Printed Strain Sensor with High Sensitivity and Wide Working Range Using a Novel Brittle–Stretchable Conductive Network
Yifei Wang, Tomohito Sekine, Yasunori Takeda, Jinseo Hong, Ayako Yoshida, Hiroyuki Matsui, Daisuke Kumaki, Takao Nishikawa, T. Shiba, Tadahiro Sunaga, Shizuo Tokito
Abstract
There are few reports on resistive strain sensors that exhibit both high sensitivity and a wide working range under stretching. We have newly developed a high-performance strain sensor based on a brittle-stretchable conductive network that consists of both brittle and stretchable conductive layers and is fabricated on a stretchable substrate using the screen-printing method. Adding strain usually generates structural cracks in brittle conductive layers leading to a significant increase in resistance, while a stretchable conductive layer bridges these cracks to maintain the conductive pathways under high-strain conditions. This novel conductive network endows superior electrical-mechanical performance to the strain sensors, which possess high sensitivity (gauge factor > 870) over the entire working range (∼100%). Additionally, the developed sensors showed unique anisotropic bend-sensing characteristics, which could be used to detect the bending directions. This high degree of comprehensive performance results in a strain sensor with the capability for full-range human motion detection and robotic motion sensing.