Magnetoelectric current sensor

Magnetoelectric (ME) composites can directly generate an electric signal in response to the applied external magnetic field, leading to a passive sensing without the need of external power sources. In addition, by optimizing the composite material composition and configuration, one can realize significantly large voltage and sensitivity over a wide range of frequency. These considerations are driving the development of ME composites for passive sensing devices, especially on the current/magnetic field sensing. In this chapter, we will systematically describe the development of magnetoelectric current sensors with respect to challenges of typical ME composite systems, novel sensor designs, and their working mechanisms. Self-biased ME composites that can provide a giant ME coefficient at zero bias will be introduced and their application toward current sensors will be discussed. Further, ME transformers that can provide a tunable voltage gain and/or resonance frequency under a magnetic field will be illustrated. Lastly, the identification of a magnetic noise source and corresponding noise reduction methods will be discussed to achieve better detection sensitivity over a wide range of frequencies.