Triboelectric contact surface charge modulation and piezoelectric charge inducement using polarized composite thin film for performance enhancement of triboelectric generators

We report performance enhancement of triboelectric generators (TEGs) by modulating dielectric permittivity and optimizing the effects from polarized dipoles in the composite thin films, composed of barium titanate nanoparticles (BTO NPs) and polydimethylsiloxane (PDMS). Thanks to BTO's high permittivity and ferroelectric property, the composite thin films provide excellent platforms to examine both permittivity modulation and surface dipole effects on performance of TEGs. Our results show that peal< output power density of the TEGs is increased in proportion to cubic BTO NP wt% in the composite layer, increasing permittivity of it. More interestingly, both contact surface charge density modulation and piezoelectric charge inducement were achieved by polarized tetragonal BTO NPs in the composite layer. By optimizing wt% of tetragonal BTO NPs and polarization of the composite layer, the output performance of TEG was greatly improved, generating the output voltage of similar to 380 V and peak power density of 2.5 mW cm(-2) with a 10 M Omega load resistance. The work here provides simple performance enhancement methods and offers an insight into the roles of both permittivity-induced and polarized dipole-induced effects on the electrical output of TEGs. (C) 2016 Elsevier Ltd. All rights reserved.