Bioinspired PVDF Piezoelectric Generator for Harvesting Multi-Frequency Sound Energy

With the rapid development of micro-energy harvesting technology, noise has great potential as a new type of micro-energy source by developing a high-performance acoustic energy harvester (AEH). Nevertheless, the challenges of harvesting energy from noise are low acoustic energy density, multi-frequency mixed sound, and unstable sound pressure. Piezoelectric-based AEHs are proposed as a solution, but most reported devices need to work at a certain frequency and very high sound pressure, and exhibit the disadvantages of being bulky and heavy when using an extra sound-pressure amplifier. Here, the eardrum and cochlea bioinspired polyvinylidene fluoride (PVDF) piezoelectric generator which is lightweight, compact, has a simple structure and is low-cost, harvests multi-frequency sound energy. Although using the commercial pure PVDF membrane, the prepared AEH still presents a high acoustoelectric conversion performance with an output power of 8.45 & mu;W and an acoustic sensitivity of 1 V Pa-1 at 200 Hz and 100 dB without using any sound-pressure amplifier through optimizing the structure-vibration-frequency relationship. More importantly, the bioinspired AEHs do not only exhibit the ability of acoustic energy harvesting function but also have the abilities of frequency recognition and acoustic sensing, which show great potential in the application of self-powered acoustic sensors.