Fig. 2. Working principle and electrical output performance of energy harvesting unit (EHU).
a Photographs of the movement process of the pellets in EHU. b Schematic diagram of the working principle of EHU. c Open-circuit voltage (Voc) of EHU when working under different volumes of pellets. (n = 3, Data are presented as mean ± SD) d Voc of EHU when working under different tilt angles. (n = 3, Data are presented as mean ± SD) e Voc, short-circuit current (Isc), and short-circuit charge (Qsc) of EHU in vitro. f Tensile test for SICP (Scale bar = 2 cm). Source data are provided as a Source Data file.