Flexible Piezoelectric Polymer Membrane as Effective Tactile Sensor

We report a novel piezoelectric, flexible polymer sensor based on porous polyvinylideneflouride membrane. The piezo-membrane is prepared by the nonsolvent-induced phase separation method with water as nonsolvent. It exhibits open-circuit voltage (OCV) and short-circuit current up to 4.2 V and 1800 nA upon repetitive human finger tapping. The output performance of the piezo-membrane is correlated with the formation of electroactive polar $\beta $ - and $\gamma $ -phases in the polymer whose presence is confirmed by infrared spectroscopy and X-ray diffraction (XRD) analysis. The sensor is able to detect signals generated by finger tapping on various surfaces and when attached to the feet of a walker. The novel strategy is a step forward to enable safe, sustainable, cost-effective, flexible, and durable tactile/pedal sensors.