Anti-Freezing and Ultrasensitive Zwitterionic Betaine Hydrogel-Based Strain Sensor for Motion Monitoring and Human–Machine Interaction

Abstract

Ultrasensitive and reliable conductive hydrogels are significant in the construction of human−machine twinning systems. However, in extremely cold environments, freezing severely limits the application of hydrogel-based sensors. Herein, building on biomimetics, a zwitterionic hydrogel was elaborated for human−machine interaction employing multichemical bonding synergies and experimental signal analyses. The covalent bonds, hydrogen bonds, and electrostatic interactions construct a dense double network structure favorable for stress dispersion and hydrogen bond regeneration. In particular, zwitterions and ionic conductors maintained excellent strain response (99 ms) and electrical sensitivity (gauge factor = 14.52) in the dense hydrogel structure while immobilizing water molecules to enhance the weather resistance (−68 °C). Inspired by the high sensitivity, zwitterionic hydrogel-based strain sensors and remote-control gloves were designed by analyzing the experimental signals, demonstrating promising potential applications within specialized flexible materials and human−machine symbiotic systems.

All-Textile Piezoelectric Nanogenerator Based on 3D Knitted Fabric Electrode for Wearable Applications

“…They can convert external mechanical actions into recognizable signals in real-time. Recently, they have attracted much attention. − Wearable flexible sensors with different sensing mechanisms have been developed, mainly including piezoresistive, capacitive, triboelectric, and piezoelectric flexible sensors. Piezoresistive sensors respond to external stimuli by changing resistance, and the performance of many piezoresistive sensors depends on the mechanical stability of the conductive network.…”