Printed N’S-MXene@C/Cu Micro-Supercapacitors with Cryo-Tolerant Hydrogel for Wireless Self-Powered Motion Monitoring.

Abstract

Designing integrated material systems that can simultaneously provide reliable energy storage and real-time sensing under harsh environments remains a major challenge for next-generation wearable electronics. Here, we report a robust, cryo-tolerant, and self-powered sensing platform constructed by integrating inkjet-printed N’S-MXene@C/Cu-based micro-supercapacitors (MSCs) with a multifunctional PVA/LiCl–ethylene glycol (EG) hydrogel, which functions both as a solid-state electrolyte and a stretchable strain sensor. The device retains high ionic conductivity and mechanical compliance at temperatures as low as −30 °C, delivering an areal capacitance of 218.5 mF cm⁻² along with excellent cycling stability. Moreover, seamless integration on a printed circuit board (PCB) enables wireless, real-time joint motion monitoring through Bluetooth transmission. Various human motions, such as wrist bending and neck rotation, are tracked with high signal fidelity without the need for external power. This work demonstrates a scalable strategy for developing flexible, multifunctional, and low-temperature-tolerant electronic platforms, advancing applications in wearable healthcare, soft robotics, and human–machine interfaces.