Sustainable Nonwoven Triboelectric Nanogenerator Including Pseudo-Thickness Enabled Consistent Power Generation in Ultralow Contact Frequency

Abstract

A poly(ethylene terephthalate) (PET) nonwoven-fabric-based triboelectric nanogenerator (NWF-TENG) with high energy-harvesting efficiency at ultralow contact frequencies is introduced, enabled by the concept of pseudo-thickness. PET-based NWF exhibits consistent mechanical properties regardless of its origin, even including recycled PET sources, providing the sustainable benefits of the NWF-TENG system. Above all, this study is the first demonstration to analyze the impact of thickness changes in compressible dielectric materials within dielectric-to-dielectric contact TENG models. Through RC decay analysis, it is revealed that the peak-to-peak voltage of compressible NWF-PET is 2,653 V, significantly higher than that of conventional noncompressible film-based TENG (F-TENG). After combining with a power management system, the compressible NWF-TENG achieves a continuous direct current output of 24.8 mW m-2, indicating its potential for powering electronic devices. Lastly, the NWF-TENG exhibits outstanding charge preservation capability at ultralow contact frequencies due to its sustained contact state during compression cycles of the dielectric NWF material. In an application test, a stopwatch is continuously powered by a 0.0025 m2 NWF-TENG operating at a contact frequency of 0.2 Hz. In this work, valuable insights are provided into the design and optimization of the energy harvesting systems using compressing materials with the valid pseudo-thickness concept.