Calcium Coordinated Poly(acrylic acid) Ion Gels for Strain Sensing
Jie Gao, Zhe Ji, Zhanying Chen, Lina Ding, Song Guo, Yuyang He, Mo Cao, Qingcheng Wu, Jiayin Chen, Wantao Wang, Shiqi Liu, Gai Zhao, Yan Zhang, Jun Zhang, Shiguo ZhangAbstract
Although ion gels show great promise for various applications, their large-scale practical implementation remains hindered by challenges such as poor mechanical properties, lack of self-healing and recyclability, and insufficient interfacial adhesion. Herein, supramolecular ion gels were fabricated via a one-pot UV-initiated polymerization of acrylic acid in the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate (EMImES) using calcium acetate as a dynamic coordination cross-linker. Calcium acetate introduces Ca2+ to form a physically cross-linked network through metal coordination with poly(acrylic acid) chains. The resulting ion gels are characterized by superior stretchability (964%), efficient self-healing (93%), recyclability (83%), high transparency (90%), and robust interfacial adhesion. Ion gel-based strain sensors can detect a range of deformations and human activities, providing sensitive (0–100%, gauge factor (GF) = 1.31), reproducible sensing signals (500 cycles). This work offers a strategy for synthesizing high-performance, recyclable ion gels for sustainable flexible electronics.