Analytical modeling of piezoelectric charge gated thin film transistor for force sensing and energy harvesting

This paper addresses a novel electronic device that works in force sensing and energy harvesting dual modes. It combines a dual-gate thin film transistors (TFT) and a thin film piezoelectric material. In force sensing mode, the thin piezoelectric film is placed atop TFT and works as a top gate. That top gate voltage which is induced by the applied force will affect the output current of TFT. An analytical model is given to elaborate how output current varies with applied force. Energy harvesting mode can be achieved by simply connecting the top, bottom gates and the drain terminals that will make TFT work in the saturation region without any other external power supply. A detailed analysis on working principle and numerical study is conducted to evaluate its theoretical energy generation in one cycle with various forces.