Highly Sensitive Wearable Piezoelectric Force Sensor With Quasi-Static Load Testing

This paper proposes the development of a wearable piezoelectric sensor from polyvinylidene fluoride (PVDF) that can be integrated into clothing and measure high forces. Based on the direct piezoelectric effect, good linearity is expected such that there should be an increase in voltage as higher loads are tested. With external circuitry and an interface to a computer via a microcontroller board, measurements include calculations for initial voltage, force, pressure, and normalized voltage as well as measured voltage. Results are analyzed based on two criteria: first, wearable conditions based on no-cloth, rigid-cloth, and smooth-cloth implementations; and second, the maximum force applied by varying sensor dimensions. Two load ranges were also applied: low-force threshold between 2.5 and 10 kN with steps of 0.5 kN and high-force threshold between 10 and 50 kN with steps of 2.5 kN. Given this criteria, all results that have shown great accuracy can be attained, since all percent errors are within the performance error threshold between 2% and 5%.