Mechanical energy harvesting through a novel flexible contact-separation mode triboelectric nanogenerator based on metallized porous PDMS and Parylene-C

This paper reports the fabrication and preliminary characterization of a novel flexible triboelectric nanogenerator (TENG) which could be employed for driving future low-consumption wearable devices. The single-electrode device operates in contact-separation mode and it is based on a combination of a polysiloxane elastomer and a poly(para-xylylene). In particular, a poly(dimethylsiloxane) (PDMS) substrate was made porous and rough with a steam-curing step; then, it was metallized and an optimal substrate-electrodes adhesion was achieved. Finally, the structure was coated with a thin film of Parylene-C serving as friction layer. This material provides excellent conformability and high charge retaining capability. Performance preliminary tests were conducted by measuring the open-circuit voltage and power density under finger tapping ($\sim$2N) at $\sim$5Hz. The device exhibited a peak-to-peak voltage of 1.51÷3.82V and the peak of power density was $2.24mW/m^{2}$ at $\sim$0.4M $\omega$.