A Flexible Piezoelectric Energy Harvesting System for Broadband and Low-frequency Vibrations

A piezoelectric energy harvesting system, where elastomer pillars stand on a piezoelectric polymer layer is designed, fabricated and tested for low and broadband frequency vibrations. In this configuration, elastomer pillars behave like a set of oscillators on the vibrating structure, which provide absorption of vibration energy and act as an energy sink. Then, the stored elastic energy is converted to electrical energy in the clamped boundary via stress concentration on the piezoelectric layer. A single pillar system with 10 mm diameter and aspect ratio of 3 with an active area of 39 mm2 and thickness of 28 μm generate a voltage of 4.5 V and an output power of 58.4 μW for an input acceleration of 3 g at 62 Hz with optimized load resistance condition.