The Effect of Piezoelectric Shape on Energy Harvesting Shoes

Piezoelectric elements are commonly installed in shoe sole to make use of the piezoelectric effect due to the vibration generated by the human motion. Piezoelectric shoe is a great device that can be used to harvest energy and can be improved by adding more piezoelectric elements and providing storage to store the harvested energy. However, not many researchers focus on the analyzation of piezoelectric elements’ shape that may affect the efficiency of energy harvesting. In this paper, piezoelectric energy harvesting shoes are designed with piezoelectric elements installed inside the soles of the shoes, thereby gaining mechanical energy from user while walking and running. The mechanical energy was applied to the piezoelectric elements and converted into electrical energy. Bridge rectifier was used to convert the AC voltage output into DC voltage. The project focused on analyzation of the efficiency between round and square shaped piezoelectric elements. Different shape of the piezoelectric element produced different amount of output voltage. Square shaped piezoelectric tended to produce lesser output voltage than the round piezoelectric element. A round piezoelectric with diameter of 4.5cm produced mean output voltage up to 11.56V and square piezoelectric with size of 4.5cm x 4.5cm produced 6.12V. However, this all depended on how much pressure that was applied onto the piezoelectric elements.