Low-cost micro-graphite doped polydimethylsiloxane composite film for enhancement of mechanical-to-electrical energy conversion with aluminum and its application

Background: Poly-(dimethylsiloxane) (PDMS) is widely used as a negative triboelectric material for triboelectric nanogenerator (TENG) to harvest mechanical-converted-to- electricity energy. The process of conventional nanomaterial doped PDMS is complicated for a long time of 5∼72 h. Methods: Here, a facile economic method using the low-cost graphite micro-powders (GP MP) of 2-13 µm rather than high-cost nano-graphene is proposed to modify the PDMS composite (PDMS@GP). The modification can enhance Al-PDMS TENG performance and only take about 2∼3 h. The PDMS@GP composite is made of casting PDMS (11 g) with GP (0.05∼1 g) addition from the reusable laser-ablated PMMA planar master mold. Significant findings: The output performance of Al-PDMS@GP TENG (APGP-TENG) initially increases with GP MP from 0 (pure PDMS) to 0.1 g, then decreases from 0.1 to 1g. The open-circuit voltage (V_OC) and short-circuit current (I_SC) of APGP-TENG at 0.1 g with the maximum output performance are nearly 2.67 and 3.25 times enhancement of the pure PDMS-TENG. Also, the performance of APGP-TENG keeps stable output during 13,000 cycles. It can light up to 102 LEDs connected in series and used for the self-powered digital devices and pressure sensor switch for potential environmental internet of things.