The team from the Beijing Institute of Nanoenergy and Nanosystems developed the 'bionic stretchable nanogenerator' (BSNG) that mimicks the ion channels structure of an electric eel’s electrocyte cytomembrane.
Built out of polydimethylsiloxane (PDMS) and silicone, the layered construction consists of an electrification layer and an induction layer. The electrification layer contains a series of controllable channels which connect to a fluid chamber filled with deionized water. Those channels open or close upon stretching or release of the whole elastic construction. Underneath is the induction layer containing two ionic solution (NaCl) electrodes under the channels and chamber of the first layer.
In the experiments, the whole stretchable nanogenerator measured 10×6cm and was 8mm thick.
Upon stretching, the channels in the electrification layer open and draw-in deionized water, coming in contact with the silicone substrate onto which surface negative ions are selectively absorbed (creating an accumulation of negative triboelectric charges).
The liquid in the BSNG is positively charged and the silicone near to the liquid is negatively charged by triboelectrification through the iterative liquid-silicone contact. In the meantime, the induction layer underneath the channels induces electric charges that accumulate on the bottom of upper layer through electrostatic induction.