POSFET Devices Based Arrays For Tactile Sensing

This work presents and evaluates the novel POSFET (Piezoelectric Oxide Semiconductor Field Effect Transistor) devices based tactile sensing arrays primarily developed for the robotic applications. The tactile sensing arrays, consisting of 5 x 5 POSFET touch sensing devices or taxels, are developed by spin coating and processing ~ 2.5 μm thick piezoelectric polymer P(VDF-TrFE) (Polyvinylidene Fluoride-Trifluoroethylene) film on the gate area of MOS devices. Each taxel on the array utilizes the change in polarization level (and hence change in the induced channel current), as a result of contact forces, to detect the contact events. Both the taxels and the array are designed to match spatio-temporal performance of the human fingertips. The POSFET tactile sensing arrays presented here are able to detect complex dynamic contact events such as rolling of an object over a surface.