics. The process
only needs three additional masks and thus allow easy adaptation of
the light-modulating properties to a wide variety of
application-specific requirements by merely changing the mirror
architecture.
Operation Principle
[0177] The micromirrors are produced using a sacrificial layer
technique, so that hanging mirror elements are created above a
cavity with underlying control electrode.
[0178] Mirror and supporting beams consist to the same extent of
aluminum in order to guarantee high reflectivity over a broad
spectral range from IR to far UV.
[0179] Activation takes place by applying a control voltage between
mirror and control electrode so that the mirrors are deformed into
the cavity due to the action of electrostatic forces. The
differences in the optical path related thereto lead to a
corresponding phase modulation in the incoming light. The
deformation profile and thus the light-modulating properties depend
in this context strongly on the particular mirror architecture.
Here, three fundamental cases, phase-modulating, phase-shifting and
light-deflecting, can be distinguished.
[0180] From the multiplicity of possible pixel architectures, the
two structures from FIG. 1 (depicted in FIG. 15 of the present
application) have been studied in more detail.
[0181] In the first variation, electronic deformation of four
identical mirror segments generates optical phase grids in which
one pixel defines in each case one grid period with inverse
pyramidal phase profile. Said variation is well suited to generate
phase patterns for optical imaging applications.
[0182] The second variation consists of a mirror plate held by four
arms, which mirror plate delivers, when electronically controlled,
a planar piston-like descending movement and thus allows setting
the phase of the incoming light for each pixel. This variation is
well suited to phase front correction in adaptive optics.
[0183] Such micromirrors have already been built on passive
matrices for studying the electromechanical properties (FIG. 2, 3
of the IMS data sheet). The measured graphs in FIG. 4 (of the IMS
data sheet) show in this connection the typical deformation
behavior. In the analog field, deformation increases almost
quadratic with the control voltage. Above the so-called pull-in
point the mirrors, however, owing to the co-coupling via the
electric field, switch spontaneously to the fully extended state in
which only binary operation is still possible. In order to set the
mirrors finally back to an equilibrium between mechanical and
electrical powers, an appropriate reduction of the control voltage
is necessary.
Applications
[0184] Light modulators with micromechanical mirrors open up a
multiplicity of application possibilities:
Display Technology:
[0185] Video and data projection [0186] Head-up displays
Information Technology:
[0186] [0187] Optical image and data processing [0188] Optical
storage
Phase Front Correction of Adaptive Optics
Production Technology:
[0188] [0189] Mask-free direct writing [0190] Laser ablation and
production
Medical Technology:
[0190] [0191] Laser scanning tomography [0192] Laser surgery [0193]
Endoscopic head-up displays
TABLE-US-00004 [0193] Technical parameters Pixel size >16
.times. 16 .mu.m.sup.2 Pixel number 256 .times. 256 . . . 1024
.times. 2048 Pixel design customer-specific, pyramidal, descending,
torsion elements, Profile etc., pyramidal, rectangular, sawtooth,
etc. Modulation phase-modulating or -shifting, deflecting Operation
binary or 4-bit analog Deformation amplitude 0 . . . 1.2 .mu.m
(analog) up to 5.0 .mu.m (binary) Control graph nonlinear
Adjustment time 10 .mu.s (typ.) Image frequency 100 Hz . . . 1 kHz
Optical filling 80 . . . 90% Reflectivity >90% (IR . . . DUV)
far UV
User Evaluation Kit
[0194] In order to provide the possibility of testing all
fundamental SLM functions in a user-specific environment, a user
evaluation kit containing all components for user-specific image
programming of the SLMs was developed.
TABLE-US-00005 SLM Pixel size 16 .times. 16, 20 .times. 20, 24
.times. 24 .mu.m.sup.2 Pixel number 256 (160) .times. 256 Pixel
design customer-specific Operation 4-bit analog
TABLE-US-00006 SLM board RAM Storage of 4 images Image frequency 1
Hz (PC to RAM) 500 Hz (RAM to SLM) I/O signals Matrix Trigger,
Matrix Ready
Data Transfer
[0195] via cable connection and digital I/O interface card for ISA
slot on the PC
Software
[0195] [0196] Conversion of user image data from bitmap into SLM
data format [0197] Control functions for data transfer [0198]
Setting the control voltage level for 4-bit grayscale
Requirements
[0198] [0199] Windows-compatible PC [0200] Image pattern generation
in bitmap data format, for example using Paintbrush
* * * * *