A dual-output full-wave rectifier-based power management circuit with a synchronized input switch for triboelectric nanogenerators

Abstract

Triboelectric nanogenerators (TENGs) have emerged as a promising power solution for autonomous sensors, as they can be constructed using low-cost, lightweight, and environmentally friendly materials. However, the design of the ensuing power management circuit (PMC), intended to maximize energy extraction from the TENG, remains a challenge for circuit designers at both board and integrated circuit (IC) levels, especially due to the unique properties of the TENG output signal. Among the different circuit topologies proposed in the literature, this article focuses on the full-wave rectifier (FWR) with a dual output (DO). It is proposed to incorporate a switch at the input of the FWR-DO to increase the energy extracted from the TENG. The switch is instantaneously closed in synchronization with the maximum and minimum separation between electrodes, thereby generating a short circuit across the TENG. As a result of this short-circuit, the voltage at the two outputs of the FWR-DO can be adjusted independently to optimize energy extraction in both half cycles, which is not possible in conventional FWR-DOs. The proposed circuit, including the synchronized input switch, is evaluated theoretically, by simulations, and experimentally using an in-house fabricated TENG with a contact-separation topology. Additionally, its performance is compared with that obtained using conventional FWR and FWR-DO topologies. According to the results reported herein, the incorporation of the synchronized input switch generates an improvement in the energy extraction that depends on the symmetry of the voltage-charge plot related to the TENG. For the TENG under test, the energy improvement factor (with respect to FWR-DO) is 18% when the switch is incorporated.