U.S. patent application number 11/775791 was filed with the patent office on 2008-01-31 for micro impedance pump for fluid logic, mixing and separation.
Invention is credited to Morteza Gharib, Derek Rinderknecht.
Application Number | 20080025853 11/775791 |
Document ID | / |
Family ID | 38986505 |
Filed Date | 2008-01-31 |
United States Patent
Application |
20080025853 |
Kind Code |
A1 |
Gharib; Morteza ; et
al. |
January 31, 2008 |
Micro Impedance Pump For Fluid Logic, Mixing and Separation
Abstract
An impedance pump system formed on a rigid substrate is
substantially planar, in a plane defined by a substrate. A micro
machined opening is made in the substrate, and an impedance pump,
formed by a lumen which can be a tubular elastic device having two
different fluidic impedances with a wave reflection site
therebetween, is formed within the opening. An actuator is formed
to pump using the device.
Inventors: |
Gharib; Morteza; (San
Marino, CA) ; Rinderknecht; Derek; (Arcadia,
CA) |
Correspondence
Address: |
Law Office of Scott C Harris
PO Box 1389
Rancho Santa Fe
CA
92067
US
|
Family ID: |
38986505 |
Appl. No.: |
11/775791 |
Filed: |
July 10, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60819871 |
Jul 10, 2006 |
|
|
|
60842758 |
Sep 7, 2006 |
|
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Current U.S.
Class: |
417/413.2 |
Current CPC
Class: |
F04B 43/095
20130101 |
Class at
Publication: |
417/413.2 |
International
Class: |
F04B 17/00 20060101
F04B017/00 |
Claims
1. A pumping system, comprising: a substrate, formed of a material
that can be micromachined; at least one lumen opening formed in
said substrate, said lumen opening being substantially extending
along an axis of the substrate, said lumen opening including at
least a first portion having a first fluidic characteristic, and a
second portion having at least a second fluidic characteristic, and
a wave reflection interface between said first and second portions;
an actuator, formed adjacent said lumen opening in said substrate,
and formed to actuate in an area of the lumen opening to pump fluid
within the lumen opening; and a controller connection to said
actuator, also formed in said substrate, operative to allow control
of said actuator.
2. A system as in claim 1, further comprising a tubular material in
said lumen opening.
3. A system as in claim 1, wherein said lumen opening comprises an
opening which is etched in the substrate material, and further
comprising at least one deformable material within the etched
substrate material.
4. A system as in claim 3, further comprising a second material, in
said lumen opening, the first and second materials collectively
forming a multilayer lumen.
5. A system as in claim 4, wherein said second material is a rigid
material.
6. A system as in claim 4, wherein said actuator is formed between
said first and second materials.
7. A system as in claim 3, wherein said actuator is formed outside
of said deformable material.
8. A system as in claim 1, further comprising a second
actuator.
9. A system as in claim 1, further comprising a controller, coupled
to said controller connection, which operates to excite said lumen
in a way that creates constructive wave interactions based on
reflections from said wave reflection interface.
10. A system as in claim 1, wherein said actuator is a deposited
thin film.
11. A system as in claim 1, wherein said walls are formed of a
rigid material.
12. A system as in claim 1, wherein said walls are formed by
micro-molding.
13. A method comprising: Micromachining at least one lumen opening
formed in a substrate to extend along an axis of the substrate,
said micromachining forming an opening including at least a first
portion having a first fluidic characteristic, and a second portion
having at least a second fluidic characteristic, and a wave
reflection interface between said first and second portions;
Forming an actuator adjacent said lumen opening in said substrate
in a location to actuate in an area of the lumen opening and to
pump fluid within the lumen opening; and Controlling the actuator
in a way to form constructive wave reflection at said wave
reflection interface and to pump fluid.
14. A method as in claim 13, further comprising depositing a
tubular material in said lumen opening.
15. A method as in claim 14, wherein said tubular material includes
at least one deformable material within the etched substrate
material.
16. A method as in claim 15, further comprising depositing a second
material in said lumen opening, the first and second materials
collectively forming a multilayer lumen material.
17. A method as in claim 16, wherein said second material is a
rigid material.
18. A method as in claim 16, wherein said actuator is formed
between said first and second materials.
19. A method as in claim 15, wherein said actuator is formed
outside of said deformable material.
20. A method as in claim 1, further comprising using a second
actuator in addition to said actuator, to pump fluids.
21. A method as in claim 13, wherein said actuator includes a
deposited thin film.
22. A pumping system, comprising: at least one lumen, formed of a
first layer that is substantially rigid, and a second layer, inside
said first layer, that is flexible, said lumen having at least a
first portion having a first fluidic characteristic and a second
portion having at least a second fluidic characteristic with at
wave reflection interface between said first and second portions;
an actuator, formed adjacent said flexible portion of said lumen to
actuate in an area of the lumen in a way that allows pumping of
fluid within the lumen; and a controller connection to said
actuator, also formed in said substrate, operative to allow control
of said actuator.
23. A system as in claim 22, wherein said lumen is tubular in
shape.
24. A system as in claim 22, wherein said actuator is formed
between said first and second layers.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional
Applications 60/819,871, filed Jul. 10, 2006 and 60/842,758, filed
Sep. 7, 2006. The disclosure of the prior applications are
considered part of (and are incorporated by reference in) the
disclosure of this application.
BACKGROUND
[0002] A valveless microimpedance pump is described in U.S. Pat.
No. 7,163,385. This pump enables pumping fluid using fluidic
differences between conduit types, and pumps without using one way
valves or the like.
SUMMARY
[0003] An embodiment describes a modular plug and play micropump
which can be used to drive and control microfluidic systems.
[0004] An embodiment is planar in format and modular.
[0005] An embodiment uses rigid materials, and a planar format for
microfluidic applications.
[0006] An embodiment uses rigid and/or flexible micro impedance
pumps formed by masking and depositing metals, micromachining
and/or etching.
[0007] An embodiment uses both flexible and rigid materials.
[0008] An embodiment uses an embedded actuator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 shows an embodiment of a pump device on a modular
chip; and
[0010] FIG. 2 shows a pump device which has two actuators.
DETAILED DESCRIPTION
[0011] An embodiment uses an impedance pump of the type disclosed
in U.S. Pat. No. 7,163,385, the disclosure of which are here with
incorporated by reference.
[0012] According to an embodiment, a modular plug-and-play type
micropump is used within a microfluidic system. The device is
planar and can be integrated into different kinds of technologies
including Web on-chip technology or the like. The channels can have
characteristic dimensions, for example, on the order of a micron.
Therefore, this can easily be integrated into current lab-on-chip
technologies. Integration of a compact pump into current
microfluidic systems creates the potential for true lab on chip
devices where not only the channels have characteristic dimensions
on the order of a micron but also the components on which they
operate.
[0013] The impedance pump is formed as shown in FIG. 1. A substrate
199 can be a semiconductor substrate, e.g., a semiconductor chip,
or micromachined substrate or circuit board. All of the parts
described herein are formed on that substrate.
[0014] A flexible lumen 100 includes a first part 105 with a first
fluidic characteristic and a second part 110 with a second fluidic
characteristic. The lumen extends along an axis of the substrate.
The lumen 100 is asymmetrically excited by an excitation part 120,
which can be a pincher that constricts at least a part of the outer
cross section of the lumen, to form a pressure wave. First part 105
of the lumen 100 has a different fluidic characteristic than second
part 110 of the lumen. For example, the different fluidic
characteristic between the two parts can be compliance, geometry,
or any other physical property which creates a site for wave
reflection. Moreover, there can be multiple different parts, in
addition to the two parts shown in FIG. 1.
[0015] The wave reflection sites, comprised of a mismatch in
impedance at the interface of different materials 108 and/or by a
change in geometry, is excited asymmetrically with respect to the
fluidic system to drive flow.
[0016] The actuator 120 is controlled by a controller 125 which can
operate according to a prestored procedure. The controller 125 can
carry out excitation over a specific range of frequencies to create
constructive wave interactions based on reflections from the
reflection area 108. The constructive wave interaction creates a
pressure gradient to drive the flow. In an embodiment, the
contoller seeks resonance or other optimum characteristics in the
constructive wave interference.
[0017] The controller can alternatively be off chip, in which case,
an input line is substituted for the controller 125.
[0018] Other fluidic parts shown generically as 130 can also be
added, which can include diffusers, valves and other such flow
rectifiers. These can increase performance as desirable. The other
fluidic parts 130 can be passive or car also be controlled by the
controller 125.
[0019] In the embodiment, the impedance pump is planar, with all of
the structure on the same plane defining a plane of the substrate.
The lumen may be tubular, for example, and the actuator 120 may be
pinchers either surrounding the lumen, or on positions on the plane
defined by the substrate.
[0020] An embodiment uses rigid materials for many parts of the
lumen, so that both flexible and rigid materials can both be used.
The materials, formed of rigid and/or flexible micro impedance
pumps formed by masking and depositing metals, micromachining
and/or etching.
[0021] Actuator 120 can be formed of a deposited active thin-film
such as piezoelectrics, magnetostrictive or ferroelectrics. Other
deposited films can include structure for actuating
electrostatically, magnetically, pneumatically, hydraulically or
any other actuation method. If the excitation device 120 is a
piezoelectric device, it can work by uni-morph or bi-morph.
[0022] In a first embodiment, the piezoelectric element can be in
contact with the outside of the walls. A second embodiment in FIG.
2 embeds the piezoelectric element 205 within at least one of the
walls capable of transmitting an excitation.
[0023] These structures can be created using soft lithography to
fabricate them monolithically making them low cost, disposable and
easily added to current lab-on-chip designs.
[0024] In an embodiment, the walls themselves can be formed of
polymeric materials such as silicone, polyisoprene, polyimide,
polyurethane or parylene. Alternatively, the walls can be made of
rigid materials such as silicon, glass, or metallic materials such
as nickel, titanium, or iron based metals such as stainless steel.
The walls of the lumen may be formed inside openings that are
micromachined in the substrate 100.
[0025] A first embodiment describes monolithically forming the
layers. Alternatively, the unit may be built in a series of layers
as in FIG. 2, where one or more of the layers 200 may function as
the excitation transmitting wall. The excitation transmitting wall
200 should be at least partly deformable so allow transmitting the
excitation. The outer wall can be deformable, or can be rigid,
e.g., metallic. The layers can be formed by means of a micromolding
process such as spinning down a photo resist, exposure, and
development, patterning of the pump material and forming the device
on a separate substrate. A different micromolding process can
alternatively be used, such as spinning down a photo resist,
exposure, and development, patterning of the pump material and
subsequent removal of the resist through access ports. An
alternative micromolding process may use imprint lithography.
[0026] This device makes possible the use of other such medical
devices are also possible due to the new packaging. It can be used
in flexible nature of the micropump such as active coronary bypass
stents and blood flow assist devices. Such a modular micropump can
also easily be micromachined or etched into stiffer materials such
as metals or silicon to be structurally rigid for high pressure
operation. At least one wall of the lumen, should be deformable to
allow actuation.
[0027] Multiple pumps can be added in series or in parallel
allowing for a vast range of flow outputs as well as complex
patterns for fluidic logic. Many configurations are therefore
possible with minimal connections to the chip. The ability to have
many modules allows precise sample volumes to be delivered in a
controlled manner.
[0028] The pump operates in pulses. The pulsatile nature of the
flow provides enhanced mixing of reactants on a microscale due to
the extremely high transient oscillatory fluid velocities. In
addition, the reversible nature of the micropump further enhances
on-chip control. A modular micro impedance based pumping system
therefore has vast potential for application such as cell sorting,
as well as chemical mixing and analysis for high throughput drug
screening.
[0029] In a first embodiment, the device can have a closed flexible
cavity connected at either end to create closed channels of
different compliance, geometry or any other physical property which
creates a site for wave reflection along which an excitation or
compression occurs located asymmetrically with respect to the fluid
system.
[0030] In another embodiment, the lumen 100 can be open at both
ends, defining a fluid input 99, and a fluid outlet 101.
[0031] Another embodiment may use multiple pumps are used in a
single layer or multiple layers to enable operation in series or
parallel to enhance performance.
[0032] The FIG. 2 embodiment uses two separate actuators, e.g., two
or more piezoelectric elements 205, 210, placed in contact with the
same wall or more than one wall such as opposing walls capable of
transmitting an excitation. These actuators, in this embodiment,
may be as disclosed above, with all the features disclosed above,
e.g., the elements may be uni-morph or bi-morph, in contact with or
embedded within at least one of the walls capable of transmitting
an excitation.
[0033] According to an aspect, the micropump can completely close
the main cavity and therefore function as a valve.
[0034] The general structure and techniques, and more specific
embodiments which can be used to effect different ways of carrying
out the more general goals are described herein.
[0035] Although only a few embodiments have been disclosed in
detail above, other embodiments are possible and the inventor (s)
intend these to be encompassed within this specification. The
specification describes specific examples to accomplish a more
general goal that may be accomplished in another way. This
disclosure is intended to be exemplary, and the claims are intended
to cover any modification or alternative which might be predictable
to a person having ordinary skill in the art. For example,
different materials can be used.
[0036] Also, the inventor(s) intend that only those claims which
use the words "means for" are intended to be interpreted under 35
USC 112, sixth paragraph. Moreover, no limitations from the
specification are intended to be read into any claims, unless those
limitations are expressly included in the claims. The computers
described herein may be any kind of computer, either general
purpose, or some specific purpose computer such as a workstation.
The computer may be an Intel (e.g., Pentium or Core 2 duo) or AML)
based computer, running Windows XP or Linux, or may be a Macintosh
computer. The computer may also be a handheld computer, such as a
PDA, cellphone, or laptop.
[0037] The programs may be written in C or Python, or Java, Brew or
any other programming language. The programs may be resident on a
storage medium, e.g., magnetic or optical, e.g. the computer hard
drive, a removable disk or media such as a memory stick or SD
media, wired or wireless network based or Bluetooth based Network
Attached Storage (NAS), or other removable medium or other
removable medium. The programs may also be run over a network, for
example, with a server or other machine sending signals to the
local machine, which allows the local machine to carry out the
operations described herein.
[0038] Where a specific numerical value is mentioned herein, it
should be considered that the value may be increased or decreased
by 20%, while still staying within the teachings of the present
application, unless some different range is specifically mentioned.
However, the tubing may be any size that is appropriate for
micromaching. For example the lumens described herein can be tubing
having a diameter of anything between 500 nm and 5 mm, typically 1
um or 5 um.
[0039] Where a specified logical sense is used, the opposite
logical sense is also intended to be encompassed.
* * * * *