Tactile sensors with integrated piezoelectric polymer and low voltage organic thin-film transistors

This paper presents a novel approach for realizing tactile sensors by integrating a piezoelectric polymer with a low voltage Organic Thin-Film Transistor (OTFT) on flexible plastic substrates. The transducing element consists of PVDF piezoelectric film. The proposed device architecture is similar to the extended gate scheme, whereby the transducing material is connected to OTFT via extended gate. In this scheme, the OTFTs and the transducer material may be or same substrate, as in this case, or they may be on different substrates. The piezoelectric effect induced by an external mechanical stimulus modulates the output current of the OTFT. This scheme represents a simple and innovative solution for artificial sense of touch and is particularly suitable for the low-cost fabrication of so-called "electronic skin". The electromechanical characterization shows that the sensing devices can detect forces stimuli within the range 0.5 - 8N.