Electrical responses of piezoelectric device

Energy harvesting from human motion by using piezoelectric element plays an important role in the development of renewable energy technology. The energy harvesting mechanism includes the process of extracting the renewable energy, converting it into usable electricity and then storing the energy as in capacitor. Piezoelectric element is used as a sensor to convert mechanical energy into electrical energy. The electrical power supply can be used for electronic devices and other mobile applications. The element is capable in converting mechanical energy from the motion of human body, such as walking and running activities, into electrical energy. In this research, a prototype of piezoelectric energy harvesting was developed. Piezoelectric disk-type sensor was installed inside a shoe of officer cadets to harvest the mechanical force from the walking motion. The experimental work was tested for five different weights (48 kg, 59 kg, 62 kg, 71 kg, and 85 kg) of officer cadets on the treadmill with a constant speed of 2 km/h. The piezoceramics material used in this research was lead zirconate titanate (PZT). Before the piezoelectric device was tested on the cadets, the effects of single impact (free fall) of different weights (1N, 2N, 3N, 4N, and 5N) on PZT piezo disk were tested and analyzed. The responses of piezoelectric element were analyzed. The results show that the piezoelectric device generates a maximum output voltage of 7.4 V from the walking movement.