Compliant Iontronic Triboelectric Gels with Phase-Locked Structure Enabled by Competitive Hydrogen Bonding

doi:10.1007/s40820-024-01387-4

Abstract
Figure/Table
References
Related Citation (5)

Download: PDF (5398 KB) HTML (0 KB)
Export: BibTeX | EndNote (RIS)

Abstract

Rapid advancements in flexible electronics technology propel soft tactile sensing devices toward high-level biointegration, even attaining tactile perception capabilities surpassing human skin. However, the inherent mechanical mismatch resulting from deficient biomimetic mechanical properties of sensing materials poses a challenge to the application of wearable tactile sensing devices in human-machine interaction. Inspired by the innate biphasic structure of human subcutaneous tissue, this study discloses a skin-compliant wearable iontronic triboelectric gel via phase separation induced by competitive hydrogen bonding. Solvent-nonsolvent interactions are used to construct competitive hydrogen bonding systems to trigger phase separation, and the resulting soft-hard alternating phase-locked structure confers the iontronic triboelectric gel with Young's modulus (6.8-281.9 kPa) and high tensile properties (880%) compatible with human skin. The abundance of reactive hydroxyl groups gives the gel excellent tribopositive and self-adhesive properties (peel strength > 70 N m⁻¹). The self-powered tactile sensing skin based on this gel maintains favorable interface and mechanical stability with the working object, which greatly ensures the high fidelity and reliability of soft tactile sensing signals. This strategy, enabling skin-compliant design and broad dynamic tunability of the mechanical properties of sensing materials, presents a universal platform for broad applications from soft robots to wearable electronics.

Key words： Triboelectric nanogenerator Cellulose Triboelectric gel Self-powered sensor Energy harvesting

Received: 20 January 2024 Published: 09 April 2024

Corresponding Authors: Shuangxi Nie

	Service

	E-mail this article
	Add to my bookshelf
	Add to citation manager
	E-mail Alert
	RSS
	Articles by authors
	Guoli Du
	Yuzheng Shao
	Bin Luo
	Tao Liu
	Jiamin Zhao
	Ying Qin
	Jinlong Wang
	Song Zhang
	Mingchao Chi
	Cong Gao
	Yanhua Liu
	Chenchen Cai
	Shuangfei Wang
	Shuangxi Nie

Cite this article:

Guoli Du,Yuzheng Shao,Bin Luo, et al. Compliant Iontronic Triboelectric Gels with Phase-Locked Structure Enabled by Competitive Hydrogen Bonding[J]. Nano-Micro Letters, 2024, 16(1): 170-.

URL:

https://www.qk.sjtu.edu.cn/nml/EN/10.1007/s40820-024-01387-4 OR https://www.qk.sjtu.edu.cn/nml/EN/Y2024/V16/I1/170

Fig. 1 Design principle of bioinspired compliant triboelectric gels. a Natural phase-locked structures in human subcutaneous tissue. b Process of inducing phase separation via solvent-unsolvent effects to construct phase-locked structures. c Compliant contact of RCPTG with human skin without any adhesive. d Properties of RCPTG compared to reported elastic triboelectric materials, including flexibility, stretchability, toughness, triboelectric responsivity, adhesion, and transparency. e RCPTG-based on-skin device is loaded on the small arm of the human body

Fig. 2 Phase separation induced by hydrogen bonding competition strategy. a Schematic diagram of a rigid-flexible network with phase separation features. b Process of inducing phase separation through solvent-nonsolvent effects. c Snapshots of MD in cellulose regeneration processes. d XRD spectra of gels with different HEMA contents. e 2D WAXS patterns of gels with different cellulose contents. f CLSM images show areas of increasing degree of phase separation, with the bright portion being the RC after staining, scale: 200 μm

Fig. 3 Effect of phase separation on rheological and environmental stability of triboelectric gels. a Preparation process of RCPTG with phase-locked structure. b Computed tomography reconstruction of phase-locked structures in RCPTG by nano-CT. c AFM phase diagram of RCPTGs. d The linear viscoelastic region of RCPTGs. e Frequency loss factors for RCPTGs. f TGA analysis of RCPTGs. g Moisture absorption and environmental stability of RCPTGs

Fig. 4 Skin-like compliant mechanical properties enabled by phase separation strategy. a Interphase load transfer mechanism in phase-locked structure of RCPTG. b Tensile stress-strain curve. c Stretching cycle curves, insets show the original state and the RCPTG stretched to 400%, respectively. d Young’s modulus of RCPTGs, where the Young’s modulus of RCPTG-2.0 is within the modulus interval of human skin tissue. Inset: RCPTGs suspended with 100 g weights. e Comparison of toughness of RCPTGs. Inset: puncture resistance of RCPTG. f Comparison of modulus and strength of RCPTG with reported elastic materials. g Comparison of RCPTG with commercial gels (Ecoflex, PDMS). h Peel strength of RCPTG with glass, PMMA, and pigskin, respectively. i RCPTG forms a favorable conformal contact with human epidermal wrinkles. j RCPTG-skin with flexible circuitry and its detailed view

Fig. 5 Self-powered perception properties of triboelectric tactile skin. a Compliant RCPTG-skin configured on a finger. b Images of RCPTG-skin before (top) and after (bottom) being stretched. c Self-powered sensing mechanism of RCPTG-skin based single-electrode triboelectric nanogenerator. d Contact electrification properties of RCPTG-skin paired with different commercial materials. e Self-powered response and relaxation time of RCPTG-skin. f Image of RCPTG-skin when subjected to destructive crushing by a vehicle weighing 1.58 t. g Comparison of the triboelectric output of RCPTG-skin before and after crush. h Sensing stability of RCPTG-skin at ~ 2000 cycles. i Image of a triboelectric tactile sensory system. j A robotic hand integrated with self-powered tactile skin serves as an operable haptic gripper that recognizes grasping motions and strengths based on the magnitude of triboelectric signals

1.	Y. Jiang, S. Ji, J. Sun, J. Huang, Y. Li et al., A universal interface for plug-and-play assembly of stretchable devices. Nature 614, 456-462 (2023).
2.	Y. Huang, J. Zhou, P. Ke, X. Guo, C.K. Yiu et al., A skin-integrated multimodal haptic interface for immersive tactile feedback. Nat. Electron. 6, 1020-1031 (2023).
3.	X. Meng, C. Cai, B. Luo, T. Liu, Y. Shao et al., Rational design of cellulosic triboelectric materials for self-powered wearable electronics. Nano-Micro Lett. 15, 124 (2023).
4.	T. Jin, Z. Sun, L. Li, Q. Zhang, M. Zhu et al., Triboelectric nanogenerator sensors for soft robotics aiming at digital twin applications. Nat. Commun. 11, 5381 (2020).
5.	Y. Shao, G. Du, B. Luo, T. Liu, J. Zhao et al., A tough monolithic-integrated triboelectric bioplastic enabled by dynamic covalent chemistry. Adv. Mater. (2024).
6.	C. Gao, W. Zhang, T. Liu, B. Luo, C. Cai et al., Hierarchical porous triboelectric aerogels enabled by heterointerface engineering. Nano Energy 121, 109223 (2024).
7.	X. Wang, Y. Zhang, X. Zhang, Z. Huo, X. Li et al., A highly stretchable transparent self-powered triboelectric tactile sensor with metallized nanofibers for wearable electronics. Adv. Mater. 30, e1706738 (2018).
8.	P. Zhang, W. Guo, Z.H. Guo, Y. Ma, L. Gao et al., Dynamically crosslinked dry ion-conducting elastomers for soft iontronics. Adv. Mater. 33, e2101396 (2021).
9.	J. Zhao, W. Zhang, T. Liu, B. Luo, Y. Qin et al., Multiscale structural triboelectric aerogels enabled by self-assembly driven supramolecular winding. Adv. Funct. Mater. (2024).
10.	H.C. Ates, P.Q. Nguyen, L. Gonzalez-Macia, E. Morales-Narváez, F. Güder et al., End-to-end design of wearable sensors. Nat. Rev. Mater. 7, 887-907 (2022).
11.	S. Chen, L. Sun, X. Zhou, Y. Guo, J. Song et al., Mechanically and biologically skin-like elastomers for bio-integrated electronics. Nat. Commun. 11, 1107 (2020).
12.	Z. Yan, D. Xu, Z. Lin, P. Wang, B. Cao et al., Highly stretchable van der Waals thin films for adaptable and breathable electronic membranes. Science 375, 852-859 (2022).
13.	S. Wang, Y. Fang, H. He, L. Zhang, C.-A. Li et al., Wearable stretchable dry and self-adhesive strain sensors with conformal contact to skin for high-quality motion monitoring. Adv. Funct. Mater. 31, 2007495 (2021).
14.	Z. Li, P. Zhang, Y. Shao, Z.-H. Guo, X. Pu, Stretchable iontronics with robust interface bonding between dielectric and ion-conducting elastomers. Nano Res. 16, 11862-11870 (2023).
15.	J. Min, J. Tu, C. Xu, H. Lukas, S. Shin et al., Skin-interfaced wearable sweat sensors for precision medicine. Chem. Rev. 123, 5049-5138 (2023).
16.	D. Choi, Y. Lee, Z.-H. Lin, S. Cho, M. Kim et al., Recent advances in triboelectric nanogenerators: from technological progress to commercial applications. ACS Nano 17, 11087-11219 (2023).
17.	H.L. Wang, Z.H. Guo, X. Pu, Z.L. Wang, Ultralight iontronic triboelectric mechanoreceptor with high specific outputs for epidermal electronics. Nano-Micro Lett. 14, 86 (2022).
18.	Y. Qin, J. Mo, Y. Liu, S. Zhang, J. Wang et al., Stretchable triboelectric self-powered sweat sensor fabricated from self-healing nanocellulose hydrogels. Adv. Funct. Mater. 32, 2201846 (2022).
19.	M. Ilami, H. Bagheri, R. Ahmed, E.O. Skowronek, H. Marvi, Materials, actuators, and sensors for soft bioinspired robots. Adv. Mater. 33, e2003139 (2021).
20.	L. Li, J. Wang, K. Yang, Z.H. Guo, J. Zhang et al., A recyclable, adhesive and fast self-healable ionic conducting elastomer based on a poly-zwitterionic liquid for soft iontronics. J. Mater. Chem. A 10, 24581-24589 (2022).
21.	L. Zhang, S. Wang, Z. Wang, Z. Liu, X. Xu et al., Temperature-mediated phase separation enables strong yet reversible mechanical and adhesive hydrogels. ACS Nano 17, 13948-13960 (2023).
22.	B. Luo, C. Cai, T. Liu, X. Meng, X. Zhuang et al., Multiscale structural nanocellulosic triboelectric aerogels induced by hofmeister effect. Adv. Funct. Mater. 33, 2306810 (2023).
23.	F. Chen, X. Li, Y. Yu, Q. Li, H. Lin et al., Phase-separation facilitated one-step fabrication of multiscale heterogeneous two-aqueous-phase gel. Nat. Commun. 14, 2793 (2023).
24.	J. Chen, Y. Gao, L. Shi, W. Yu, Z. Sun et al., Phase-locked constructing dynamic supramolecular ionic conductive elastomers with superior toughness, autonomous self-healing and recyclability. Nat. Commun. 13, 4868 (2022).
25.	M. Zhang, R. Yu, X. Tao, Y. He, X. Li et al., Mechanically robust and highly conductive ionogels for soft ionotronics. Adv. Funct. Mater. 33, 2208083 (2023).
26.	B. Bao, Q. Zeng, K. Li, J. Wen, Y. Zhang et al., Rapid fabrication of physically robust hydrogels. Nat. Mater. 22, 1253-1260 (2023).
27.	J. Wang, Y. Zheng, T. Cui, T. Huang, H. Liu et al., Bioinspired ultra-robust ionogels constructed with soft-rigid confinement space for multimodal monitoring electronics. Adv. Funct. Mater. 34, 2312383 (2024).
28.	H. Xiang, X. Li, B. Wu, S. Sun, P. Wu, Highly damping and self-healable ionic elastomer from dynamic phase separation of sticky fluorinated polymers. Adv. Mater. 35, e2209581 (2023).
29.	M. Wang, P. Zhang, M. Shamsi, J.L. Thelen, W. Qian et al., Tough and stretchable ionogels by in situ phase separation. Nat. Mater. 21, 359-365 (2022).
30.	J. Wu, Z. Zhang, Z. Wu, D. Liu, X. Yang et al., Strong and ultra-tough supramolecular hydrogel enabled by strain-induced microphase separation. Adv. Funct. Mater. 33, 2210395 (2023).
31.	H. Wan, B. Wu, L. Hou, P. Wu, Amphibious polymer materials with high strength and superb toughness in various aquatic and atmospheric environments. Adv. Mater. 36, e2307290 (2024).
32.	A.N. Annaidh, K. Bruyère, M. Destrade, M.D. Gilchrist, M. Otténio, Characterization of the anisotropic mechanical properties of excised human skin. J. Mech. Behav. Biomed. Mater. 5, 139-148 (2012).
33.	A. Pissarenko, M.A. Meyers, The materials science of skin: analysis, characterization, and modeling. Prog. Mater. Sci. 110, 100634 (2020).
34.	D. Zhao, B. Pang, Y. Zhu, W. Cheng, K. Cao et al., A stiffness-switchable, biomimetic smart material enabled by supramolecular reconfiguration. Adv. Mater. 34, e2107857 (2022).
35.	X. Liang, S.A. Boppart, Biomechanical properties of in vivo human skin from dynamic optical coherence elastography. IEEE Trans. Biomed. Eng. 57, 953-959 (2010).
36.	G. Balakrishnan, J. Song, C. Mou, C.J. Bettinger, Recent progress in materials chemistry to advance flexible bioelectronics in medicine. Adv. Mater. 34, e2106787 (2022).
37.	X. Li, S. Xiang, D. Ling, S. Zhang, C. Li et al., Stretchable, self-healing, transparent macromolecular elastomeric gel and PAM/carrageenan hydrogel for self-powered touch sensors. Mater. Sci. Eng. B 283, 115832 (2022).
38.	S. Li, G. Liu, H. Wen, G. Liu, H. Wang et al., A skin-like pressure- and vibration-sensitive tactile sensor based on polyacrylamide/silk fibroin elastomer. Adv. Funct. Mater. 32, 2111747 (2022).
39.	J. Jiang, Q. Guan, Y. Liu, X. Sun, Z. Wen, Abrasion and fracture self-healable triboelectric nanogenerator with ultrahigh stretchability and long-term durability. Adv. Funct. Mater. 31, 2105380 (2021).
40.	Y. Guo, S. Chen, L. Sun, L. Yang, L. Zhang et al., Degradable and fully recyclable dynamic thermoset elastomer for 3D-printed wearable electronics. Adv. Funct. Mater. 31, 2009799 (2021).
41.	Y. Hishikawa, E. Togawa, T. Kondo, Characterization of individual hydrogen bonds in crystalline regenerated cellulose using resolved polarized FTIR spectra. ACS Omega 2, 1469-1476 (2017).
42.	S. Zhu, Y. Wu, Q. Chen, Z. Yu, C. Wang et al., Dissolution of cellulose with ionic liquids and its application: a mini-review. Green Chem. 8, 325-327 (2006).
43.	R. Guo, Q. Zhang, Y. Wu, H. Chen, Y. Liu et al., Extremely strong and tough biodegradable poly(urethane) elastomers with unprecedented crack tolerance via hierarchical hydrogen-bonding interactions. Adv. Mater. 35, e2212130 (2023).
44.	L. Chen, C. Zhao, J. Huang, J. Zhou, M. Liu, Enormous-stiffness-changing polymer networks by glass transition mediated microphase separation. Nat. Commun. 13, 6821 (2022).
45.	Y. Lai, X. Kuang, P. Zhu, M. Huang, X. Dong et al., Colorless, transparent, robust, and fast scratch-self-healing elastomers via a phase-locked dynamic bonds design. Adv. Mater. 30, e1802556 (2018).
46.	A.-L. Esquirol, P. Sarazin, N. Virgilio, Tunable porous hydrogels from cocontinuous polymer blends. Macromolecules 47, 3068-3075 (2014).
47.	G. Ge, K. Mandal, R. Haghniaz, M. Li, X. Xiao et al., Deep eutectic solvents-based ionogels with ultrafast gelation and high adhesion in harsh environments. Adv. Funct. Mater. 33, 2207388 (2023).
48.	D. Zhao, Y. Zhu, W. Cheng, G. Xu, Q. Wang et al., A dynamic gel with reversible and tunable topological networks and performances. Matter 2, 390-403 (2020).
49.	C. Zhang, Z. Wang, H. Zhu, Q. Zhang, S. Zhu, Dielectric gels with microphase separation for wide-range and self-damping pressure sensing. Adv. Mater. 36, e2308520 (2024).
50.	E. Ducrot, Y. Chen, M. Bulters, R.P. Sijbesma, C. Creton, Toughening elastomers with sacrificial bonds and watching them break. Science 344, 186-189 (2014).
51.	K. Sato, T. Nakajima, T. Hisamatsu, T. Nonoyama, T. Kurokawa et al., Phase-separation-induced anomalous stiffening, toughening, and self-healing of polyacrylamide gels. Adv. Mater. 27, 6990-6998 (2015).
52.	Y. Wang, Y. Liu, N. Hu, P. Shi, C. Zhang et al., Highly stretchable and self-healable ionogels with multiple sensitivity towards compression, strain and moisture for skin-inspired ionic sensors. Sci. China Mater. 65, 2252-2261 (2022).
53.	V.R. Feig, H. Tran, M. Lee, Z. Bao, Mechanically tunable conductive interpenetrating network hydrogels that mimic the elastic moduli of biological tissue. Nat. Commun. 9, 2740 (2018).
54.	K.-X. Hou, S.-P. Zhao, D.-P. Wang, P.-C. Zhao, C.-H. Li et al., A puncture-resistant and self-healing conductive gel for multifunctional electronic skin. Adv. Funct. Mater. 31, 2107006 (2021).
55.	L. Cai, J. Fan, S. Ding, D. He, X. Zeng et al., Soft composite gels with high toughness and low thermal resistance through lengthening polymer strands and controlling filler. Adv. Funct. Mater. 33, 2207143 (2023).
56.	M. Zammali, S. Liu, W. Yu, A biomimetic skin-like sensor with multiple sensory capabilities based on hybrid ionogel. Sens. Actuat. A Phys. 330, 112855 (2021).
57.	E.K. Boahen, B. Pan, H. Kweon, J.S. Kim, H. Choi et al., Ultrafast, autonomous self-healable iontronic skin exhibiting piezo-ionic dynamics. Nat. Commun. 13, 7699 (2022).
58.	G. Du, J. Wang, Y. Liu, J. Yuan, T. Liu et al., Fabrication of advanced cellulosic triboelectric materials via dielectric modulation. Adv. Sci. 10, e2206243 (2023).
59.	D. Lu, T. Liu, X. Meng, B. Luo, J. Yuan et al., Wearable triboelectric visual sensors for tactile perception. Adv. Mater. 35, e2209117 (2023).
60.	Z. Huang, X. Chen, S.J.K. O’Neill, G. Wu, D.J. Whitaker et al., Highly compressible glass-like supramolecular polymer networks. Nat. Mater. 21, 103-109 (2022).
61.	X. Qu, Z. Liu, P. Tan, C. Wang, Y. Liu et al., Artificial tactile perception smart finger for material identification based on triboelectric sensing. Sci. Adv. 8, eabq2521 (2022).
62.	J. Wang, Y. Liu, T. Liu, S. Zhang, Z. Wei et al., Dynamic thermostable cellulosic triboelectric materials from multilevel-non-covalent interactions. Small (2023).

Links