Thin Film Magnetoelectric Sensors Toward Biomagnetism: Materials, Devices, and Applications

Since the discovery of strong magnetoelectric (ME) coupling in two-phase ME laminate composites, strain mediated ME heterostructures have found practical applications in magnetic sensors, tunable inductors, tunable filters, miniaturized antennas, magnetic memories, and nanoscale motors. Thin film ME sensors, in particular, have become promising candidates in biomagnetic sensing, due to their high sensitivity, CMOS compatibility, room temperature operation, and high spatial resolution. In this article, an overview is presented on different types of thin film ME sensors and their applications in biomagnetic measurement. First, the coupling structures, materials selection, and fabrication processes are introduced. Three different mechanisms of recently emerged ME sensors, including the magnetic modulation, electrical modulation, and delta-E effect are presented. Their performance and noise analysis are also compared and discussed. Finally, real-time applications of ME sensors in the detection of magnetic fields from different part of human body are presented and discussed. The review concludes with an outlook on future perspectives and challenges of thin film ME sensors for biomagnetic applications.