Semiconducting poly(3-hexylthiophene) (P3HT)-functionalized rayon for hybrid mechanical-thermal energy harvesting in fabric triboelectric nanogenerators

Abstract

The fabric triboelectric nanogenerator (F-TENG) is emerging as a promising nanogenerator platform for wearable electronics and electronic textiles. In this work, a modified fabric incorporating the semiconductor polymer poly (3-hexylthiophene) (P3HT) is designed to address the limited output performance by harvesting frictiongenerated waste heat in addition to mechanical energy. The P3HT is incorporated into rayon fabric via a simple coating process, enabling the fabric to function as a dual mechanical-thermal energy harvesting material. During the sliding process, temperature evolution at the interface is monitored by a thermal camera and thermal probes to correlate heat generation with output enhancement. The electrical and thermoelectric characteristics of the rayon-P3HT fabrics are evaluated in terms of electrical conductivity, Seebeck coefficient, and power factor. Multiphysics simulations performed using COMSOL are further employed to support the experimental trends. Owing to the combined triboelectric and thermoelectric contributions, the fabric-based device achieves an improved open-circuit voltage (VOC), short-circuit current (ISC), and maximum output power (Pmax) of ~62 V, ~44 μA and ~ 1204 μW (~133.8 μW/cm2 ), respectively, sufficient to power a digital watch and 360 LEDs. The role of fabric modification by P3HT in enabling triboelectric-thermoelectric coupling and the associated charge generation mechanism is discussed.