Triboelectric Energy Harvester performance enhanced by modifying the tribo-layer with cost-effective fabrication

Abstract

In this paper, a cost-effective fabrication technique to develop triboelectric energy harvester with enhanced performance without using any cleanroom process or costly instruments have been demonstrated. Here, two prototypes of portable TEH device with contact-separation mode have been implemented using dielectric-metal tribo-pair consisting of PDMS polymer film and Copper. Device-1 is implemented with PDMS polymer film having microstructures patterned surface roughness created using soft lithography with Teflon mold. In Device-2, bulk film profile is also altered by incorporating micropores by manipulating Elastomer+Curing agent solution while preparing PDMS film, along with the modified surface profile using soft lithography. Micropores have been formed in the film profile by adding 20 wt% water in Dow Corning Elastomer+Curing agent solution. This water added Dow Corning solution would form micropores, also resulting in cracks during the polymerization. The devices have been developed without using any cleanroom or microfabrication process. The in-house fabricated triboelectric energy harvesters have been tested for performance using low-cost PicoScope 3206D MSO to measure voltage and current-to-voltage converter electronic circuitry for low current measurements. Measured output peak voltage for the Device-1 and Device-2 is 113.63 V and 128.14 V; the measured peak current is 14.23 μA and 15.89 μA respectively. The maximum instantaneous electric power density achieved is 1.20 W m−2 and 1.57 W m−2 for Device-1 and Device-2 respectively which shows the performance enhancement by 30.83%. Electrical measurements are carried out under mechanical vibrations provided to the devices by manual tapping. These devices have been demonstrated in a self-powered LED system in which we could glow 130 LEDs with each TEH device successfully.