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A piezoelectric-based flexible magneto-electric (ME) thin film sensor has been developed for the detection of AC magnetic fields (H ac ), 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 (α ME ) 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 H ac and frequencies. Experimental results demonstrated maximum α ME 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 H ac . [ABSTRACT FROM AUTHOR]

A fully printed piezoelectric based touch sensor device has been successfully fabricated on flexible polyethylene terephthalate (PET) and paper substrates using screen printing technique. The device, consisting of a 4 × 4 array of printed sensors and interconnect lines, was fabricated using silver (Ag) ink. Screen printed polyvinylidene fluoride (PVDF), as a piezoelectric layer, was sandwiched between the printed Ag top and bottom electrode metallization layers. A linear relationship between the sensor response and varying applied forces to the device was obtained through finite element analysis (FEA) method simulation. X-ray diffraction (XRD) analysis was performed to verify the formation of the β-phase crystals in the PVDF layer during the curing process. The effective polarization of the printed piezoelectric layer was analyzed using capacitance-voltage analysis. A sensitivity of 1.2 V/N and 0.3 V/N, with correlation coefficient of 0.9954 and 0.9859, was obtained for the PET and paper based printed touch sensors, respectively. The piezoelectric-voltage analysis demonstrated that the printed sensors can be used for both touch and force based applications. [ABSTRACT FROM AUTHOR]

A novel printed strain sensor, based on metal-metal composite, was developed for applications in the biomedical and civil infrastructural industries. The sensor was fabricated by screen printing a silver nanowire (Ag NW)/silver (Ag) flake composite on a flexible and stretchable thermoplastic polyurethane (TPU) substrate in two design configurations: straight line and wavy line. The capability of the fabricated strain sensors was investigated by studying its electro-mechanical response towards varying elongations. Average resistance changes of 104.8%, 177.3% and 238.9%, over 100 cycles, and 46.8%, 141.4% and 243.6%, over 200 cycles, were obtained for the sensors with the straight and wavy line configurations at elongations of 1 mm, 2 mm and 3 mm, respectively. A sensitivity of 21% and 33%, in resistance change for every 1% strain, was calculated for the printed strain sensors with the straight and wavy line configurations, respectively. The results obtained thus demonstrate the feasibility of employing conventional addictive screen printing process for the development of strain sensors for applications that require a flexible and stretchable form factor. [ABSTRACT FROM AUTHOR]