IP Library › Granted Patent US 12,649,835
Granted Patent B2
US 12,649,835 · App. 18/169,722 · Granted Jun 9, 2026

Ultrastrong aerogels based on aramid nanofiber composites and membrane devices made therefrom

Inventors: Lizhi Xu (Changsha, CN); Hegeng Li (Wuhan, CN); Hongzhen Liu (Shenzhen, CN); Huimin He (Kaihua, CN); Zuochen Wang (Langzhou, CN)
Assignees: VERSITECH LIMITED; Advanced Biomedical Instrumental Centre Limited
C08J9/0061C08J9/28C08J2201/0502C08J2205/044C08J2205/10C08J2329/04C08J2377/10C08J2429/04C08J2477/10H10W20/01
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Quick Facts
Patent No.
US 12,649,835
App. No.
18/169,722
Granted
Jun 9, 2026
Kind
B2
Abstract

A composite nanofiber aerogel (CNA) is formed from aramid nanofibers (ANFs) combined with polyvinyl alcohol (PVA). These nanoscale constituents of the aerogel form 3D networks with high nodal connectivity and strongly welded connectivity joints between fibrils so that the structure has high stiffness and strength compared to other polymeric aerogels and successive breakage of crosslinks at the connectivity nodes affords energy dissipation while maintaining the overall structural integrity. A specific class of CNA with a specific solid content may be used to form a thin firm with a composite nanofiber framework (CNFF) that is useful in the manufacture of kirigami wearable electronics.

Claims (21)

1 . A composite nanofiber aerogel (CNA) comprising aramid nanofibers (ANFs) combined with polyvinyl alcohol (PVA),

wherein the composite nanofiber aerogel is created by

forming a dispersion of about 3% wt of the ANFs dissolved in dimethyl sulfoxide (DMSO) in about 7 days,

forming a dispersion of about 15% wt of the PVA dissolved in the DMSO in about 7 days,

mixing the ANF dispersion with the PVA dispersion in a mass ratio of 1:1 to form a precursor liquid,

conducting a solvent exchange in deionized (DI) water leading to solid hydrogels and immersing the hydrogels in ethanol for about another 24 hours, and

conducting critical point drying (CPD), whereby a solid foam aerogel with nanoscale porosity is formed, and

wherein nanoscale constituents of the aerogel form 3D networks with nodal connectivity and welded connectivity nodal joints between fibrils so that the aerogel has a fracture energy of about 4,697 Jm −2 , a 76% porosity and a toughness of about 1,050 kJ/m 3 and wherein successive breakage of crosslinks at the connectivity nodal joints affords energy dissipation while maintaining the overall structural integrity.

2 . The composite nanofiber aerogel according to claim 1 wherein average pore sizes of the CNA range from 140 nm to 1,463 nm and can be adjusted by adjusting a solid content of the composite nanofiber aerogel.

3 . The composite nanofiber aerogel according to claim 1 wherein air permeability with a thickness of ˜20 μm results in a pressure drop of 0.9-2.2 kPa under a face velocity of 0.05 ms −1 .

4 . A method for forming a composite nanofiber aerogel (CNA) comprising the steps of:

forming a dispersion of about 3% wt of aramid nanofibers (ANFs) in dimethyl sulfoxide (DMSO) in about 7 days,

forming a dispersion of about 15% wt of polyvinyl alcohol (PVA) dissolved in the DMSO in about 7 days;

mixing the ANF-DMSO dispersion with the PVA in the DMSO dispersion to form a precursor liquid, wherein the mixing of the ANF-DMSO dispersion with the dissolved PVA in the DMSO dispersion was in a 1:1 mass ratio,

conducting a solvent exchange in deionized (DI) water leading to solid hydrogels and immersing the hydrogels in ethanol for about another 24 hours, and

conducting critical point drying (CPD), whereby a solid foam aerogel with nanoscale porosity is formed, wherein the solid foam aerogel is having a fracture energy of about 4,697 Jm −2 , a 76% porosity and a toughness of about 1,050 kJ/m 3 .

5 . The method of claim 4 further including the step of casting the liquid precursor into a 3D mold to yield a bulk aerogel sample.

6 . The method of claim 4 further including the step of spin-coating or doctor-blading the liquid precursor to generate aerogel films.

7 . The method of claim 5 further including the step of ablating the aerogel with an infrared laser to machine the aerogel sample at millimeter scale.

8 . The method of claim 6 further including the step of ablating the aerogel with an infrared laser to machine the aerogel film at millimeter scale.

9 . The method of claim 4 wherein the aramid nanofibers are Kevlar para aramid pulp, both steps of forming the dispersions were achieved under magnetic stirring at 95° C.

Assignments (3)
CHANGE OF NAME Recorded May 1, 2026
From: VERSITECH LIMITED
To: UNIVERSITY OF HONG KONG VERSITECH LIMITED
Reel/Frame 075506/0542 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 14, 2023
From: XU, LIZHI; LI, HEGENG; LIU, HONGZHEN; HE, HUIMIN; WANG, ZUOCHEN
To: THE UNIVERSITY OF HONG KONG; ADVANCED BIOMEDICAL INSTRUMENTATION CENTRE LIMITED
Reel/Frame 063328/0226 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 14, 2023
From: THE UNIVERSITY OF HONG KONG
To: VERSITECH LIMITED
Reel/Frame 063328/0481 →
Continuity (1)
Related Publication 20240270916A1 · Aug 15, 2024
References Cited (75)
US 6238837B1 · Fan · 2001 [cited by examiner]
US 20090184088A1 · Carlson · 2009 [cited by examiner]
US 20190085139A1 · Kotov · 2019 [cited by examiner]
US 20190390025A1 · Sakaguchi · 2019 [cited by examiner]
CN110776654 original (Year: 2020). [cited by examiner]
CN110776654 translation (Year: 2020). [cited by examiner]
CN114633468 original (Year: 2022). [cited by examiner]
CN114633468 translation (Year: 2022). [cited by examiner]
Zhang, X., Vyatskikh, A., Gao, H. J., Greer, J. R. & Li, X. Y., Lightweight, flaw-tolerant, and ultrastrong nano-architected carbon. PNAS 116, pp. 6665-6672 (2019). [cited by applicant]
Bauer, J. et al., Nanolattices: An emerging class of mechanical metamaterials. Adv. Mater. 29, 1703343, pp. 1-89 (2017). [cited by applicant]
Zheng, X. Y. et al., Ultralight, ultra-stiff mechanical metamaterials. Science 344, pp. 1373-1377 (2014). [cited by applicant]
Zhao, S. Y. et al., Additive manufacturing of silica aerogels. Nature 584, pp. 387-392 (2020). [cited by applicant]
Danks, A. E., Hall, S. R. & Schnepp, Z., The evolution of ‘sol-gel’ chemistry as a technique for materials synthesis. Mater. Horiz. 3, pp. 91-112 (2016). [cited by applicant]
Owens, G. J. et al., Sol-gel based materials for biomedical applications. Prog. Mater. Sci. 77, pp. 1-79 (2016). [cited by applicant]
Xue, J. J., Wu, T., Dai, Y. Q. & Xia, Y. N., Electrospinning and electrospun nanofibers: Methods, materials, and applications. Chem. Rev. 119, 5298-5415 (2019). [cited by applicant]
Ding, Y. C., Hou, H. Q., Zhao, Y., Zhu, Z. T. & Fong, H., Electrospun polyimide nanofibers and their applications. Prog. Polym. Sci. 61, pp. 67-103 (2016). [cited by applicant]
Qian, Z. C., Wang, Z., Zhao, N. & Xu, J., Aerogels derived from polymer nanofibers and their applications. Macromol. Rapid Commun. 39, 1700724, pp. 1-16 (2018). [cited by applicant]
Zhao, X. H. et al., Soft materials by design: Unconventional polymer networks give extreme properties. Chem. Rev. 121, pp. 4309-4372 (2021). [cited by applicant]
Zhao, S. Y., Malfait, W. J., Guerrero-Alburquerque, N., Koebel, M. M. & Nystrom, G., Biopolymer aerogels and foams: chemistry, properties, and applications. Angew. Chem. Int Ed. 57, pp. 7580-7608 (2018). [cited by applicant]
Budtova, T., Cellulose Il aerogels: a review. Cellulose 26, pp. 81-121 (2019). [cited by applicant]
Song, J. W. et al., Highly compressible, anisotropic aerogel with aligned cellulose nanofibers. ACS Nano 12, pp. 140-147 (2018). [cited by applicant]
Heise, K. et al., Nanocellulose: Recent fundamental advances and emerging biological and biomimicking applications. Adv. Mater. 33, pp. 2004349, pp. 1-30 (2021). [cited by applicant]
Takeshita, S. et al., Formation of nanofibrous structure in biopolymer aerogel during supercritical CO2 processing: the case of chitosan aerogel, Biomacromolecules 20, pp. 2051-2057 (2019). [cited by applicant]
Wei, S., Ching, Y. C. & Chuah, C. H., Synthesis of chitosan aerogels as promising carriers for drug delivery: a review. Carbohydr. Polym. 231, 115744, pp. 1-14 (2020). [cited by applicant]
Duan, B., Huang, Y., Lu, A. & Zhang, L. N., Recent advances in chitin based materials constructed via physical methods. Prog. Polym. Sci. 82, pp. 1-33 (2018). [cited by applicant]
Qin, Y. Y. et al., Lightweight, super elastic, and mechanically flexible graphene/polyimide nanocomposite foam for strain sensor application. ACS Nano 9, pp. 8933-8941 (2015). [cited by applicant]
Meador, M. A. B. et al., Mechanically strong, flexible polyimide aerogels crosslinked with aromatic triamine. ACS Appl. Mater. Interfaces 4, pp. 536-544 (2012). [cited by applicant]
Li, X., Dong, G. Q., Liu, Z. W. & Zhang, X. T., Polyimide aerogel fibers with superior flame resistance, strength, hydrophobicity, and flexibility made via a universal sol-gel confined transition strategy. ACS Nano 15, … [cited by applicant]
Chidambareswarapattar, C. et al., Fractal multiscale nanoporous polyurethanes: Flexible to extremely rigid aerogels from multifunctional small molecules. Chem. Mater. 25, pp. 3205-3224 (2013). [cited by applicant]
Zhou, S. et al., One-pot synthesis of robust superhydrophobic, functionalized graphene/polyurethane sponge for effective continuous oil-water separation. Chem. Eng. J. 302, pp. 155-162 (2016). [cited by applicant]
Ni, J. H. et al., Strong fatigue-resistant nanofibrous hydrogels inspired by lobster underbelly. Matter 4, pp. 1919-1934 (2021). [cited by applicant]
Picu, R. C., Mechanics of random fiber networks—a review, Soft Matter 7, pp. 6768-6785 (2011). [cited by applicant]
Gibson, I. J. & Ashby, M. F., The mechanics of three-dimensional cellular materials, Proc. R. Soc. Lond. A 382, pp. 43-59 (1982). [cited by applicant]
Zhu, J. et al., Branched aramid nanofibers. Angew. Chem. Int Ed. 56, pp. 11744-11748 (2017). [cited by applicant]
Xu, L. Z., Zhao, X. L., Xu, C. L. & Kotov, N. A., Water-rich biomimetic composites with abiotic self-organizing nanofiber hetwork, Adv. Mater. 30, 1703343, pp. 1-6 (2018). [cited by applicant]
Gibson, L. J., Cellular solids, MRS Bull. 28, pp. 270-274 (2003). [cited by applicant]
Sun, J. Y. et al., Highly stretchable and tough hydrogels, Nature 489, pp. 133-136 (2012). [cited by applicant]
Broedersz, C. P., Mao, X. M., Lubensky, T. C. & Mackintosh, F. C., Criticality and isostaticity in fibre networks, Nat. Phys. 7, pp. 983-988 (2011). [cited by applicant]
Wei, X., Zhu, Q., Qian, J., Lin, Y. & Shenoy, V. B., Response of biopolymer networks governed by the physical properties of cross-linking molecules, Soft Matter 12, pp. 2537-2541 (2016). [cited by applicant]
Chaudhuri, O., Cooper-White, J., Janmey, P. A., Mooney, D. J. & Shenoy, V. B., Effects of extracellular matrix viscoelasticity on cellular behaviour, Nature 584, pp. 535-546 (2020). [cited by applicant]
Sharma, A. et al., Strain-controlled criticality governs the nonlinear mechanics of fibre networks., Nat. Phys. 12, pp. 584-587 (2016). [cited by applicant]
Hisu, P. C. et al., Radiative human body cooling by nanoporous polyethylene textile, Science 353, pp. 1019-1023 (2016). [cited by applicant]
Sun, T. L. et al., Physical hydrogels composed of polyampholytes demonstrate high toughness and viscoelasticity, Nat. Mater. 12, pp. 932-937 (2013). [cited by applicant]
Crisfield, M., A. Non-linear finite element analysis of solids and structures Ch17, (John Wiley & Sons, New York, 1997). [cited by applicant]
Z. Huang, Y. Hao, et al., Three-dimensional integrated stretchable electronics , Nature Electronics, 2018, 1, pp. 473-480. [cited by applicant]
Y. Dai, et al., Stretchable transistors and functional circuits for human-integrated electronics, Nature Electronics. 2021, 1, pp. 17-29. [cited by applicant]
N. Matsuhisa, X. Chen, Z. Bao, T. Someya, Materials and structural designs of stretchable conductors, Chem. Soc. Rev. 2019, 48, pp. 2946-2966. [cited by applicant]
D. C. Kim, H. J. Shim, W. Lee, J. H. Koo, D. H. Kim, Material-Based Approaches for the Fabrication of Stretchable Electronics, Adv. Mater., 2020, 32, 1902743, pp. 1-29. [cited by applicant]
Y. Wang, et al., A highly stretchable, transparent, and conductive polymer, Sci. Adv,. 2017, 3, e1602076, pp. 1-10. [cited by applicant]
S. Choi, et al., Highly conductive, stretchable and biocompatible Ag—Au core-sheath nanowire composite for wearable and implantable bioelectronics Nat. Nanotechnol. 2018, 13, pp. 1048-1056. [cited by applicant]
C. Wang, et al., Materials and Structures toward Soft Electronics, Adv. Mater. 2018, 30, 1801368, pp. 1-49. [cited by applicant]
J. A. Fan, et al, Fractal design concepts for stretchable electronics, Nat. Commun. 2014, 5-3266, pp. 1-8. [cited by applicant]
Y. Wang, et al., Electrically compensated, tattoo-like electrodes for epidermal electrophysiology at scale, Sci. Adv. 2020, 6, eabd0996, pp. 1-13. [cited by applicant]
L. Xu, et al., 3D multifunctional integumentary membranes for spatiotemporal cardiac measurements and stimulation across the entire epicardium, Nat. Commun. 2014, 5, 3329, pp. 1-18. [cited by applicant]
S. Han, et al., Mechanically Reinforced Skin-Electronics with Networked Nanocomposite Elastomer, Adv. Mater. 2016, 28, pp. 10257-10265. [cited by applicant]
Y. Xu, et al., Multiscale porous elastomer substrates for multifunctional on-skin electronics with passive-cooling capabilities, Proc. Natl. Acad. Sci. U. S. A. 2020, 117, pp. 205-213. [cited by applicant]
L. Tian, et al, Large-area MRI-compatible epidermal electronic interfaces for prosthetic control and cognitive monitoring, Nat. Biomed. Eng. 2019, 3, pp. 194-205. [cited by applicant]
Z. Li, et al., All-Fiber Structured Electronic Skin with High Elasticity and Breathability, Adv. Funct. Mater. 2019, 30, 1908411, pp. 1-9. [cited by applicant]
Y. Zhang, et al., A New Class of Electronic Devices Based on Flexible Porous Substrates, Adv. Sci. 2022, 2105084, pp. 1-39. [cited by applicant]
D.-H. Kim, et al., Dissolvable Films of Silk Fibroin for Ultrathin, Conformal Bio-Integrated Electronics, Nat. Mater. 2010, 9, pp. 511-517. [cited by applicant]
S. Liu, et al., Strategies for body-conformable electronics, Matter 2022, 5, pp. 1104-1136. [cited by applicant]
M. K. Blees, et al., Graphene kirigami, Nature 2015, 524, pp. 204-212. [cited by applicant]
T. C. Shyu, et al., A kirigami approach to engineering elasticity in nanocomposites through patterned defects, Nat. Mater. 2015, 14, pp. 785-790. [cited by applicant]
Y. Morikawa, et al., Ultrastretchable Kirigami Bioprobes, Adv. Healthc. Mater. 2018, 7, 1701100, pp. 1-10. [cited by applicant]
A. Lamoureux, et al., Dynamic kirigami structures for integrated solar tracking, Nat. Commun. 2015, 6, 7373., pp. 1-6. [cited by applicant]
K. Yong, et al., Kirigami-inspired strain-insensitive sensors based on atomically-thin materials, Mater. Today 2019, pp. 1-8. [cited by applicant]
L. Xu, et al, Origami and Kirigami Nanocomposites, ACS Nano 2017, 11, pp. 7587-7599. [cited by applicant]
H. Li, et al., 3D Interfacing between Soft Electronic Tools and Complex Biological Tissues, Adv. Mater. 2020, 33, 2004425, pp. 1-17. [cited by applicant]
R. Zhao, et al., Kirigami enhances film adhesion, Soft Matter 2018, 14, pp. 2515-2525. [cited by applicant]
A. Das, et al., Fracture in Microscale SU-8 Polymer Thin Films, Exp. Mech. 2017, 57, pp. 687-701. [cited by applicant]
R. Ballarini, et al., The fracture toughness of polysilicon microdevices: A first report, J. Mater. Res. 1997, 12, pp. 915-922. [cited by applicant]
M. Pharr, et al., Measurements of the Fracture Energy of Lithiated Silicon Electrodes of Li-Ion Batteries, Nano Lett. 2013, 13, pp. 5570-5577. [cited by applicant]
J. Lyu, et al., High Strength Conductive Composites with Plasmonic Nanoparticles Aligned on Aramid Nanofibers, Adv. Funct. Mater. 2016, 26, pp. 8435-8445. [cited by applicant]
H. Li, et al., Breathable and Skin-Conformal Electronics with Hybrid Integration of Microfabricated Multifunctional Sensors and Kirigami-Structured Nanofibrous Substrates, Adv. Funct. Mater. 2022, 2202792, pp. 1-8. [cited by applicant]
Crisfield, M. A., Non-linear finite element analysis of solids and structures. Ch7, John Wiley & Sons, New York, 1997, 509 pages. [cited by applicant]