Fabrication of Organic Strain Gauge on Curved Surface by Direct Patterned Microcontact Printing for Nail Sensing

The organic flexible electronics is an attractive research due to which the wearable human sensing devices are on human fingernails distortion using functional organic materials. Generally, the strain gauge for human sensing is formed on plastic films. Therefore, while fixing the film sensor on a curved surface, such as human nails, it is difficult to make good contact. In this study, we proposed a process, which forms a patterned film of PEDOT:PSS (Poly(3,4‐ethylenedioxythiophene):Poly(4‐styrenesulfonate)) on a 3D‐curved plastic substrate by the micro contact printing method. Moreover, we fabricated a strain gauge on a flexible polyimide substrate and measured static electrical characteristics. It enables to form a patterned film on surfaces, such as human nails, and fabricates a strain gauge directly. The results show that directly printed PEDOT:PSS films on curved surfaces can be used to strain sensor, which leads to monitoring the human body by sensing of human nail anytime.