Triboelectric nanogenerator built inside shoe insole for harvesting walking energy

By using the optimized device, a TENG-based shoe insole is used to harvest human walking energy, where the maximum output voltage and current density reached up to 220 V and 40 µA, respectively. We also demonstrate that the fabricated shoe insole using a single layer of TENG can be directly used to light up 30 white light-emitting diodes (LEDs) in serial connection. By taking the merits of this simple fabrication, outstanding performance, robust characteristic and low-cost technology, we believe that TENG can open up great opportunities not only for powering small electronics, but also can contribute to large-scale energy harvesting through engineering design.