Mechanical-field-coupled thin-film transistor for tactile sensing with mN dynamic force detection capability and wearable self-driven heart rate monitoring with μW power consumption

We present a mechanical-filed-coupled thin-film transistor (TFT) intended for mechanical sensor applications. To apply the mechanical field to the TFT, a polyvinylidene fluoride (PVDF) piezoelectric transducer is vertically integrated with an amorphous silicon (a-Si:H) TFT to form a dual-gate TFT where its top gate is coupled with the mechanical field, its bottom gate is to tune the working regime, and its channel layer is in three-dimensional shape for achieving high sensitivity. We have demonstrated its applications in a tactile sensor with high sensitivity that can detect a gentle dynamic touch down to mN and a wearable piezoelectric self-driven heart rate monitoring device with only μW-range power consumption.