Evaluation of Metglas/polyvinylidene fluoride magnetoelectric bilayer composites for flexible in-plane resonant magnetic sensors

Abstract

Flexible magnetic sensors are attracting more and more attention because of their application in wearable devices. In this paper, Metglas/polyvinylidene fluoride (PVDF) bilayer composite with good flexibility was fabricated to evaluate its applicability as a flexible in-plane magnetic sensor. The magnetoelectric (ME) coupling characteristics and sensing performance of the sample were investigated under different test conditions, including different AC and DC magnetic field, and changing the direction of the magnetic field and the bending degree of the sample. The sample shows a large ME coefficient with a value of 176.41 V cm−1 Oe. The sensitivity, linearity and deviation of the sample are 892.96 mV Oe−1, 0.99965 and ±2% for the AC magnetic field, and 157.6 mV Oe−1, 0.99444 and ±5% for the DC magnetic field, respectively, and it shows excellent stability over repetitions. Moreover, the sample was gradually rotated anticlockwise in the magnetic fields. The output voltage of the sample varies with the rotation angle and has a good symmetry in plane, which is described well by a sine function. In addition, the clamping effect of the sample was studied. Even when bent, the sample still maintains an excellent and stable performance. The sensitivity and linearity of the sample with a bent angle of 23.5° are 254.37 mV Oe−1 and 0.99975 for the AC magnetic field, and 28.07 mV Oe−1 and 0.99309 for the DC magnetic field, respectively. The deviation of measurements is small for both the AC and DC magnetic sensors. In summary, the present study shows that the Metglas/PVDF bilayer composite has a good sensing performance and is suitable for = flexible in-plane resonant magnetic sensors.