Untreated Natural Wood-Based Triboelectric Nanogenerator for Floor Charge Energy Harvesting

Abstract

Triboelectric nanogenerators (TENGs) represent an emerging technology that converts mechanical energy into electrical energy. Nonetheless, the most efficient TENGs are based on synthetic plastics or chemically treated materials. This study demonstrates a chemical-free, natural wood-based TENG with performance comparable to chemically treated wood-TENGs. The natural wood is paired with different polymers as an opposite layers in contact-separation mode, using various electrodes. The pristine wood-polytetrafluoroethylene (PW: PTFE) TENG device with a large area of 3 × 3 cm² exhibits a high open circuit voltage of 110 V, a short-circuit current of 0.72 µA, and generates charge of 23.6 ± 0.3 nC. Finally, to illustrate the viability of PW: PTFE triboelectric devices for practical applications, a prototype with a 20 × 18 cm² active area is discreetly inserted beneath a carpet to harness the energy generated by individuals walking or running across its surface. The cyclic nature of human motion ensures a sustained regimen of contact and separation, thereby yielding a consistent output of voltage and current, with a maximum open circuit voltage of 110 V, a short-circuit current of 193 µA, and a charge of 3.5 µC. These findings suggest that pristine wood is a promising material for low-cost and environmentally friendly TENGs.