Noncovalent cross-linked engineering hydrogel with low hysteresis and high sensitivity for flexible self-powered electronics

In this study, the hydrogel network was reinforced by covalent-like hydrogen bonding, and the strong binding ability of boron–nitrogen coordination served as the main driving force. Among them, acrylamide (AM) and 3-acrylamidophenylboronic acid (AAPBA) were the main body, and the numerous hydroxyl groups in the trehalose (Treh) molecule and other polymer groups formed strong hydrogen bonding interactions to improve the mechanical properties of the PAM/PAAPBA/Treh (PAAT) hydrogel and ensured the simplicity of the synthesis process. The hydrogel possessed high strain at break (1239%), stress (64.7 kPa), low hysteresis (100% to 500% strain, corresponding to dissipation energy from 1.37 to 7.80 kJ/m3), and outstanding cycling stability (retained more than 90% of maximum stress after 200 tensile cycles). By integrating carbon nanotubes (CNTs) into PAAT hydrogel (PAATC), the PAATC hydrogel with excellent strain response performance was successfully constructed. The PAATC conductive hydrogel exhibited high sensitivity (gauge factor (GF)=10.58 and sensitivity (S)=0.304 kPa−1), wide strain response range (0.5%–1000%), fast response time (450 ms), and short recovery time (350 ms), excellent fatigue resistance, and strain response stability. Furthermore, the PAATC-based triboelectric nanogenerator (TENG) displayed outstanding energy harvesting performance, which shows its potential for application in self-powered electronic devices.