Reverse Electrowetting-on-Dielectric (REWOD) Energy Harvesting Circuit Advancement for Improved Power Conversion Efficiency

Over the past decade, several technologies have been proposed to harvest electrical energy from mechanical energy using activities motioned at lower frequencies. However, the generated energy needs to be modulated into a suitable signal to harvest energy efficiently and use it effectively in an application. This paper presents advancements of active circuitry for the reverse electrowetting-on-dielectric (REWOD) energy harvester method. The proposed active circuitry includes a rectifier, a DC-DC converter, and a charge amplifier. The harvested energy is transformed into a DC supply using the proposed rectifier and is maintained at the required constant voltage by implementing a DC-DC converter. The REWOD-generated charge, which is typically very low, is amplified by implementing a charge amplifier improving the signal-to-noise ratio (SNR) providing a gain of 2 V/V and transmitted remotely to a digital receiver. Further, to avoid power flickering or disruption, the filter circuit of the rectifier is integrated with a super-capacitor, maintaining a constant power supply for 5 minutes with a power conversion efficiency (PCE) of more than 80% at 1 Hz. The proposed circuitry is suitable for powering small devices such as wearable body sensors for biomedical applications.