Self-healing liquid metal hydrogel for human-computer interaction and infrared camouflage

Xiaofei Li; Miao Jiang; Yiming Du; Xin Ding; Chao Xiao; Yanyan Wang; Yanyu Yang; Yizhi Zhuo; Kang Zheng; Xianglan Liu; Lin Chen; Yi Gong; Xingyou Tian; Xian Zhang

doi:10.1039/d3mh00341h

Self-healing liquid metal hydrogel for human-computer interaction and infrared camouflage

Mater Horiz. 2023 Jul 31;10(8):2945-2957. doi: 10.1039/d3mh00341h.

Authors

Xiaofei Li^{1

2}, Miao Jiang^{1

2}, Yiming Du^{1

2}, Xin Ding¹, Chao Xiao¹, Yanyan Wang¹, Yanyu Yang³, Yizhi Zhuo¹, Kang Zheng¹, Xianglan Liu¹, Lin Chen¹, Yi Gong¹, Xingyou Tian^{1

2}, Xian Zhang^{1

2}

Affiliations

¹ Key Laboratory of Photovoltaic and Energy Conservation Materials, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China. xzhang@issp.ac.cn.
² University of Science and Technology of China, Hefei 230026, China.
³ College of Materials Science and Engineering, Zhengzhou University, Zhengzhou, Henan 450001, China. yyyang@zzu.edu.cn.

PMID: 37165676
DOI: 10.1039/d3mh00341h

Abstract

Due to their mechanical flexibility, conductive hydrogels have been widely investigated in the fields of flexible electronics and soft robots, but their non-negligible disadvantages, such as poor toughness and limited self-healing, severally restrict their practical application. Herein, gallium indium alloy (EGaIn) is utilized to initiate the polymerization and simultaneously serve as flexible fillers to construct a super-stretchable and self-healing liquid metal/polyvinyl alcohol/p(acrylamide-co-octadecyl methacrylate) (liquid metal/PVA/P(AAm-co-SMA)) double network hydrogel (LM hydrogel). The synergistic effect of the rigid PVA microcrystal network and the ductile P(AAm-co-SMA) hydrophobic network, together with the ionic coordination and hydrogen bonds between polymer networks (multiple physical cross-links), endow the LM hydrogel with excellent super-stretchability (2000%), toughness (3.00 MJ m^-3), notch resistance, and self-healing property (healing efficiency > 99% at 25 °C after 24 h). The LM hydrogel exhibits sensitive strain sensing behavior, allowing human-computer interaction to achieve motion recognition and health monitoring. Significantly, owing to the excellent photothermal effect and low infrared emissivity of EGaIn, the LM hydrogel reveals great potential in infrared camouflage. The work of self-healing conductive liquid metal hydrogels will promote the research and practical application of hydrogels and liquid metal in intelligent devices and military fields.