Model for the Electro-mechanical Behavior of Elastic Organic Transistors*

Organic thin film transistors (TFTs) can be made with materials that allow them to be mechanically stretched during electrical operation. Circuits made with stretchable elements have uses ranging from bioelectronics to strain sensors. In practice, it is critical to understand circuit behavior in a variety of deformation modes. We describe the application of mechanical models of the elasticity of polymers to predict the electrical characteristics of elastic TFTs. The model predicts the current-voltage behavior of TFTs under uniaxial and biaxial deformation assuming stretchable elements for contacts, dielectrics, and the semiconducting layer. The behavior of complementary inverters using elastic TFTs is presented along with criteria for stable operation as digital circuit elements. The mechanical model was also applied to organic electrochemical transistors (OECTs). The behavior of elastic OECTs differs substantially from TFTs and the model predicts that they can provide benefits for the stability of simple digital circuits.