Printed and Stretchable Triboelectric Energy Harvester Based on P(VDF-TrFE) Porous Aerogel

Developing energy harvesting devices is crucial to mitigate the dependence on conventional and rigid batteries in wearable electronics, ensuring their autonomous operation. Nanogenerators offer a cost-effective solution for enabling continuous operation of wearable electronics. Herein, this study proposes a novel strategy that combines freeze-casting, freeze-drying, and printing technologies to fabricate a fully printed triboelectric nanogenerator (TENG) based on polyvinylidene fluorid-etrifluoroethylene P(VDF-TrFE) porous aerogel. First, the effects of porosity and poling on the stretchability and energy harvesting capabilities of P(VDF-TrFE) are investigated, conducting a comprehensive analysis of this porous structure's impact on the mechanical, ferroelectric, and triboelectric properties compared to solid P(VDF-TrFE) films. The results demonstrate that structural modification of P(VDF-TrFE) significantly enhances stretchability increasing it from 7.7% (solid) to 66.4% (porous). This modification enhances output voltage by 66% and generated charges by 48% for non-poled P(VDF-TrFE) porous aerogel films compared to their non-poled solid counterparts. Then, a fully printed TENG is demonstrated using stretchable materials, exhibiting a peak power of 62.8 mW m⁻² and an average power of 9.9 mW m⁻² over 100 tapping cycles at 0.75 Hz. It can illuminate light-emitting diodes (LEDs) through the harvesting of mechanical energy from human motion. This study provides a significant advance in the development of energy harvesting devices.