A Stretchable, Wirelessly Rechargeable, Body-Integrated Energy Supply System with On-Demand Energy Release

Stretchable body-integrated energy systems are urgently needed due to the rapid development of wearable and implantable electronic devices. Despite some progress, the challenges of simultaneously achieving sustained energy supply and on-demand release have not been well addressed. Herein, we construct a stretchable, biocompatible energy supply system that seamlessly integrates wireless charging and energy storage modules, as well as a light-controlled switching circuit. The mechanical and electrical properties of the integrated system under various deformation conditions are investigated using finite element analysis. Partially oxidized liquid metal (o-LM) is patterned to prepare the energy-receiving coils, current collector, and electrical connections between different components. Utilizing strong hydrogen bond interaction between o-LM and MXene, biaxial stretchy micro-supercapacitors with high performance are obtained, including high capacitance (121 mF cm^-2) and excellent stretching stability. A switching circuit consisting of a photodiode and a triode is designed to achieve current amplification and on-demand power output. Demonstrations of the integrated system that powers wearable electronic devices and implantable pulsed electrical stimulation, and the biocompatibility evaluation of the system also confirmed its ability to provide a stable and continuous energy supply.