Large-area stretchable organic transistor integrated circuits for sensor and display applications

Abstract

Stretchability significantly expands the scope of electronic applications-particularly large-area electronics such as displays, sensors, and actuators-because stretchable electronics can cover arbitrary surfaces and movable parts, which is impossible with conventional electronics. However, the realization of stretchable electronics for the manufacturing of electrical wiring with high conductivity, high stretchability, and large-area compatibility is a major hurdle. We manufactured printable elastic conductors comprising single-walled carbon nanotubes (SWNTs) uniformly dispersed in fluorinated rubber. Using ionic liquid and jet milling, we produced longer and finer SWNT bundles that formed well-developed conducting networks in rubber. A conductivity and stretchability greater than 100 S/cm and 100%, respectively, were obtained. In order to demonstrate the feasibility of the elastic conductors for electrical wiring, we manufactured a rubber-like large-area organic transistor active matrix comprising printed organic transistors and elastic conductors. The effective area of the matrix was 20 × 20 cm 2 . The active matrix sheet was uniaxially and biaxially stretched to 70% without incurring mechanical or electrical damage. Furthermore, we constructed a rubber-like stretchable active matrix display comprising integrated printed elastic conductors, organic transistors, and organic light-emitting diodes. The display could stretch by 30-50% and spread over a hemisphere without being mechanically or electrically damaged.