Self-healable, super-stretchable and shape-adaptive triboelectric nanogenerator based on double cross-linked PDMS for electronic skins

Self-powered triboelectric nanogenerators (TENG) have shown great potential in the field of electronic skin (E-skin). However, TENG is vulnerable to damage by frequent mechanical impacts during operation. In this work, a self-healable (≤ 2 h), super-stretchable (> 760%) and shape-adaptive TENG was designed as an E-skin to harvest energy and monitor human motion. The triboelectric layer is self-healing double-crosslinked polydimethylsiloxane (PDMS) prepared by adjusting the ratio of imine bonds to hydrogen bonds (H-bonds). The electrode layer is self-healable conductive composite prepared via the formation of H-bonds between MXene and lightly cross-linked PDMS. This TENG can be perfectly attached on the uneven human skin surface due to shape adaptability and can maintain original triboelectric performance after repeated damage. Also, our TENG can switch freely between single sensor and sensor arrays due to high self-healing efficiency, suggesting promising applications in E-skin and wearable device.