Pressure dependent current-controllable devices based on organic thin film transistors by soft-contact lamination

Soft-contact lamination is a versatile technology for fabricating unconventional electronic devices, and also imparts an efficient functionality to organic thin film transistors (OTFTs). In this study, a pressure sensor based on this technique was fabricated using an elastic polydimethylsiloxane (PDMS) mold with gold (Au) electrodes. Since the effective channel length of the laminated OTFT could be controlled by external pressure on the structured PDMS mold, the changes in source-drain output currents also corresponded to the external loads without any change of the material properties. Owing to the elastic properties of the PDMS mold, the laminated device returned to its former structure after the external pressure was released. Based on this device property, reversible and time-durable operations of the device were demonstrated.