A screen printed and flexible piezoelectric-based AC magnetic field sensor

A piezoelectric-based flexible magneto-electric (ME) thin film sensor has been developed for the detection of AC magnetic fields (Hac), at room temperature. The sensor was fabricated by screen printing piezoelectric-based polyvinylidene fluoride (PVDF) ink on flexible and magnetic Metglas® substrate. 3D interferometry and X-ray diffraction (XRD) was used to characterize the profile and crystalline contents, respectively of the printed PVDF film. The top electrode was fabricated by depositing silver (Ag) ink on the printed PVDF layer using bar coating technique. The theoretical results demonstrated ME voltage coefficients (αME) of 84.5 mV/cmOe and 56.5 mV/cmOe for Metglas®/PVDF composite at cross-sectional area (n) of 0.12 (longitudinal direction) and 0.15 (transverse direction), respectively. The performance of the fabricated ME printed sensor was investigated by measuring the induced voltage response towards varying Hac and frequencies. Experimental results demonstrated maximum αME of 685.99 V/cmOe, at electromechanical resonance of 50 kHz. The result also demonstrated a linear relationship with a sensitivity of 503.3 V/T and correlation coefficient of 0.9994 towards varying Hac.