Base-treated polydimethylsiloxane surfaces as enhanced triboelectric nanogenerators

Due to its flexibility, transparency, easy fabrication, and high negative polarity, polydimethylsiloxane (PDMS) has been considered as one of the most appropriate materials for the use in triboelectric nanogenerator (TENG) applications. Here, we report the significantly enhanced triboelectric surface charge of PDMS simply by sprinkling of NaOH solution. Fresh PDMS-based TENGs generated an open-circuit voltage of 18 V and a closed-circuit current of 65 nA after the contact/separation from an indium tin oxide (ITO) electrode. After sprinkling the PDMS surface with 1 M NaOH, in contrast, the resulting TENG generated voltage of 10.4 V and current of 179 nA. Exposing the PDMS to ultraviolet-ozone prior to sprinkling with NaOH solution resulted in a triboelectric voltage and current of 49.3 V and 1.16 mu A, respectively, which are almost 15fold larger than those of fresh PDMS. The origin of the enhanced triboelectric charge is related with an increase of polar Si-0 bonds at the expense of non-polar Si-CH3 bonds in PDMS. This work demonstrates a cost-effective method for producing large-area and high-efficiency PDMSbased TENGs and helps clarify the triboelectric mechanism of PDMS. (C) 2015 Elsevier Ltd. All rights reserved.