Self-Assembled Ultrathin Polymeric Multilayers for Triboelectric Energy Harvesting Coatings

Abstract

Thin films of poly(allylamine hydrochloric acid) (PAH)and poly(phyticacid) (PA) were assembled on graphene-based substrates via layer-by-layer(LbL) assembly. This LbL assembly produced novel, cheap, facile, andreplicable thin films with controlled surface chemical compositions.The surface charge density of the frictional layers was enhanced owingto the presence of nitrogen and oxygen functional groups. The filmwas used as the positive triboelectric material, significantly improvingthe performance of a triboelectric nanogenerator (TENG). A 0.46 & mu;mthick 10-bilayer PAH/PA nanocoating film TENG exhibited an outputpeak voltage, current density, and power density of approximately288 V, 74.5 mA m(-2), and 21.5 W m(-2) at 5.5 Hz and 5 N, respectively, owing to its higher surface potentialof 475 mV, and powered a portable calculator in seconds. This 10-bilayerPAH/PA film was successfully grown on cotton fabric, assembled ona laboratory coat to demonstrate scalability and shape adaptability,obtained 500 V, and lit 38 green light-emitting diodes by tappingthe single-electrode mode TENG. Thus, this eco-friendly self-assemblednanocoating of biocompatible tribomaterials can be advantageous forconstructing new TENG devices for self-powered wearable electronics.