Enhancement of Energy-Harvesting Performance of Magneto–Mechano–Electric Generators through Optimization of the Interfacial Layer

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.

High-performance magneto-mechano-electric generator through optimization of magnetic flux concentration

“…), we focused on the stray magnetic eld that ubiquitously exists around infrastructure. [7][8][9][10][11] It includes periodic magnetic elds generated by current-carrying cables as well as non-periodic magnetic elds generated by vehicles and geomagnetism.…”

“…The periodic stray magnetic eld around current-carrying cables has a constant low frequency of 50/60 Hz, which is suitable as an ambient energy source for powering smart things. [7][8][9][10] This periodic magnetic energy can be harvested using one of the most promising harvesting technologies based on magneto-mechano-electric (MME) generators. It can generate electrical charge from the mechanical stress that comes from the periodic magnetic eld.…”

“…16,17 Furthermore, additional output power is added by their synergistic effect. 5,9,18 The output performance of the MME generators was further improved by modulating the structure and geometry of the device and the material properties of its constituent layers. For example, an output power of approximately 680% was improved by tailoring the geometry of the cantilever beam from conventional rectangular to truncated shape.…”

High performance of polycrystalline piezoelectric ceramic-based magneto-mechano-electric energy generators

“…In recent years, the Magneto-Mechano-Electric (MME) energy generator has shown excellent potential for low amplitude magnetic field to electrical energy conversion. [12][13][14][15][16][17] The typical MME generator is a cantilever structure comprising a magnetoelectric (ME) composite structure of piezoelectric and magnetostrictive layers and permanent magnets as proof mass [11,12]. The basic factors contributing to the output electrical performance are magnetoelectric (ME) effect, magnetic flexural torque from the magnetic proof mass and their synergetic interaction under externally applied magnetic field [15].…”

“…Significant improvements in the output performance of the MME generators have been achieved in recent years by exploiting the various constituents of the device, such as employing low-loss anisotropic piezoelectric single crystal, textured giant magnetostriction materials, the introduction of magnetic field concentrator, optimization of device dimensions, optimization of the interfacial adhesive layer, etc [13][14][15]18,19]. Especially, the material properties of the piezoelectric layer in MME generator plays a crucial role in its energy harvesting performance.…”