# US 12,215,206 B2 · Low-defect fabrication of composite materials > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,215,206 B2 - Document ID: US12215206B2 - Status: Granted - Kind: B2 - Application number: 18/448,894 - Filed: 2023-08-11 - Published: 2024-04-11 - Granted: 2025-02-04 - Earliest claimed: 2017-09-15 - Assignees: Massachusetts Institute of Technology - Applicants: Massachusetts Institute of Technology - Inventors: Jeonyoon Lee; Brian L. Wardle; Diana Jean Lewis - Web page: https://patentgrep.com/patent/US12215206B2 ## CPC - C08J 5/005: {Reinforced macromolecular compounds with nanosized materials, e.g. nanoparticles, nanofibres, nanotubes, nanowires, nanorods or nanolayered materials} - C01B 32/15: Nano-sized carbon materials - C01B 32/16: Preparation - C08J 5/249: {characterised by the additives used in the prepolymer mixture} - C01B 2202/08: Aligned nanotubes - C08J 2363/00: Characterised by the use of epoxy resins; Derivatives of epoxy resins - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C} ## Abstract Methods and systems for the fabrication of composite materials are generally described. Certain inventive methods and systems can be used to fabricate composite materials with few or no defects. According to certain embodiments, composite materials are fabricated without the use of an autoclave. In some embodiments, composite materials are fabricated in low pressure environments. ## Claims ### Claim 1 A method of forming a composite article, comprising: heating a first substrate and/or a second substrate out of an autoclave such that at least a portion of the first substrate and/or at least a portion of the second substrate softens and/or melts and a forest of elongated nanostructures between the first substrate and the second substrate becomes at least partially embedded within the first substrate and/or the second substrate via capillary action to form the composite article comprising the first substrate, the second substrate, and the forest of elongated nanostructures; wherein: the forest of elongated nanostructures has a height; the forest of elongated nanostructures has a first dimension that is substantially perpendicular to the height of the forest, the first dimension being at least 100 times greater than the height of the forest; the forest of elongated nanostructures has a second dimension that is substantially perpendicular to the height of the forest and substantially perpendicular to the first dimension, the second dimension being at least 100 times greater than the height of the forest; and after the heating, the percentage of an interlaminar region of the composite article occupied by voids is less than or equal to 1%. ### Claim 2 (depends on 1) The method of claim 1, wherein heating the first substrate and/or the second substrate comprises moving a source of the heat laterally across the first substrate and/or the second substrate. ### Claim 3 (depends on 1) The method of claim 1, wherein the forest of elongated nanostructures comprises carbon-based nanostructures. ### Claim 4 (depends on 1) The method of claim 1, wherein the forest of elongated nanostructures comprises carbon nanotubes. ### Claim 5 (depends on 1) The method of claim 1, wherein the forest of elongated nanostructures has a number average nearest neighbor distance of less than or equal to 100 nm. ### Claim 6 (depends on 1) The method of claim 1, wherein the forest of elongated nanostructures has a number average nearest neighbor distance of greater than or equal to 1 nm. ### Claim 7 (depends on 1) The method of claim 1, wherein the forest of elongated nanostructures has a volume fraction of nanostructures of greater than or equal to 0.001. ### Claim 8 (depends on 1) The method of claim 1, wherein the forest of elongated nanostructures has a volume fraction of nanostructures of less than or equal to 0.8. ### Claim 9 (depends on 1) The method of claim 1, wherein at least a portion of the elongated nanostructures comprise carbon, silicon, indium-gallium-arsenide materials, boron nitride, silicon nitride, silicon carbide, dichalcogenides, oxides, boron-carbon-nitrogen compounds, and/or polymers. ### Claim 10 (depends on 1) The method of claim 1, wherein the composite article has at least 10% less void volume than would be present if no forest of elongated nanostructures were arranged between the first substrate and the second substrate but the processing conditions were otherwise identical. ### Claim 11 (depends on 1) The method of claim 1, wherein the first substrate comprises a prepreg. ### Claim 12 (depends on 11) The method of claim 11, wherein the second substrate comprises a prepreg. ### Claim 13 (depends on 11) The method of claim 11, wherein the prepreg is an autoclave prepreg. ### Claim 14 A method of forming a composite article, comprising: heating a first substrate and/or a second substrate while the first substrate and/or the second substrate is in an environment having a pressure of less than 3 bar absolute, such that at least a portion of the first substrate and/or at least a portion of the second substrate softens and/or melts and a forest of elongated nanostructures between the first substrate and the second substrate becomes at least partially embedded within the first substrate and/or the second substrate via capillary action to form the composite article comprising the first substrate, the second substrate, and the forest of elongated nanostructures; wherein: the forest of elongated nanostructures has a height; the forest of elongated nanostructures has a first dimension that is substantially perpendicular to the height of the forest, the first dimension being at least 100 times greater than the height of the forest; the forest of elongated nanostructures has a second dimension that is substantially perpendicular to the height of the forest and substantially perpendicular to the first dimension, the second dimension being at least 100 times greater than the height of the forest; and after the heating, the percentage of an interlaminar region of the composite article occupied by voids is less than or equal to 1%. ### Claim 15 (depends on 14) The method of claim 14, wherein the first substrate comprises a prepreg. ### Claim 16 (depends on 15) The method of claim 15, wherein the second substrate comprises a prepreg. ### Claim 17 (depends on 15) The method of claim 15, wherein the prepreg is an autoclave prepreg. ### Claim 18 (depends on 17) The method of claim 17, wherein at least a portion of the heating does not take place within an autoclave.