Flexible solid-state Zn-Co MOFs@MXene supercapacitors and organic ion hydrogel sensors for self-powered smart sensing applications

Stable and continuous detection of physiological signals without an external power supply is a crucial technology to realize wearable electronics as the next generation of flexible electronic devices. In this work, a self-powered smart system with flexible solid-state Zn-Co MOFs@MXene supercapacitors and polyacrylamide-BaTiO3/NaCl (PAM-BTO/NaCl) organic ionic hydrogel sensors are designed. The supercapacitor demonstrates a high energy density of 51 Wh/kg at a power density of 1.59 kW/kg. In particular, it maintains exceptional mechanical flexibility under different bending environments. The resistance change rate of the organic ionic hydrogel sensor exhibits a linear response within the strain range of 0-400 % and 400-600 %, respectively, and it shows outstanding electromechanical stability with almost unchanged performance under multiple identical tensile strains. Furthermore, the self-powered integrated system can be conveniently used for real-time detection of human motion and small strains. These findings highlight the unlimited application potential of self-powered integrated system in wearable devices.