Comparative analysis of energy harvesting by magnetoelectric components in a simulated biological environment

Abstract

Implantable micro-electro-mechanical devices represent the most promising wearable technology for accurate and rapid monitoring of physiological parameters, as well as for delivering electrical stimulation to enhance therapeutic outcomes. However, reliance on battery power poses significant challenges, including medical risks associated with multiple surgeries for battery replacement and potential health threats from chemical leakage, which can also lead to environmental pollution. To address the demand for wireless energy supply in low-power applications, this paper proposes a wireless energy transmission technology based on the magneto-electromechanical effect (MME). By utilizing magnetostrictive and piezoelectric materials, the magnetoelectric energy harvesting component efficiently converts external magnetic field energy into electrical energy. Subsequent power management circuits enable the effective powering of MEMS devices. An experimental test system for the magnetoelectric energy harvesting component was developed. Comparative studies revealed that applying a magnetic field along the length of the components, using high-performance PMN-PT piezoelectric materials, and employing rigid packaging methods achieve the most efficient magnetic field-vibration dual-mode energy harvesting. A self-fixed high-performance magnetoelectric energy harvesting structure was then proposed, and its magnetoelectric energy conversion efficiency and power density were evaluated under simulated implantation conditions through simulation and experimentation. The results demonstrated that, under an excitation of 5 Oe AC magnetic field, a maximum power density of 345.1 μW/cm³ could be achieved with an external resistance of 200 kΩ. By leveraging the electric energy generated by the device in conjunction with a fundamental power management circuit, this research scheme successfully illuminates an Led lamps and provides power to a low-power thermometer. A key highlight of this study is the comparative analysis of various factors influencing the performance of magnetoelectric energy harvesting components. Additionally, a reliable packaging scheme and structure for use as an implantable device has been proposed, which establishes a solid foundation for future optimization of device performance.