Fig. 2. Electrical output performance of triboelectric fibers.

a Finite element simulation of the potential distribution of a fiber with a single liquid metal electrode under open-circuit condition. b Variation of I_sc with frequency of stimulation (contact length: 3 cm). c Dependence of the output voltage and peak instantaneous power on the loaded resistors. d Long-term output stability tests under continuous pressing for 50,000 cycles, together with the outputs after being stored in ambient atmosphere for 2 weeks (contact length: 3 cm). e Variation of I_sc after repeated stretching cycles at 50 and 100% strain for 2,000 cycles, respectively. A longer fiber with the contact length of 10 cm and a slightly larger pressure were used.