Self-powered composites by bioinspired device-to-material integration

The booming Internet of Things will generate diverse requirements for specialized power sources featuring customizable mechanical properties and shapes. However, these features are usually challenging to achieve with traditional batteries. Here, we report the design of self-powered composites (SPCs) by a bioinspired device-to-material integration (DTMI) strategy to break the above shackles. Specifically, commercially cheap small coin cells are employed as functional cell fillers for polymer composites, which are united by bioinspired conductive connections. Meanwhile, the polymer host is 3D printed with a bioinspired configuration to increase the energy density and achieve customizable shapes. The results show that commercial small coin cells (CR927) can work as reinforcement and functional fillers for polymer composites with a high electrochemical compression strength of 158 MPa, as revealed by <i>in situ</i> electrochemical mechanical testing. <i>Via</i> the DTMI strategy, SPCs have been successfully fabricated with either high mechanical strength or stretchability. Enabled by these features, SPCs are further demonstrated to be promising building blocks for self-powered electrical vehicles and wearable electronics. Moreover, a stretchable SPC with slidable cell-connection is demonstrated as a smart sensor for stretching rate due to an electrochemistry-polymer relaxation coupling process. This study may open an avenue for self-powered materials for electrical vehicles, robotics, wearable electronics, and beyond.