A Low Conductivity Medium Detection Module Based on Magnetoelectric Sensors

Magnetic induction tomography (MIT) has the advantages of being non-invasive, non-contact, and low-cost, and is widely used in multiple fields and the biomedical field. However, most traditional MIT systems use detection coils as magnetic field sensors, which have low detection sensitivity, magnetoelectric (ME) sensors composed of magnetostrictive materials and piezoelectric materials have the advantages of high sensitivity, wide bandwidth, and small volume. In this paper, a double excitation coil eddy current magnetic induction detection model used for MIT system is established. The variations of the excitation magnetic field, the induced magnetic field, and the phase shift with the thickness and conductivity of the saline are numerically calculated. A low conductivity medium detection module with a minimum magnetic field detection limit lower than 20 pT in the range of 15 MHz - 30 MHz is constructed using a ME sensor, its phase shift noise is lower than (6×10⁻⁵)°, the conductivity and volume changes of the saline are detected. This double excitation coil eddy current magnetic induction detection model based on ME sensors has high sensitivity, low phase shift noise, and small volume, providing a fresh perspective for MIT biomedical imaging.