Enhanced Triboelectric Nanogenerator Performance via an Optimised Low Permittivity, Low Thickness Substrate

With electrical power generated from mechanical contact, the triboelectric nanogenerators (TEN Gs) have attracted attention recently as a promising route to realising self-powered sensors (e.g. tactile sensors, biomedical sensors etc.). Due to their limited power range (0.1-100 mW/cm²), it is important to optimise the output performance of TENGs. Among the factors that confer higher performance are materials with a strong triboelectric effect and materials with low permittivity. It can be difficult to realize these two benefits in a single contact material. This paper presents a solution to this challenge by optimising a low permittivity substrate beneath the tribo-contact layer. Results are simulated over a range of both substrate permittivity and thickness. The open circuit voltage is found to increase by a factor of 1.8 in moving from PVDF to the lower permittivity PTFE and by a further factor of 37.2 when the substrate thickness is reduced from 200 to $\pmb{1\ \mu}\mathbf{m}$. For PTFE with $\pmb{1\ \mu}\mathbf{m}$ thickness, this amounts to 12.2 kV, as against 327V known from simulations up to now. These results clearly indicate that optimized low permittivity, low thickness substrates represent a potential route to self-powered sensors.