Humidity-resistant triboelectric energy harvester using electrospun PVDF/PU nanofibers for flexibility and air permeability.

We present a triboelectric energy harvester fabricated with a simple electrospinning process of polyvinylidene fluoride/polyurethane polymers on conductive fabric. This electrospinning process provides higher electrical power output and hydrophobicity driven humidity resistance compared to flat polymer energy harvesters. By using conductive fabric as collector and electrode, the device could retain air permeability and flexibility. The triboelectric energy harvester exhibits a high open-circuit voltage of 45.1 V (at a compressive contact force of 20 N and relative humidity (RH) of 20%), humidity resistance (maintains about 40% of the open-circuit voltage at RH of 80%) and air permeability without deteriorating the air permeability of the fabric. Its durability was tested and shows no significant degradation of electrical output throughout 324,000 cycles of operation. This work suggests an approach for human energy harvesting in textile form with electrospun nanofibers as the contact surfaces of a triboelectric energy harvester.