# US 10,873,026 B2 · Alignment of carbon nanotubes in confined channels > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,873,026 B2 - Document ID: US10873026B2 - Status: Granted - Kind: B2 - Application number: 15/455,587 - Filed: 2017-03-10 - Published: 2018-09-13 - Granted: 2020-12-22 - Earliest claimed: 2017-03-10 - Assignees: Wisconsin Alumni Research Foundation - Applicants: Wisconsin Alumni Research Foundation - Inventors: Michael Scott Arnold; Katherine Rose Jinkins; Gerald Joseph Brady; Padma Gopalan - Web page: https://patentgrep.com/patent/US10873026B2 ## CPC - H10K 71/12: using liquid deposition, e.g. spin coating - C01B 32/168: After-treatment - C01B 32/172: Sorting - H10K 71/191: {characterised by provisions for the orientation or alignment of the layer to be deposited} - H10K 85/221: {Carbon nanotubes} - B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic - B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites - B82Y 40/00: Manufacture or treatment of nanostructures - C01B 2202/08: Aligned nanotubes - H10K 10/484: {characterised by the channel regions} - Y10S 977/746: Modified with biological, organic, or hydrocarbon material - Y10S 977/847: Surface modifications, e.g. functionalization, coating - Y10S 977/891: Vapor phase deposition - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES - C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C} - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract Methods for forming carbon nanotube arrays are provided. Also provided are the arrays formed by the methods and electronic devices that incorporate the array as active layers. The arrays are formed by flowing a fluid suspension of carbon nanotubes through a confined channel under conditions that create a velocity gradient across the flowing suspension. ## Claims ### Claim 1 A method of forming a carbon nanotube array, the method comprising: creating a shear flow of a fluid suspension of organic material-coated carbon nanotubes through a flow channel, wherein the flow channel is defined by a deposition substrate comprising a first material and a confining wall comprising a second material, wherein a velocity gradient is formed across the flowing fluid suspension and further wherein the flowing fluid suspension passes over the deposition substrate and exits the flow channel; depositing organic material-coated carbon nanotubes from the fluid suspension onto the deposition substrate to form a film of carbon nanotubes on the deposition substrate, wherein: the deposited organic material-coated carbon nanotubes in the film are aligned along the direction of shear flow; the film is formed while the fluid suspension is flowing over the deposition substrate; and the organic material-coated carbon nanotubes are aligned and deposited on the deposition substrate without the use of an energized electrode pair. ### Claim 2 (depends on 1) The method of claim 1, wherein the organic material coated carbon nanotubes consist essentially of semiconducting single-walled polymer coated carbon nanotubes. ### Claim 3 (depends on 1) The method of claim 1, wherein the velocity gradient has a magnitude of at least 900 mm/s/mm. ### Claim 4 (depends on 1) The method of claim 1, wherein the organic material-coated carbon nanotubes have lengths of no greater than 1 μm. ### Claim 5 (depends on 1) The method of claim 1, further comprising removing the organic material from the deposited organic material-coated carbon nanotubes. ### Claim 6 (depends on 1) The method of claim 1, wherein the flow channel is a closed channel. ### Claim 7 (depends on 6) The method of claim 6, wherein the fluid suspension of organic material-coated carbon nanotubes flows at a rate that is greater than the rotational diffusion coefficients of the carbon nanotubes in the fluid suspension and the flow channel has a width of at least 500 μm. ### Claim 8 (depends on 6) The method of claim 6, wherein the fluid suspension of organic material-coated carbon nanotubes flows at a rate that is at least twice as large as the rotational diffusion coefficients of the carbon nanotubes in the fluid suspension and the velocity gradient has a magnitude of at least 900 mm/s/mm. ### Claim 9 A method of forming a carbon nanotube array, the method comprising: creating a shear flow of a fluid suspension of organic material-coated carbon nanotubes through a closed flow channel that is defined by a deposition substrate comprising a first material and a confining wall comprising a second material, wherein a velocity gradient is formed across the flowing fluid suspension; flowing a liquid that is immiscible with the fluid suspension through the closed flow channel along with the fluid suspension, wherein the fluid suspension and the liquid flow side-by-side and the organic material-coated carbon nanotubes are concentrated at the interface between the fluid suspension and the liquid, relative to their concentration in the bulk of the fluid suspension, and are aligned parallel with the interface; and depositing organic material-coated carbon nanotubes from the interface onto the deposition substrate, wherein the deposited organic material-coated carbon nanotubes are aligned along the direction of shear flow. ### Claim 10 (depends on 9) The method of claim 9, wherein the liquid is water. ### Claim 11 (depends on 9) The method of claim 9, further comprising translating the interface between the fluid suspension and the liquid across the deposition substrate. ### Claim 12 (depends on 9) The method of claim 9, further comprising flowing a solvent through the flow channel along with the fluid suspension and the liquid, wherein the fluid suspension flows between the liquid and the solvent. ### Claim 13 A method of forming a carbon nanotube array, the method comprising: creating a shear flow of a fluid suspension of organic material-coated carbon nanotubes through a flow channel, wherein the flow channel is defined by: a deposition substrate comprising a first material; the confining wall comprising a second material, which is disposed opposite and facing the deposition substrate; and a floor comprising a layer of a liquid that is immiscible with the fluid suspension and is disposed between the deposition substrate and the confining wall, wherein a velocity gradient is formed across the flowing fluid suspension; and depositing organic material-coated carbon nanotubes from the fluid suspension onto the deposition substrate during the shear flow of the fluid suspension of the organic-material-coated nanotubes through the flow channel, wherein the deposited organic material-coated carbon nanotubes are aligned along the direction of shear flow. ### Claim 14 (depends on 13) The method of claim 13, wherein creating a shear flow of the fluid suspension of organic material-coated carbon nanotubes through the flow channel comprises flowing the fluid suspension of organic material-coated carbon nanotubes on the layer of the liquid. ### Claim 15 (depends on 13) The method of claim 13, wherein the liquid that is immiscible with the fluid suspension is water. ### Claim 16 (depends on 14) The method of claim 14, further comprising translating the fluid suspension of organic material-coated carbon nanotubes across the deposition substrate as it is flowing through the flow channel. ### Claim 17 (depends on 14) The method of claim 14, wherein creating a shear flow of the fluid suspension of organic material-coated carbon nanotubes through the flow channel further comprises flowing the layer of the liquid in the same direction as the fluid suspension of organic material-coated carbon nanotubes. ### Claim 18 (depends on 17) The method of claim 17, further comprising changing the volumetric flow rate of the fluid suspension of organic material-coated carbon nanotubes relative to the volumetric flow rate of the layer of liquid, such that an interface formed by the layer of liquid and the fluid suspension translates along the deposition substrate. ### Claim 19 A method of forming a carbon nanotube array, the method comprising: creating a shear flow of a fluid suspension of organic material-coated carbon nanotubes through a flow channel, wherein a velocity gradient is formed across the flowing fluid suspension, the flow channel being defined by a deposition substrate comprising a first material and a confining wall comprising a second material and having a channel width of at least 500 μm; and depositing organic material-coated carbon nanotubes from the fluid suspension onto the deposition substrate while the fluid suspension is flowing through the flow channel, wherein: the deposited organic material-coated carbon nanotubes in the film are aligned along the direction of shear flow; the film is formed while the fluid suspension is flowing over the deposition substrate; and the organic material-coated carbon nanotubes are aligned and deposited on the deposition substrate without the use of an energized electrode pair. ### Claim 20 (depends on 19) The method of claim 19, wherein the flow channel has a channel height in the range from 0.5 mm to 5 mm. ### Claim 21 (depends on 9) The method of claim 9, wherein the organic material-coated carbon nanotubes from the interface are deposited onto the deposition substrate while the fluid suspension and the liquid flow side-by-side.