Fabrication of Flexible Double-Gate Organic Thin Film Transistor For Tactile Applications

In this work, the development of a flexible Double-Gate (DG) organic thin film transistor (DG-OTFT), and its employment is reported for the realization of multimodal tactile sensors. Due to the self-encapsulation of the stacked DG architecture, highly stable organic transistors are obtained that show almost negligible degradation after 6 months. Moreover, such configuration is also very useful for the development of sensing devices. In the case, one of the two gates is used to bias and set the working point of the devices, whereas the second one is connected to a polyvinylidene fluoride(PVDF)-capacitor, a pyro/piezoelectric material. It is demonstrated that the charge displacement induced by the PVDF capacitor due to an applied external pressure or due to a temperature variation led to a reproducible variation of the device's output current. Using this approach high-performing multimodal tactile sensors are obtained with sensitivity to up to 241 nA N−1 and 442 nA °C−1 respectively.