Unique Contact Point Modification Technique for Boosting the Performance of a Triboelectric Nanogenerator and Its Application in Road Safety Sensing and Detection.

A triboelectric nanogenerator (TENG) is a potential technique that can convert waste kinetic energy to electrical energy by contact separation followed by electrostatic induction. Herein, a unique contact point modification technique has been reviewed carefully via the enlargement of the effective surface area of the tribo layer by using a simple and scalable printing method. In this study, the zinc sulfide (ZnS) nanostructure morphology has been introduced directly on an aluminum electrode (Al) as a tribo positive layer by a modified hydrothermal method and different line patterns directly printed on overhead projector (OHP) transparent sheets by a monochrome laser printer as a tribo negative layer to increase the effective contact area and work-function difference between two tribo layers. This dual parameter results in ∼11 times increment in the open-circuit output voltage (∼420 V) and ∼17 times increment in the short-circuit current density (∼83.33 mA m) compared to the normal one. Furthermore, with the proposed surface modification technique, an ultrahigh instantaneous output power density of ∼3.9 W m at a load resistance of 2 MΩ was easily achieved. The direct energy conversion efficiency reached up to 66.67% at 2 MΩ load, which is very high compared to other traditional TENGs. Further, the fabricated TENG demonstrated efficacy in novel road safety sensing applications in hilly areas to control vehicle movement. Therefore, the current idea of surface engineering using a laser printer will be helpful for energy-harvesting enthusiasts to develop more efficient nanogenerators for higher energy conversions.