A PVDF-based piezoelectric energy harvester with high power density via displacement amplification mechanism for pneumatic exhaust recovery

Piezoelectric energy harvests (PEHs) based on PVDF polymers have recently become a research hotspot due to their excellent flexibility and fatigue resistance. However, the lower power output compared to PZT has always been a challenge that has restricted its practical application. In this study, we designed and demonstrated a high-performance pneumatic piezoelectric energy harvester (PPEH) based on PVDF polymer. The PPEH utilizes a compact lever-type displacement amplification module with an amplification ratio of 6:1, enabling large bending deformations at small stroke displacements. The PPEH with one piezoelectric unit can output peak, average, and DC power of 25.85 mW, 2.07 mW, and 1.17 mW at 10 Hz, respectively. The power generation effect is significantly improved by grouping and increasing the gap distance between the groups. When four piezoelectric units are connected in parallel, the PPEH can output 2.50 mW DC power and 30.63 mW peak power, respectively. The volume power density calculated by PPEH with a compact structure can reach 85.78 W/m³, considerably higher than other related studies. Finally, we use the PPEH to successfully power electronic devices such as magnetic limit switches of cylinders in a pneumatic environment. The proposed work can provide critical guidance and references for the high power output of PVDF polymers and expand the practical application of PVDF polymers in energy harvesting.