Flexible Interfacial Capacitive Pressure Sensor Based on Randomly Distributed Micro-Pits Electrode

Pressure sensors are regarded as an important part of flexible electronic devices. However, the sensitivity of capacitive pressure sensors is relatively low to obtain distinct and stable signals along with a high signal-to-noise ratio. Interfacial capacitive pressure sensor, which has a large initial capacitance due to the formation of an electric double layer (EDL), is more resistant to interference. Herein, the deformation of the micropits structure in electrode under external stimulus is proven to be helpful for improving the performance of the pressure sensor. Using sandpaper as a random microstructure transfer template, an interfacial capacitive pressure sensor based on random micro-pit structure carbon electrodes was prepared. The electrical performance of the electrode is inferred to be an important factor in achieving excellent properties. The proposed device exhibits long-term durability over 8000 cycles, low detection of a limit of 1.7 Pa, and a fast response time of similar to 30 ms. The applications of these pressure sensors in sensing pulses, acoustic vibration, and human motion are demonstrated, exhibiting their great potential use in healthcare monitoring, motion detection, and tactile sensing.

Automated summary

This paper introduces an interfacial capacitive pressure sensor based on a carbon electrode with a micro-pit structure. By improving the electrical performance of the electrode and utilizing the deformation of the micro-pit structure under external stimulus, the performance of the pressure sensor is enhanced. The proposed device exhibits long-term durability, low detection limit, and fast response time, demonstrating great potential applications in healthcare monitoring, motion detection, and tactile sensing.