Fig. 1.

Schematic diagram. a A schematic illustration of the functional components of multifunctional TENG. A photograph of b stator and c rotator. The working principles of TENG with the freestanding module: d schematic working principle of TENG (I–III) and e the simulated potential distributions for TENG at three different rolling displacements by COMSOL software. Performance of TENG. f Short-circuit current, g open-circuit Voltage, h short-circuit charge quantity of TENG at different rotation rates. i Capacitor charging ability of the TENG under 100 r min⁻¹. j Current and peak power of the TENG measured with different external load resistances under 100 r min⁻¹. k Stability of open-circuit voltage over 16,000 cycles