Fabrication of triboelectric nanogenerators based on electrospun polyimide nanofibers membrane

Abstract

Surface modifcation of polyimides (PIs) using electrospinning would signifcantly improve the performance of TENGs because of the larger surface area of the electrospun friction layer. However, PIs generally have high solvent resistance, so it is complicated to convert them into nanofbers using electrospinning process. This study aims to fabricate PI nanofbers via simple, one-step electrospinning and utilize them as a friction layer of TENGs for better performance. PI nanofbers were directly electrospun from PI ink made of polyimide powder without any additional process. The efect of PI concentration on spinnability was investigated. Uniform and continuous nanofbrous structures were successfully produced at concentrations of 15wt% and 20wt%. Electrospun PI nanofbers were then utilized as a friction layer for TENGs. A TENG with 20wt% produced an open circuit voltage of 753V and a short circuit current of 10.79 μA and showed a power density of 2.61Wm−2 at a 100 MΩ load resistance. During tapping experiment of 10,000 cycles, the TENG could stably harvest electrical energy. The harvested energy from the proposed TENG is sufcient to illuminate more than 55 LEDs and drive small electronic devices, and the TENGs exhibit excellent performance as a wearable energy harvester.