A Fully-Stretchable and Highly-Sensitive Strain Sensor Based Liquid-State Conductive Composite

Abstract

There is a growing demand for wearable electronic devices in recent years. In particular, stretchable strain sensors with large strain range, high sensitivity, good linearity and remarkable stability have attracted much attention in wearable electronics field for applications in the real-time human motion detection. However, the simultaneous realization of high stretchability and good sensitivity is still a critical challenge, especially in the consideration of the conformability on the curved surfaces. In this work, a fully-stretchable and highly- sensitive strain sensor with outstanding profile conformability was developed by using a novel liquid-state conductive composite composed of carbon nanotubes and liquid silicone rubber. This liquid-state conductive composite exhibits a remarkable stretchability and stability compared with traditional stretchable electrodes, which endows the strain sensor a 400% length deformation with a gauge factor of 43.84. Moreover, the proposed strain sensor was systematically studied and proven to possess the unique features of high linearity, low hysteresis and good stability. The strain sensor can endure various mechanical deformations without any damage, including 4-folded, and 360° twisted. It was also demonstrated that the developed sensor can monitor the gesture and motion of joint activities, which shows an attractive future vision for applications in health detection.