Enhanced Performance of Triboelectric Nanogenerator by Controlled Pore Size in Polydimethylsiloxane Composites with Au Nanoparticles

Abstract

Based on the contact electrification and electrostatic induction, triboelectric nanogenerators (TENGs) can convert the ambient mechanical energy into an electrical one. Having a role as both an energy storage and an output device, the enhancement of the TENG performance can be achieved by increasing their capacitance. Since the capacitance of tribo-materials can be engineered by their thickness and dielectric constant, we attempted to produce porous polydimethylsiloxane (PDMS) composites with Au nanoparticles (NPs) to engineer the capacitance. To this end, PDMS elastomers with various pore sizes were produced using sugar particles with a range of grain sizes. Then, the hydrophobic surface of PDMS elastomer was coated with polydopamine (PDA) to promote the homogeneous deposition of hydrophilic Au NPs on the PDMS surface. By using PDMS/PDA/Au composites, here we show the importance of pore size in adjusting the capacitance of the tribo-material. In particular, decoration of the PDMS surface with Au NPs engineered the dielectric constant of PDMS/PDA/Au composites, while the introduction of pores reduced the thickness of the composites under external pressure. Consequently, PDMS/PDA/Au composites exhibited enhanced TENG performance in a pore-size dependent manner.