U.S. patent application number 11/924931 was filed with the patent office on 2013-05-16 for aligning nanotubes.
The applicant listed for this patent is Keith Daniel Humfeld. Invention is credited to Keith Daniel Humfeld.
Application Number | 20130122214 11/924931 |
Document ID | / |
Family ID | 48280905 |
Filed Date | 2013-05-16 |
United States Patent
Application |
20130122214 |
Kind Code |
A1 |
Humfeld; Keith Daniel |
May 16, 2013 |
ALIGNING NANOTUBES
Abstract
A method for aligning nanotubes. In one embodiment, a method is
used to align nanotubes. A bath with nanotubes dispersed on the
surface of a solution is provided. An attachment surface is
provided to attach the nanotubes. The attachment surface is placed
into the bath at an angle of around ninety degrees relative to a
surface of the bath. The attachment surface is removed from the
bath at a rate sufficient to apply a velocity to the nanotubes in
the bath of nanotubes such that the nanotubes are aligned on the
attachment surface in a direction that is substantially parallel to
the direction at which the substrate is removed to form a plurality
of aligned nanotubes.
Inventors: |
Humfeld; Keith Daniel;
(Garden Grove, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Humfeld; Keith Daniel |
Garden Grove |
CA |
US |
|
|
Family ID: |
48280905 |
Appl. No.: |
11/924931 |
Filed: |
October 26, 2007 |
Current U.S.
Class: |
427/551 ;
427/331; 977/742 |
Current CPC
Class: |
B05D 1/202 20130101;
B05D 1/18 20130101; B82Y 30/00 20130101; C01B 2202/08 20130101;
B82Y 40/00 20130101; C01B 32/168 20170801 |
Class at
Publication: |
427/551 ;
427/331; 977/742 |
International
Class: |
B05D 1/18 20060101
B05D001/18 |
Claims
1. A method for aligning nanotubes, the method comprising:
dispersing nanotubes in a solution along a surface of the solution
to form a first bath; placing an attachment surface into the first
bath at an angle of around ninety degrees relative to a surface of
the first bath; removing the attachment surface from the first bath
at a first rate to form a covered attachment surface, the first
rate sufficient to apply a velocity to the nanotubes in the first
bath such that a first plurality of nanotubes align on the
attachment surface in a direction that is substantially parallel to
the direction at which the attachment surface is removed to form a
plurality of aligned nanotubes; rotating the covered attachment
surface to form a rotated attachment surface; placing the rotated
attachment surface into a second bath; and applying energy to the
plurality of aligned nanotubes, the energy sufficient to form a
number of links between a first number of nanotubes in the
plurality of aligned nanotubes and a second number of nanotubes in
the second bath.
2. (canceled)
3. The method of claim 1 further comprising: pre-aligning the
nanotubes prior to placing the attachment surface into the
bath.
4. The method of claim 1, wherein the solution is an aqueous
surfactant solution.
5. The method of claim 4, wherein the surfactant is selected from
one of stearic acid and stearyl alcohol.
6-9. (canceled)
10. A method for aligning nanotubes, the method comprising:
dispersing a plurality of nanotubes on a surface of a first
solution to form a plurality of dispersed nanotubes; placing a
substrate with a surface into the first solution in which the
surface is at an angle relative to a surface of the first solution;
removing the substrate from the first solution at the angle and at
a first rate to form a covered substrate, the first rate sufficient
to apply a velocity to the plurality of dispersed nanotubes such
that a number of the plurality of dispersed nanotubes align on the
substrate in a direction that is substantially parallel to the
direction at which the substrate is removed to form a plurality of
aligned nanotubes; rotating the covered substrate to form a rotated
substrate; placing the rotated substrate into a second solution at
the angle and at a second rate, the second rate sufficient to apply
a second velocity gradient to a second plurality of nanotubes in
the second solution such that the second plurality of nanotubes are
aligned on the substrate in a direction that is substantially
parallel to a direction in which the substrate is placed into the
second solution; and applying energy to the plurality of aligned
nanotubes, the energy sufficient to form a number of links between
a first number of nanotubes in the plurality of aligned nanotubes
and a second number of nanotubes in the second plurality of
nanotubes.
11-13. (canceled)
14. The method of claim 10, wherein the angle is around ninety
degrees.
15. The method of claim 10, wherein the solution is an aqueous
surfactant solution.
16. The method of claim 15, wherein the surfactant is selected from
stearic acid and stearyl alcohol.
17. The method of claim 10, wherein the dispersing step comprises:
dispersing the plurality of nanotubes in the solution in a Langmuir
Blodgett apparatus to form the plurality of dispersed
nanotubes.
18. The method of claim 10, wherein the substrate is formed from
amorphous silicon dioxide.
19. The method of claim 10, wherein the plurality of nanotubes are
selected from one of carbon nanotubes and gallium nitride
nanotubes.
20. (canceled)
21. The method of claim 1, wherein applying the energy to the
plurality of aligned nanotubes comprises: applying the energy to
the plurality of aligned nanotubes below an instability point of
the second bath.
22. (canceled)
23. The method of claim 10, wherein applying the energy to the
plurality of aligned nanotubes comprises: applying the energy to
the plurality of aligned nanotubes below an instability point of
the second solution.
24. (canceled)
25. The method of claim 1, wherein the second bath comprises the
first bath after the attachment surface is removed from the first
bath.
26. The method of claim 10, wherein the second solution comprises
the first solution after the substrate is removed from the first
solution.
27. The method of claim 1, wherein the energy comprises x-ray
energy.
28. The method of claim 10, wherein the energy comprises x-ray
energy.
29. The method of claim 1, wherein applying energy to the plurality
of aligned nanotubes forms a nanotube mesh.
30. The method of claim 10, wherein applying energy to the
plurality of aligned nanotubes forms a nanotube mesh.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present disclosure is related to the following patent
application: entitled "Nanotube Mesh", Ser. No. ______, attorney
docket no. 07-0682; filed even date hereof, assigned to the same
assignee, and incorporated herein by reference.
BACKGROUND INFORMATION
[0002] 1. Field:
[0003] The present disclosure relates generally to nanotechnology
and in particular to nanotubes. Still more particularly, the
present disclosure relates to a method and apparatus for a
structure made of nanotubes.
[0004] 2. Background:
[0005] Nanotechnology is a field of applied science and technology
in which the control of matter on a molecular level occurs in
scales less than one micrometer. This type of technology also
relates to the fabrication of devices the size of one to
one-hundred nanometers. This type of technology may draw from
different fields, such as applied physics, material science,
colloidal science, device physics, mechanical engineering, and even
electrical engineering.
[0006] One type of nanotechnology involves nanotubes. A single-wall
nanotube may be formed from a one-atom thick sheet of graphite
rolled into a seamless cylinder with a diameter that may be one
nanometer. This type of nanotube is a carbon nanotube. The
resulting structure is a nanotube having a length to diameter ratio
that may exceed ten thousand. Nanotubes may have various
configurations. For example, nanotubes that are made of carbon may
be single-walled or multi-walled.
[0007] Carbon nanotubes have properties that make them potentially
useful in many applications. These types of nanotubes may exhibit
extraordinary strength and unique electrical properties. Further,
nanotubes are efficient conductors of heat. Other types of
nanotubes, such as inorganic nanotubes, have also been
synthesized.
[0008] Limitations on use of carbon nanotubes include, for example,
the length at which these tubes may be strung together. The longest
carbon nanotube currently produced is eighteen millimeters long,
making these types of nanotubes practically useless for large scale
applications. As a result, many times carbon nanotubes are
incorporated with other materials. This type of use may help
increase the strength or other desirable properties of those
materials. By dispersing or placing nanotubes into other
components, the strength of those components is increased but not
as great as nanotubes that are by themselves.
[0009] In bulk, materials including nanotubes may not have the same
tensile strength as individual nanotubes. These types of
configurations, however, may yield strengths that are sufficient
for many applications. For example, carbon nanotubes have been used
as composite fibers in polymers to improve mechanical, thermal, and
electrical properties of various products. Nanotubes also may be
used in various structural products, such as clothes, combat
jackets, concrete, sports equipment, and bridges. Other uses for
nanotubes include computer circuits, conductive films, air filters,
water filters, and non-stick surfaces.
SUMMARY
[0010] The different advantageous embodiments provide a method for
aligning nanotubes. In one embodiment, a method is used to align
nanotubes. A bath with nanotubes dispersed on the surface of a
solution is provided. An attachment surface is provided to attach
the nanotubes. The attachment surface is placed into the bath at an
angle of around ninety degrees relative to a surface of the bath.
The attachment surface is removed from the bath at a rate
sufficient to apply a velocity to the nanotubes in the bath of
nanotubes such that the nanotubes are aligned on the attachment
surface in a direction that is substantially parallel to the
direction at which the substrate is removed to form a plurality of
aligned nanotubes.
[0011] In another embodiment, a method is used for aligning
nanotubes. A plurality of nanotubes is dispersed on the surface of
a solution to form a plurality of dispersed nanotubes. A substrate
with a surface is placed into the solution in which the surface is
at an angle relative to a surface of the solution. The substrate is
removed from the solution at the angle and at a rate sufficient to
apply a velocity to the plurality of nanotubes such that the
plurality of nanotubes align in a direction that is substantially
parallel to the direction at which the substrate is removed to form
a plurality of aligned nanotubes.
[0012] The features, functions, and advantages can be achieved
independently in various embodiments of the present invention or
may be combined in yet other embodiments in which further details
can be seen with reference to the following description and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The novel features believed characteristic of the invention
are set forth in the appended claims. The invention itself,
however, as well as a preferred mode of use, further objectives and
advantages thereof, will best be understood by reference to the
following detailed description of an advantageous embodiment of the
present invention when read in conjunction with the accompanying
drawings, wherein:
[0014] FIG. 1 is a diagram illustrating an aircraft manufacturing
and service method in which an advantageous embodiment the present
invention may be implemented;
[0015] FIG. 2 is a diagram of an aircraft in which an in accordance
with an advantageous embodiment;
[0016] FIG. 3 is a diagram illustrating a nanotube mesh
manufacturing system in accordance with an advantageous
embodiment;
[0017] FIG. 4 is a diagram illustrating the formation of a nanotube
mesh in accordance with an advantageous embodiment;
[0018] FIG. 5 is a top view of an apparatus in a nanotube alignment
system in accordance with an advantageous embodiment;
[0019] FIG. 6 is a diagram illustrating the pre-alignment of
nanotubes in an apparatus in a nanotube alignment system in
accordance with an advantageous embodiment;
[0020] FIG. 7 provides a cross-sectional view of an alignment
device in accordance with an advantageous embodiment;
[0021] FIG. 8 is a diagram illustrating the aligning of nanotubes
on a substrate in accordance with an advantageous embodiment;
[0022] FIG. 9 is a more detailed diagram illustrating the aligning
of nanotubes on a substrate in accordance with an advantageous
embodiment;
[0023] FIG. 10 is a diagram illustrating the creation of a second
sheet of nanotubes in accordance with an advantageous
embodiment;
[0024] FIG. 11 is a flowchart of a process for aligning nanotubes
in accordance with an advantageous embodiment; and
[0025] FIG. 12 is a flowchart of a process for manufacturing
nanotube mesh in accordance with an advantageous embodiment.
DETAILED DESCRIPTION
[0026] Referring more particularly to the drawings, embodiments of
the disclosure may be described in the context of aircraft
manufacturing and service method 100 as shown in FIG. 1 and
aircraft 200 as shown in FIG. 2. Turning first to FIG. 1, a diagram
illustrating an aircraft manufacturing and service method is
depicted in accordance with an advantageous embodiment. During
pre-production, exemplary aircraft manufacturing and service method
100 may include specification and design 102 of aircraft 200 in
FIG. 2 and material procurement 104. During production, component
and subassembly manufacturing 106 and system integration 108 of
aircraft 200 in FIG. 2 takes place. Thereafter, aircraft 200 in
FIG. 2 may go through certification and delivery 110 in order to be
placed in service 112. While in service by a customer, aircraft 200
in FIG. 2 is scheduled for routine maintenance and service 114,
which may include modification, reconfiguration, refurbishment, and
other maintenance or service.
[0027] Each of the processes of aircraft manufacturing and service
method 100 may be performed or carried out by a system integrator,
a third party, and/or an operator. In these examples, the operator
may be a customer. For the purposes of this description, a system
integrator may include, without limitation, any number of aircraft
manufacturers and major-system subcontractors; a third party may
include, without limitation, any number of venders, subcontractors,
and suppliers; and an operator may be an airline, leasing company,
military entity, service organization, and so on.
[0028] With reference now to FIG. 2, a diagram of an aircraft is
depicted in which an advantageous embodiment may be implemented. In
this example, aircraft 200 is produced by aircraft manufacturing
and service method 100 in FIG. 1 and may include airframe 202 with
a plurality of systems 204 and interior 206. Examples of systems
204 include one or more of propulsion system 208, electrical system
210, hydraulic system 212, and environmental system 214. However,
any number of other systems may be included. Although an aerospace
example is shown, different advantageous embodiments may be applied
to other industries, such as the automotive industry.
[0029] Apparatus and methods embodied herein may be employed during
any one or more of the stages of aircraft manufacturing and service
method 100 in FIG. 1. For example, components or subassemblies
produced in component and subassembly manufacturing 106 in FIG. 1
may be fabricated or manufactured in a manner similar to components
or subassemblies produced while aircraft 200 is in service 112 in
FIG. 1.
[0030] Also, one or more apparatus embodiments, method embodiments,
or a combination thereof may be utilized during production stages,
such as component and subassembly manufacturing 106 and system
integration 108 in FIG. 1, for example, without limitation, by
substantially expediting the assembly of or reducing the cost of
aircraft 200. Similarly, one or more of apparatus embodiments,
method embodiments, or a combination thereof may be utilized while
aircraft 200 is in service 112 or during maintenance and service
114 in FIG. 1.
[0031] As a specific non-limiting example, nanotube meshes may be
implemented in the coating of different surfaces for components of
aircraft 200. For example, nanotube meshes, in the advantageous
embodiments, may be used on the exterior surfaces of aircraft 200.
These meshes may be added before and/or after a protective coating,
such as paint, has been applied to aircraft 200. As a result,
nanotube meshes may make the exterior surfaces potentially more
aerodynamic and more resistant to environmental wear. Further,
nanotube meshes also may be used in other components. For example,
nanotube meshes may be added to composite components within
airframe 202 to increase the strength of these components.
[0032] Further, nanotube meshes also may be used in interior
components in aircraft 200, such as in seating, trays, closets, and
other components to reduce the bulk and weight of the components as
well as increase the strength of the components.
[0033] In view of existing limitations for using carbon nanotubes,
the different advantageous embodiments provide a method and
apparatus for creating nanotube meshes. An apparatus has a first
sheet and a second sheet. The first sheet has first nanotubes
aligned in a direction approximately parallel to each other. The
second sheet has second nanotubes aligned in a direction
approximately parallel to each other, wherein the first layer is
attached to the second layer at set of points at which the first
nanotubes contact the second nanotubes to form a nanotube mesh.
These sheets also may be referred to as layers.
[0034] Turning now to FIG. 3, a diagram illustrating a nanotube
mesh manufacturing system is depicted in accordance with an
advantageous embodiment. In this example, manufacturing environment
300 includes nanotube alignment system 302, nanotube mesh synthesis
system 304, and product manufacturing system 306.
[0035] Nanotubes 308 are supplied to nanotube alignment system 302
to generate nanotube sheets 310. Nanotubes 308, in these examples,
are carbon nanotubes. In other embodiments, nanotubes 308 may take
the form of other types of nanotubes, such as inorganic nanotubes.
Nanotubes 308 may be all of the same size or, in some cases, a
mixture of nanotubes with different sizes may be present within
nanotubes 308. Nanotubes 308 may be obtained from a variety of
sources. For example, single-wall carbon nanotubes may be obtained
from Sigma-Aldrich Co. and Carbon Nanotechnologies, Inc.
[0036] Nanotube alignment system 302 generates nanotube sheets 310.
In these examples, a sheet within nanotube sheets 310 is a
plurality of nanotubes that are in an aligned form. In other words,
the nanotubes are substantially parallel to each other in each
sheet within nanotube sheets 310. In these examples, nanotubes
within nanotube sheets 310 are considered to be substantially
parallel to each other when the combination of those nanotubes with
another sheet of nanotubes forms a nanotube mesh that has
properties meeting various parameters. These parameters may vary
and may include, for example, without limitation, a strength of the
nanotube mesh, flexibility or agility, optical properties,
filtering properties, durability, and conductivity. The particular
parameters used, as well as their values, may vary depending on the
particular implementation.
[0037] Nanotube sheets 310 are also referred to as just sheets, in
these examples. In these examples, a nanotube sheet refers to the
nanotubes in their aligned form. A nanotube sheet may, in some
cases, also be referred to a substrate and/or film on which the
nanotubes are aligned. In other words, a sheet or plane of
nanotubes may be formed from multiple nanotubes that are parallel
to each other.
[0038] Nanotube mesh synthesis system 304 uses nanotube sheets 310
to create nanotube mesh 312. In this example, nanotube mesh
synthesis system 304 includes handling unit 314 and linking unit
316. Handling unit 314 may be used to handle nanotube sheets 310
generated by nanotube alignment system 302. Linking unit 316 is
used to generate links between different sheets of aligned
nanotubes in nanotube sheets 310 to form nanotube mesh 312. In
these examples, nanotube mesh 312 may be preformed from two or more
sheets from nanotube sheets 310. Linking unit 316 may take the form
of an energy source, such as an x-ray, visibile, infra-red, or
ultra-violet light, an electron beam, or a chemical reaction.
Handling unit 314 may be a computer controlled mechanism for
handling nanotube sheets 310. In these examples, nanotube sheets
310 may be located on a fluid or solid film on the substrate
manipulated by handling unit 314.
[0039] In some embodiments, nanotube mesh synthesis system 304
interacts with nanotube alignment system 302 to generate nanotube
mesh 312. For example, nanotube sheets 310 may be returned to
nanotube alignment system 302 to generate additional aligned
nanotubes in a different orientation on the same substrate on which
a sheet from nanotube sheets 310 is found. In this case, nanotube
mesh synthesis system 304 turns or rotates the substrate on which
nanotube sheets 310 are generated with respect to nanotube
alignment system 302 to create another sheet of aligned nanotubes
at an angle from the original set of aligned nanotubes. While
nanotube alignment system 302 creates a second sheet of aligned
nanotubes, nanotube mesh synthesis system 304 may interact by
providing energy through linking unit 316 to link the two sheets of
nanotubes.
[0040] Nanotube mesh synthesis system 304 may use two or more
nanotube sheets to form a nanotube mesh 312. For example, a set of
nanotubes aligned in one direction is placed over or joined with
another set of nanotubes such that the different sheets or lines of
nanotubes meet each other at an angle. As an example, two sheets of
parallel nanotubes may be aligned such that the nanotubes in each
sheet are perpendicular to the nanotubes in the other sheet. Of
course, other angles of alignment may be used other than one that
is substantially perpendicular. Other angles may include, for
example, without limitation, 45 degree angles, 70 degree angles, or
80 degree angles. In some advantageous embodiments, three or four
sheets of nanotubes may be used to form nanotube mesh 312. The
numbers of sheets are described as examples and are not intended to
limit the number of sheets used in this example.
[0041] Nanotube mesh 312 may be used by product manufacturing
system 306 to create product 314. Product manufacturing system 306
may take various forms. For example, product manufacturing system
306 may be a currently used manufacturing system or facility that
is modified to include nanotube meshes as part of the process of
manufacturing the product. In other advantageous embodiments,
product manufacturing system 306 may be specifically designed to
produce product 314 using nanotube mesh 312. Product 314 may take
various forms, including nanotube mesh 312. Nanotube mesh 312 may
be used to manufacture different components of an aircraft. These
components may include, for example, glass used in the aircraft,
coatings for various surfaces on the aircraft, filters for use in
the aircraft, and a coating for the outer surface of the
aircraft.
[0042] Further, nanotube mesh 312 also may be used in various
displays in the aircraft. When used in glass, a nanotube mesh may
distribute any force on the mesh to the edges. As a result, a
material incorporating a nanotube mesh in glass may be capable of
supporting a load while less than around four nanometers thick.
This material may be optically transparent. Further, nanotube mesh
312 may be used as a replacement for normal glass for various
applications such as windows, windshields, and computer screens.
Nanotube mesh 312 has holes and may be permeable to air, water, and
other fluids. If permeability is undesirable, a layer of nanotube
mesh 312 may be coated on one or both sides of a glass pane or even
placed within the glass pane during promotion of this glass. This
type of use of nanotube mesh 312 increases the structural
characteristics.
[0043] Further, nanotube mesh 312 may be used as a coating for
different surfaces of an aircraft. For example, coating the outside
of the aircraft with a nanotube mesh may make repainting the
outside of an aircraft unnecessary for longer periods of times, if
at all.
[0044] In addition to using nanotube mesh 312 to manufacture
aircraft, these types of meshes may be used for other types of
product. For example, nanotube mesh 312 may be used to generate
product 318 in the form of a filter. The filter may be made by
suspending one nanotube mesh at some specified distance above
another nanotube mesh to generate a deconstructive interference.
This deconstructive interference may remove a particular frequency
of light from the spectrum. Further, nanotube mesh 312 also may be
used to enhance the material strength of different substances. For
example, nanotube mesh 312 may be added to a wooden table to reduce
the possibility of scratches.
[0045] Further, nanotube mesh 312 may be used to manufacture rope
that is difficult to break or cut. Also, nanotube mesh 312 may be
used as a non-stick coating for various items, such as non-stick
pots, windows, and floors.
[0046] Additionally, nanotube mesh 312 may be formed into different
shapes. Nanotube mesh 312 is flexible until cured and may be formed
into whatever shape is desired. An object may be coated with
nanotube mesh 312 and cured to provide the desired shape. The mold
around which nanotube mesh 312 is formed may be removed after
nanotube mesh 312 is cured. The result is that a product made of
nanotube meshes may be generated.
[0047] Nanotube mesh 312 may be used to filter particles from air,
liquids, and other gasses. For example, nanotube mesh 312 may be
designed to remove substances, such as, for example, without
limitation, virus and allergens from the air in an aircraft or a
building.
[0048] Nanotube mesh 312 may be used in manufacturing vehicles. For
example, nanotube mesh 312 may be used as a windshield glass
replacement or reinforcement.
[0049] Further, a fiber-glass body of a vehicle may be made
lighter, thinner, and more scratch resistant when coated with
nanotube mesh 312. Further, structural components, such as frame or
unibody of a car, may be made stronger and lighter by incorporating
or using nanotube mesh 312.
[0050] Building materials is another exemplary use of nanotube mesh
312. Nanotube mesh 312 may be used to coat wood or other structural
materials to increase the strength of these materials. Another
example is to incorporate nanotube mesh 312 into steel or concrete
to reinforce these materials without changing the surface.
[0051] Carbon nanotubes have a higher melting point than most
metals, and the melting point is almost as high as that of
tungsten. As a result, nanotube mesh 312 may be a desirable
material for industrial processes that involve the melting or
softening of materials or other high temperature applications.
Another example of a use for nanotube mesh 312 is for incorporation
of various structures in aircraft. Nanotube mesh 312 may be stable
at the temperatures experienced by re-entry into the atmosphere by
a spacecraft. Optical displays may incorporate nanotube mesh 312.
Nanotube mesh 312 may be a transparent conducting material and may
be made as part of transparent circuitry for monitors.
[0052] Nanotube mesh 312 also may be implemented in various
military applications, such as, for example, armor for vehicles and
body armor for soldiers. The permeability of nanotube mesh 312 to
air may make body armor for soldiers more comfortable. As another
example, nanotube mesh 312 may be used within gun barrels to
transfer heat away from the barrel during firing. Further, nanotube
mesh 312 may be used to provide a low friction surface as compared
to current gun barrels. As a result, increased rates of fire may be
possible. Also, nanotube mesh 312 may be used to generate thin
object slices in very thin rigid objects for weaponry. Of course,
many other applications may be possible with nanotube mesh 312, in
addition to those described in these illustrative examples.
[0053] In these examples, the different functional blocks are
provided for the purpose of illustrating different features of the
different advantageous embodiments. This illustration is not meant
to apply architectural limitations in a manner in which different
features may be implemented. For example, components within
nanotube alignment system 302 and nanotube mesh synthesis system
304 may be combined as a single system rather than as two systems.
In other embodiments, features for aligning nanotubes and creating
nanotube meshes may be incorporated within product manufacturing
system 306 as a single system or component.
[0054] With reference now to FIG. 4, a diagram illustrating the
formation of a nanotube mesh is depicted in accordance with an
advantageous embodiment. In this example, sheet 400 and sheet 402
are combined to form nanotube mesh 404. Sheet 400 and sheet 402 are
examples of nanotubes sheets, such as nanotube sheets 310 in FIG.
3. Nanotube mesh 404 is an example of nanotube mesh 312 in FIG.
3.
[0055] In this particular example, sheet 400 is a plurality of
nanotubes aligned substantially parallel to each other. Sheet 402
is another plurality of nanotubes that are also aligned
substantially parallel to each other. In this example, sheet 400 is
aligned with respect to sheet 402 such that nanotubes of sheet 400
are substantially perpendicular to nanotubes in sheet 402. These
two sheets are combined to form nanotube mesh 404.
[0056] The two pluralities of nanotubes in sheet 400 and sheet 402
are attached to each other at a set of points at which the
nanotubes of the different sheets touch each other. The set of
points are one or more points. In these examples, points 406, 408,
410, 412, 414, and 416 are examples of some points in the set of
points for nanotube mesh 404 at which sheets 400 and 402 are linked
to each other. These points may be also referred to as link
points.
[0057] The linking of nanotubes at these points may occur through
bond interactions that occur between the different nanotubes at the
set of points. These bond interactions may be the same atomic bonds
that give carbon nanotubes their structure to form the links
between these nanotubes. In many of the different advantageous
embodiments, atomic bonds are used to link the different nanotubes
to each other. In these illustrative examples, these links are
cross links that may have approximately the same strength as a
nanotube. These cross links, however, may be subject to torques
that may cause a deformation or rotation of one nanotube with
respect to another.
[0058] The number of cross links formed between sheets 400 and 402
may define a property of nanotube mesh 404, such as the rigidity of
nanotube mesh 404. As more cross links are present, the mesh
becomes more rigid or harder. The formation of the cross links at
the set of points is also referred to as "curing". As more cross
links are formed between the different sets of points, the tensile
strength of nanotube mesh 404 approaches that of an individual
nanotube.
[0059] These different cross links may be made through applying
energy to nanotube mesh 404. This energy may be applied through an
energy source within nanotube mesh synthesis system 304 in FIG. 3.
In particular, linking unit 316, within nanotube mesh synthesis
system 304 in FIG. 3, may provide the energy used to create links
or bonds. For example, x-ray energy may be applied to nanotube mesh
404 to create cross links at the set of points.
[0060] The amount of x-ray energy may define how many cross links
are formed at the set of points. These cross links may take the
form of a covalent bond or a sharing of carbon items, which is a
specific type of covalent bond. Further, other non-covalent bonds
may be used. For example, a Van der Waals bond is an example of a
non-covalent bond that may be used to attach or link sheet 400 to
sheet 402. This type of bond does not require the introduction or
application of energy from an energy source.
[0061] Sheet 400 and sheet 402 may be constructed using a number of
different mechanisms. The alignment of nanotubes to form sheet 400
and sheet 402 may be achieved through a number of different
methods. These methods include, for example, without limitation,
magnetic alignment and rotating and pulling. Magnetic alignment
includes exposing nanotubes to a magnetic field that is
sufficiently strong to cause the nanotubes to align in a
substantially parallel manner. The rotating and pulling method
makes sheets of aligned nanotubes rolled out of a forest of
nanotubes. In this type of method, touching a substrate to a free
end of a forest of nanotubes and pulling the surface away from the
forest of nanotubes may produce a sheet of aligned nanotubes.
[0062] In these examples, a fluid method is disclosed in the
advantageous embodiments. This fluid method is one presented by the
different advantageous embodiments for use in aligning nanotubes,
in addition to currently known methods as described above. In one
advantageous embodiment, a fluid method is used for aligning
nanotubes. Nanotubes are dispersed on the surface of a solution.
This embodiment may require nanotubes to be in the solution to form
dispersed nanotubes. A substrate with a surface is placed into the
solution in which the surface is at an angle relative to a surface
of the solution. The substrate is removed from the solution at an
angle and at a rate sufficient to apply a velocity gradient to the
nanotubes such that the nanotubes align in a direction that is
substantially parallel to the direction of motion to form aligned
nanotubes. FIGS. 5-9 illustrate steps used to align nanotubes in a
fluid method as disclosed by the advantageous embodiments.
[0063] With reference now to FIG. 5, a top view of an apparatus in
a nanotube alignment system is depicted in accordance with an
advantageous embodiment. In this example, alignment device 500
includes tank 502 and surface arms 504 and 506. In this example,
alignment device 500 is an example of a device that may be found in
nanotube alignment system 302 in FIG. 3. Surface arms 504 and 506
may be moveable in a manner to change the surface area of solution
508 within tank 502. In these examples, surface arms 504 and 506
may be moveable through a computer controlled mechanism.
[0064] In these different examples, alignment device 500 may be
implemented using a commercially available device, such as, for
example, a Langmuir Blodgett apparatus. An example of such a device
is a KSV2000 series Langmuir Blodgett apparatus, which is available
from Scientific Solutions SA. This type of device is currently used
for other purposes, such as measuring surface tensions.
[0065] In the different advantageous embodiments, this type of
device may be used to align nanotubes 510 dispersed on the surface
of solution 508. In these examples, nanotubes 510 are dispersed in
a manner such that they float near the surface, based on surface
tension with respect to solution 508.
[0066] The type of solution used may vary, depending on the
particular implementation. Any solution may be used that may
provide a surface tension for holding nanotubes in a manner that
allows those nanotubes to be aligned as the surface area changes.
In these examples, solution 508 may be, for example, a aqueous
surfactant solution, such as a soap solution. In these examples,
the surfactant may be a non-ionic surfactant, such as stearic acid,
stearyl alcohol, Triton.RTM.-X 100, or Brij.RTM. 98. Triton.RTM.-X
100 is a registered trademark of Union Carbide Chemicals and
Plastics Co. Inc., and Brij.RTM. 98 is a registered trademark of
ICI Americas, Inc.
[0067] Turning now to FIG. 6, a diagram illustrating the
pre-alignment of nanotubes in an apparatus in a nanotube alignment
system is depicted in accordance with an advantageous embodiment.
In this illustration, surface arms 504 and 506 have been moved
towards each other along the direction of arrows 600 and 602. By
moving surface arms 504 and 506 in these directions, nanotubes 510
orient in a similar direction such that they become substantially
parallel to each other. This process may pre-align nanotubes 510
prior to forming a layer or sheet of nanotubes from nanotubes
510.
[0068] In the different examples, nanotubes 510 may take various
forms. For example, nanotubes 510 may be single-wall or multi-wall
nanotubes. These nanotubes also may be carbon nanotubes or may be
made from other types of materials. One example of a non-carbon
nanotube is galliun nitride. Further, nanotubes 510 may be any
chirality. In other words, nanotubes 510 may be semiconductor or
metallic in nature, depending on the particular implementation.
[0069] FIG. 7 provides a cross-sectional view of an alignment
device. In this example, nanotubes 510 are oriented in a manner
such that they are parallel to each other within solution 508 in
tank 502.
[0070] With reference now to FIG. 8, a diagram illustrating the
aligning of nanotubes on a substrate is depicted in accordance with
an advantageous embodiment. In this example, substrate 800 has been
introduced into solution 508 and is withdrawn such that portion 802
of nanotubes 510 adhere to substrate 800 and align the nanotubes to
form a sheet of nanotubes. The nanotubes in this sheet are aligned
in the direction approximately parallel to each other. This sheet
of nanotubes may have a length, a width, and a thickness of at
least the dimension of a single nanotube, in these examples. Of
course, the actual dimension of a sheet of nanotubes may vary,
depending on the size of substrate 800.
[0071] Substrate 800 may take various forms. For example, substrate
800 may be any material from which a sheet of nanotubes may be
formed by drawing substrate 800 out of solution 508. In these
examples, substrate 800 may be, for example, without limitation,
amorphous silicon dioxide.
[0072] The aligned nanotubes are substantially parallel to each
other, in these examples. Substrate 800 is removed from solution
508 at an angle and at a rate sufficient to apply velocity to
nanotubes 510 such that portion 802 of nanotubes 510 adhere to the
surface of substrate 800 in a direction that is substantially
parallel to the surface to form aligned nanotubes. The rate at
which substrate 800 is withdrawn from solution 508 may vary,
depending on the particular implementation. In this example, the
rate is 1.times.10.sup.-2 m/s. The operating condition for creating
a sheet of nanotubes, in these examples, is at ambient temperature
and pressure. Alignment device 500 may be mounted on a vibration
damped workbench to reduce or eliminate vibrations.
[0073] Turning now to FIG. 9, a more detailed diagram illustrating
the aligning of nanotubes on a substrate is depicted in accordance
with an advantageous embodiment. In this example, substrate 900 is
shown as being drawn out of solution 902 in which nanotubes, such
as nanotubes 904, 906, 908, 910, 912, and 914 are located on the
surface of solution 902. In these examples, solution 902 is an
example of a solution in an alignment apparatus, such as alignment
apparatus 500 in FIG. 5.
[0074] By drawing substrate 900 out of solution 902 at a selected
velocity, nanotubes, such as nanotubes 910, 912, and 914 are
aligned on substrate 900. In these examples, only a cross-section
of substrate 900 is illustrated. Other nanotubes located parallel
to nanotubes 904, 906, 908, 910, 912, and 914 are present, but not
seen in this view. These nanotubes also are drawn up and aligned on
substrate 900 in a substantially parallel direction to the
illustrated nanotubes.
[0075] In these examples, the alignment of these nanotubes on
substrate 900 is not performed directly on surface 916 of substrate
900. Instead, the alignment of these nanotubes on substrate 900 is
on a film at section 918 formed from solution 902 that adheres to
surface 916 of substrate 900.
[0076] Nanotubes, such as nanotubes 904, 906, and 908 are drawn
towards surface 916 of substrate 900 through the movement of
substrate 900 along direction 920 out of solution 902. Arrow 922
illustrates the motion of solution 902 as substrate 900 is being
moved out of solution 902. Arrow 922 illustrates a velocity
gradient that is sufficient to cause the nanotubes in solution 902
to align in the direction of motion of substrate 900. After
substrate 900 has been moved out of solution 902, forming a first
sheet of nanotubes, a second sheet of nanotubes may be formed on
substrate 900.
[0077] Solution 902 is present on both sides of substrate 900. In
this example, only the solutions shown on the side of surface 916
is depicted for purposes of illustrating the manner in which
nanotubes are aligned to form a sheet of nanotubes on substrate
900. Further, substrate 900 is shown as being drawn out of solution
902 at an angle of around ninety degrees. Other angles may be used,
depending on the particular implementation.
[0078] With reference now to FIG. 10, a diagram illustrating the
creation of a second sheet of nanotubes is depicted in accordance
with an advantageous embodiment. After substrate 900 is withdrawn
from solution 902 as illustrated in FIG. 9, substrate 900 may be
rotated around 90 degrees and reintroduced into solution 902 at
around the same angle. The rotation of substrate 900 by 90 degrees
is performed to create a second layer or sheet of nanotubes that is
positioned substantially perpendicular to the first sheet of
nanotubes.
[0079] In this example, substrate 900 is moved in direction 1000
into solution 902. As illustrated, the downward movement of
substrate 900 into solution 902 causes fluid instability line 1002.
In this example, fluid to the left of fluid instability line 1002
is part of film 1003 on substrate 900 that was previously formed
from withdrawing substrate 900 from a solution. In these examples,
the solution may be solution 902, or solution from another
container, depending on the particular embodiment.
[0080] Solution 902 moves along the direction of arrows 1004 to
include instability point 1006. Thereafter, solution 902 moves
downward along the direction of arrows 1008 along fluid instability
line 1002. Solution from the film on substrate 900 moves along the
direction of arrows 1012 and 1014. As can be seen, in this example,
neck 1016 is present on film 1003 in section 1010.
[0081] Nanotubes on the surface of solution 902 are aligned by the
sharp velocity gradient at instability point 1006. As a result, the
nanotubes line up perpendicular to the nanotubes already on film
1003 of substrate 900.
[0082] In this example, nanotubes 1018 and 1020 are still located
on solution 902. Nanotubes 1022, 1024, and 1026 are aligned along
fluid instability line 1002 in an orientation that is about
perpendicular to nanotubes 904, 906, 908, 910, 912, and 914. The
orientation also may be described as about or substantially
parallel to a direction of motion of substrate 900, which is shown
by arrow 1000. In this example, nanotubes 1022, 1024, and 1026
contact nanotubes 904, 906, 908, 910, and 912 at a set of points.
Nanotubes 1028, 1030, and 1032 are nanotubes also previously
aligned, but not shown in FIG. 9. These nanotubes are located in
section 1010. In other examples, some nanotubes may not contact
others. A set of links between the nanotubes at this set of points
may be made to form a nanotube mesh, such as nanotube mesh 404 in
FIG. 4.
[0083] The application of x-rays or x-ray energy below instability
point 1006, in these examples, may cause a formation of the
nanotube mesh. The application of the x-ray energy may cause a set
of points at which nanotubes from the first sheet contact nanotubes
in the second sheet to be linked to each other. The amount of x-ray
energy may change the number of links that are formed between
nanotubes and the two different sheets at the set of points. Some
points in the set of points may not have links formed, depending on
the amount of x-ray energy applied.
[0084] With reference now to FIG. 11, a flowchart of a process for
aligning nanotubes is depicted in accordance with an advantageous
embodiment. The process illustrated in FIG. 11 may be performed
using a nanotube alignment system, such as alignment device 500 in
FIG. 5. As a specific example, alignment device 500 in FIG. 5 may
be used to perform the alignment of nanotubes with respect to a
substrate.
[0085] The process begins by dispersing nanotubes onto the surface
of a solution (operation 1100). Thereafter, the substrate is moved
in the solution at an angle and at a rate sufficient to apply
velocity gradient to the nanotubes on the surface of the solution
to align the nanotubes in a direction substantially parallel to the
direction of motion of the surface (operation 1102). Operation 1102
may be performed by moving the substrate out of the solution. In
addition, operation 1102 also may be performed by moving the
substrate into the solution, depending on the particular
implementation. The movement of the substrate into the solution may
be performed using nanotube alignment system 302 and/or nanotube
mesh synthesis system 304 in FIG. 3.
[0086] With reference now to FIG. 12, a flowchart of a process for
manufacturing nanotube mesh is depicted in accordance with an
advantageous embodiment. The process illustrated in FIG. 12 may be
implemented using manufacturing environment 300 in FIG. 3.
[0087] The process begins by forming a first layer of nanotubes
(operation 1200). Thereafter, a second layer of nanotubes is formed
(operation 1202). The first layer of nanotubes is overlaid with the
second layer nanotubes (operation 1204). The process then forms a
set of points at which the first layer connects to the second layer
(operation 1206), with the process terminating thereafter.
[0088] Operations 1200 and 1202 may be performed using a process,
such as the process illustrated in FIG. 11 above to align
nanotubes. Depending on the embodiment, the first layer of
nanotubes may be overlaid with the second layer of nanotubes while
the second layer of nanotubes is formed.
[0089] Thus, the different advantageous embodiments provide a
nanotube mesh and a method for manufacturing nanotube meshes, which
include aligning nanotubes to create sheets of aligned nanotubes.
In one advantageous embodiment, an apparatus has a first sheet and
a second sheet. The first sheet has first nanotubes aligned in a
direction approximately parallel to each other. The second sheet
has second nanotubes aligned in a direction approximately to each
other, wherein the first layer is attached to the second layer at
set of points at which the first nanotubes contact the second
nanotubes to form a nanotube mesh.
[0090] A method is used for aligning nanotubes in one advantageous
embodiment. Nanotubes are dispersed on the surface of a solution to
form a plurality of dispersed nanotubes. A substrate with a surface
is placed into the solution in which the surface is at an angle
relative to a surface of the solution. The substrate is removed
from the solution at an angle and at a rate sufficient to apply a
velocity gradient to the nanotubes such that the nanotubes align in
a direction that is substantially parallel to the direction of
motion to form aligned nanotubes.
[0091] The description of the present invention has been presented
for purposes of illustration and description, and is not intended
to be exhaustive or limited to the invention in the form disclosed.
Many modifications and variations will be apparent to those of
ordinary skill in the art. Further, different advantageous
embodiments may provide different advantages as compared to other
advantageous embodiments. For example, although many of the
illustrative examples are directed towards components for aircraft,
the processes used to align nanotubes and to create nanotube meshes
may be used in conjunction with other types of products.
[0092] The different advantageous embodiments may be applied to
products, such as, for example, furniture, automobiles, spacecraft,
fire arms, and glass products. The aligning process may also be
used to generate aligned sheets made of multiple materials, when
sheets 400 and 402 are aligned in the same direction and are made
of materials that otherwise would not be parallel to each other
when mixed, such as two types of fatty acids that would coagulate
or react when mixed.
[0093] The embodiment or embodiments selected are chosen and
described in order to best explain the principles of the invention,
the practical application, and to enable others of ordinary skill
in the art to understand the invention for various embodiments with
various modifications as are suited to the particular use
contemplated.
* * * * *