Performance of a Lever‐Gear Type Piezoelectric Energy Harvester for Collecting Pedestrian Energy

As pedestrian‐induced energy exists widely in our daily life, the collection of pedestrian energy has attracted increasing attention. Herein, a novel energy harvester is developed to capture the kinetic energy of pedestrians. The mechanical part of the energy harvester mainly consists of a lever structure and a gear transmission component, which is used to convert the kinetic energy of pedestrians into that associated with the rotation of the device. Energy is collected by a polyvinylidene fluoride (PVDF) piezoelectric film. The performance of the harvester is tested under both indoor and outdoor conditions. Experimental results show that the maximum output voltage of the harvester with a single PVDF film is 1170 mV, and the harvester reaches the best output state when the load is 510 kΩ (acceleration 0.3 g (1 g = 9.8 m s −2 ), frequency 5 Hz) with the maximum output power equal to 1.41 μW. The harvester is then optimized by adding more PVDF films, and the improved device is found to possess a higher working efficiency, with the output voltage and power increased by 58.6% and 26%, respectively. Finally, outdoor tests are conducted, and the results further confirm the feasibility of using the device to harvest the ultralow frequency kinetic energy of pedestrians.