Development of a Broadband Triboelectric Energy Harvester With SU-8 Micropillars

This paper describes a broadband energy harvester working on the principle of contact electrification or triboelectric charging. Design and fabrication of the device have been discussed. The device uses contact and separation mechanism using a cantilever to generate triboelectric charges. This mechanism introduces nonlinearity in the cantilever, which results in broadband behavior of triboelectric energy harvester. The device uses SU-8 micropillar arrays to enhance the triboelectric charging. A study is conducted to study the effect of the micropillar sizes on the power output of devices. The devices were tested at different acceleration levels. The peak power output achieved is 0.91 μW at an acceleration of 1g. The amplitude limiter based design of the energy harvester enables broadening of operating bandwidth as the acceleration level increases. A maximum operating bandwidth of 22.05 Hz was observed at 1.4g increasing from an operating bandwidth of 9.43 Hz at 0.4g.