Biocompatible and stable quasi-solid-state zinc-ion batteries for real-time responsive wireless wearable electronics

Abstract

Wearable systems for continuous monitoring of muscle activity, data storage, and feedback treatment delivery represent innovative approaches to personalized healthcare. Monitoring the physiological responses of the body requires wearable systems with operational stability and satisfying biocompatibility to track real-time human motion parameters. However, progress of wearable electronics has been hampered by cumbersome power supply with inferior electrochemical stability, poisonous components and rigidity of commercial sensors. Herein, a highly integrated all-in-one strategy, i.e., a biocompatible, lightweight and flexible urea (Ur)-modified sodium alginate (SA) composite hydrogel (Ur–SA) designed as both a wearable strain sensor and the electrolyte of flexible zinc-ion batteries (ZIBs) is reported. Benefiting from the modulated Zn²⁺ solvation structure and the in situ generated electrolyte/electrode interphase in Ur–SA, the screen-printed planar ZIBs guarantee the operationally stable energy supply for a wearable sensing system. The flexibility and superior biocompatibility of Ur–SA validated through in vivo implantation endows itself with superior sensing properties. Especially, the modular wearable sensing system driven by screen-printed ZIBs has superior operational durability, ensuring a stable energy supply to the microcontroller unit (MCU) and biocompatible Ur–SA strain sensors, thereby continuously monitoring real-time physiological signals and human movements and then wirelessly transmitting them to mobile phones. These mark the realization of a safe, stable and biocompatible integrated wearable monitoring system. This design principle provides new insights into multivalent semi-solid electrochemistry, healthcare, implantable biomaterials and biomedical devices.