An Energy Harvesting Interface Based on Reconfigurable Piezoelectric Harvester Array

This paper presents a Reconfigurable Piezoelectric Harvester Array (RPA) designed for multi-input systems, which dynamically configures its structure based on the intensity of ambient vibrations. The proposed architecture enhances system efficiency by eliminating DC-DC converters and achieving Maximum Power Point Tracking (MPPT) through a single power stage. It also widens the input range by serially connecting PEH units, enabling operation at lower excitation levels. Additionally, this series connection reduces equivalent parasitic capacitance, improving flip efficiency and Maximum Output Power Improving Rate (MOPIR). The proposed RPA is employed with classical parallel-synchronous switch harvesting on inductor (P- SSHI) technology and implemented using a 180nm CMOS process. Experimental results demonstrate a conversion efficiency of up to 78%, a MOPIR of 5.93, and a minimum input voltage of 0.36V. This highly integrated, wide-input-range, and energy-efficient scheme offers a novel approach to miniaturizing PEH systems. We present detailed design principles, operational mechanisms, and performance metrics, highlighting the RPA's potential as a scalable and environmentally friendly solution for powering next-generation IoT devices.