[26a-F407-1~4] 16.2 Energy Harvesting

▲ [26a-F407-2] ZnO thin films on flexible stainless-steel foils for energy harvesting application

〇VANMINH LE¹, FENG HAO¹, HIROKI KUWANO^1,2 (1.Tohoku University, 2.Sendai Smart Machines)

Keywords:piezoelectric energy harvester, piezoelectric thin films, piezoelectric device

In this research, we developed ZnO thin films on flexible stainless-steel (SUS) foils for vibration-driven energy harvesters. The films were grown using a reactive radio frequency (rf) magnetron sputtering deposition in Ar/O₂ ambient. The impact of stainless-steel surface roughness on the c-axis orientation was investigated. Decreasing the surface roughness enhanced significantly the full-width at half maximum (FWHM) of the X-ray rocking curve. Also, the films were implemented for fabricating the energy harvester device with a cantilever and a proof mass. The power characteristics show that the device had a power of 50 uW at an acceleration of 9.8 m/s². The power density of 0.085 uW.g².mm^-3 was 85 times larger than our previous result of ZnO/non-polished SUS-based energy harvester.