High-performance triboelectric nanogenerator based on chitin for mechanical-energy harvesting and self-powered sensing.

Environment issues and energy crisis call for eco-friendly, biodegradable and low-cost natural materials for the extensive application of distributed energy harvesting triboelectric nanogenerators (TENGs) and multi-functional self-powered sensors. Here, flexible, robust and transparent chitin films fabricated via non-freezing dissolution approach in KOH/urea were used as tribopositive material to assemble TENGs, which served as outstanding mechanical energy harvesters and multi-functional self-powered sensors. The tensile strength and elongation at break of the chitin film reached 84.7 MPa and 14.5%, better than most existing biodegradable-based films. The chitin-based TENG (CF-TENG) achieved open-circuit voltage up to 182.4 V, short-circuit current of 4.8 μA and maximum power density over 1.25 W m. Furthermore, the CF-TENG can be utilized as tactile sensors for handwriting recognition and health monitoring of subtle pressures, as well as non-contact sensation, exhibiting great potential as self-powered sensors and human-machine interfaces.