Enhancement of Energy-Harvesting Performance of Magneto–Mechano–Electric Generators through Optimization of the Interfacial Layer
So Hyeon Kim, Atul Thakre, Deepak R. Patil, Sung Hoon Park, Timothy Alexander Listyawan, Nokeun Park, Geon‐Tae Hwang, Jongmoon Jang, Kwang Ho Kim, Jungho Ryu
Abstract
Among various energy harvester paradigms, the simple cantilever-structured magneto–mechano–electric (MME) energy generator comprises a piezoelectric material laminated on a magnetostrictive metal plate and permanent magnets as proof mass, exhibiting excellent magnetic energy-harvesting performance. The current challenge in using MME energy harvesters is the mechano–electric coupling at the interface between the piezoelectric material and magnetostrictive metal layer, which depends significantly on the mechanical properties of the interfacial adhesive layer. In this study, the effects of four types of adhesive interfacial layers on the output power and environmental and fatigue resistances of MME harvesters are systematically investigated. An optimized MME energy generator with an adhesive interfacial layer of 18.8 μm thickness and elastic modulus of 3.1 GPa achieves colossal enhancement (∼300%) with a maximum output power density of 0.92 mW/cm2, while a 10 Oe (=10 G = 1 mT in air; 60 Hz) magnetic field is applied. In addition, the generator exhibits a robust endurance of continuous 108 fatigue cycles and excellent temperature stability in the range of −30 to 70 °C. The presented MME generator, which harvests stray magnetic energy reliably, is promising as a low-cost and efficient autonomous power source for Internet of Things devices, wireless sensor networks, and so on.