Progress on triboelectric nanogenerator with stretchability, self-healability and bio-compatibility

Remarkable progress has been made recently in the development of soft materials and devices for humanmachine interface. Emerging soft-electronics with skin-inspired stretchable, healable and bio-degradable properties have diffused the boundaries of electronics and biology. Practical utilisation of these electronics relies on the development of a skin-inspired soft energy harvester to power them. Mechanical energy harvesters including triboelectric and piezoelectric nanogenerators have emerged as promising energy harvesters for soft-electronics. In this review, we highlight the recent progress in stretchable, self-healing, and bio-compatible soft triboelectric nanogenerators. We explicitly discussed the operating mechanism, design strategies, fabrication techniques, and performances of the stretchable and self-healing energy harvesters. Additionally, the progress of bio-compatible energy harvesters for effective interaction with biological systems is discussed. Finally, we present the perspectives, existing challenges and future road-map for the development of skin-inspired soft mechanical energy harvesters.