Flexible Capacitive Pressure Sensors and Their Applications in Electronic Skin

Pressure sensor is an important component of wearable devices, and flexible capacitive pressure sensors are the first choice because of the advantages of low impedance, low power, and high stability. The sensor that is in direct contact with the skin is called electronics skin, and its main purpose is to detect various indicators of the target group and provide feedback. To meet people's pursuit of comfortable and efficient electronic skin, new materials and technologies are adopted for flexible capacitive pressure sensors. In this paper, the function and improvement process of flexible capacitive pressure sensors and their specific application on electronic skin were reviewed. Firstly, this paper introduces the principle of flexible capacitance pressure sensor and the structure of a simple capacitive pressure sensor. Then, the preparation methods and technologies of flexible capacitive pressure sensors in recent years are summarized, mainly involving the popular three-dimensional (3D) printing technology and organic polymer materials. Finally, the application of the flexible capacitive pressure sensor in the skin is summarized, such as health inspection, environment inspection and human-computer interaction.