Highly Reliable Physical Bending Sensors using Heterostructured Floating Gate Organic Transistor

Abstract

Herein, a piezovoltage-modulated field-effect transistor (PVMFET) is proposed that provides physical sensing capabilities while maintaining excellent FET performance through the combination of a piezovoltage (PV) capacitor sensing medium and an FET structure that can amplify signal responses to external stimuli. The PV generated in the piezoelectric poly(vinylidene fluoride)-co-trifluoroethylene-based PV capacitor through bending deformation modulates the effective gate voltage induced in the PV-modulated gate. In particular, in the device, it is found that the piezo-responsive modulation of the effective gate electric field is enhanced by the applied gate voltage, corresponding to the higher modulation of channel current at the higher gate voltage under bending. Accordingly, a PVMFET-based physical sensor that can accurately estimate the bending angle is implemented. The sensor exhibits a high sensitivity, repeatability, and a sensing linearity of 0.98 while the bending angle is varied from 0 degrees to 93 degrees. The sensing performance remains constant even when the bending frequency changed from 0.25 to 1.0 Hz at the largest bending angle (93 degrees) measured, confirming the effectiveness of the sensor platform. The proposed PVMFET-based physical sensor platform is suitable for applications that require stable driving performance and the simultaneous detection of external physical stimuli in real time.