Harnessing energy from micro vibration using smart materials

Abstract

Energy harnessing for the purpose of powering low power electronic devices has received much attention in the last few years. By harnessing ambient energy from the environment it will eliminate the need for batteries and supplying the portable electronic devices such as cell phones, laptops and MP3 players with infinite amount of energy. The ambient energy that can be harnessed to generate electricity comes from a wide range of sources but vibration energy shows a promising amount of power generation. In this study, conversion of mechanical vibration into electricity using piezoelectric vibration-to-electricity converter is undertaken with a focus to quantify the amount of power that can be generated and identify electronic devices that can fully utilize this power. The study is divided into two main parts which are simulation from the forced vibration data and laboratory experiment on vibrating mechanical equipments such as turbine and centrifugal pump. The simulation result shows that as the acceleration magnitude increases, the average direct voltage also increases from 4.5 mV to 8.1 mV and the average power output that could be harnessed also increases from 22.5 µW to 40.5 µW. Similarly, the experimental result shows that for the turbine, as the speed of the turbine increases from 1150 rpm to 1450 rpm, the average power produced increases from 1.63 µW to 2.02 µW. Also, for the centrifugal pump, as the speed increases from 1700 rpm to 1900 rpm, the average power produced increases from 3.02 µW to 3.06 µW. The experimental results also revealed that within 30 minutes, 1.84 µW of energy could be harnessed from the vibration of the turbine at speed of 1450 rpm while 3.06 µW of energy could be harnessed from the vibration of the centrifugal pump at speed of 1900 rpm. This power output is sufficient for low-powered wireless sensor networks in silent mode which can be used in variety of applications as indicated in the previous literatures.