Nanofillers embedded flexible piezoelectric polymer sensor pad for robotic and human finger tap analysis

Abstract

Flexible pressure sensors are receiving a lot of attention due to their use in wearable electronic devices, human-machine interactive systems, and physiological signal monitoring. In this paper, we present a novel nanofiller embedded thin film based piezoelectric pressure sensor for finger tapping analysis. The active material is fabricated using poly (vinylidene fluoride) (PVDF) having zirconium oxide (ZrO2) nanofillers. It is observed that the incorporation of ZrO2 nanofillers has a substantial impact on the structural characteristics of PVDF polymer, leading to enhancements in its piezoelectric properties. Moreover, the PVDF/2 wt% ZrO2 composite film sensor showed a notable maximum piezoelectric output voltage of ∼210 millivolts at a load of 20 g (0.88 kPa applied pressure). A four-fold enhancement in response is observed in case of PVDF/2 wt% ZrO2 composite in comparison to pristine PVDF sensor. Further, a sensitivity of 0.255 ± 0.083 kPa−1 has been recorded for the composite based sensor. Additionally, maximum of 115 mV is obtained when the composite sensor is tapped manually. The recorded maximum values for impulsive pressure (38 g), high pressure (108 g), and low pressure (45 g) are 76 mV, 150 mV, and 90 mV, respectively. The sensor is efficiently able to detect robotic tapping and stress on the human fingers. An efficiency of around 90% was achieved in PVDF/ 2 wt% ZrO2 at 5 kV/cm using PE hysteresis loop data. The findings indicate that PVDF/ZrO2 composite based piezoelectric pressure sensor has promising capabilities for applications in wearable electronic devices and medical diagnostics.