Polymerizable rotaxane hydrogels for three-dimensional printing fabrication of wearable sensors

While hydrogels enable a variety of applications in wearable sensors and electronic skins, they are susceptible to fatigue fracture during cyclic deformations owing to their inefficient fatigue resistance. Herein, acrylated β-cyclodextrin with bile acid is self-assembled into a polymerizable pseudorotaxane via precise host-guest recognition, which is photopolymerized with acrylamide to obtain conductive polymerizable rotaxane hydrogels (PR-Gel). The topological networks of PR-Gel enable all desirable properties in this system due to the large conformational freedom of the mobile junctions, including the excellent stretchability along with superior fatigue resistance. PR-Gel based strain sensor can sensitively detect and distinguish large body motions and subtle muscle movements. The three-dimensional printing fabricated sensors of PR-Gel exhibit high resolution and altitude complexity, and real-time human electrocardiogram signals are detected with high repeating stability. PR-Gel can self-heal in air, and has highly repeatable adhesion to human skin, demonstrating its great potential in wearable sensors.

Xueru Xiong, Yunhua Chen, Zhenxing Wang, Huan Liu, Mengqi Le, Caihong Lin, Gang Wu, Lin Wang, Xuetao Shi, Yong-Guang Jia, Yanli Zhao