A high efficiency standalone magnetoelectric energy converter based on Terfenol-D and PZT laminate

Abstract

Magnetoelectric energy converters are specific energy converters that utilize the magnetoelectric effect to generate an electric polarization response to an applied magnetic field or, conversely, a magnetization response to an electric field. Prior studies reported magnetoelectric energy converters with an efficiency of more than 80%. However, these converters require DC magnet bias to achieve such a high efficiency and bulky electromagnetic magnets or Helmholtz coils were utilized to provide the DC magnet bias, which limits their applications in portable electronics, internet of things, or medical applications. In this paper, a standalone magnetoelectric energy converter that does not require a bulky DC magnet field is presented. It is based on a tri-layer of Terfenol-D (TbDyFe2) and lead zirconate titanate. A measured high energy conversion efficiency of 88% and a small volume of 1.356 cm3 are demonstrated when operating at its fundamental mechanical resonance frequency of 34.6 kHz. The factors that affect its efficiency are discussed including tri-layer thickness ratio, operation frequency, and load resistance. The energy converter based on the magnetoelectric effect with a high efficiency and small volume could have potential applications in portable electronics, internet of things systems, and wireless charging.