Cord Woven Fabric as Dielectric of a Low-Cost Wearable Capacitive Pressure Sensor for Record of Pressing Behavior at Emergency Rescue

Recently, flexible sensors with high sensitivity, good stability, and simple structure have received lots of attention for their highly wearable advantages when used in the signal acquisition community. However, solving their industrial preparation is a huge problem at this stage. In this work, a flexible and wearable fabric dielectric-based structure of high-sensitivity capacitive pressure sensor is proposed tentatively to solve the problem. First, a unique fabric dielectric layer has been fabricated based on the cord weave pattern for high elasticity. Then, the fabric was tailored to be encapsulated with supra-thin polydimethylsiloxane (PDMS) films on both sides with separated conductive fabric electrodes to form a flexible capacitive pressure sensor. The experimental results showed that the sensor exhibited superior sensitivity (0.049 kPa $^{-{1}}$ ) under the pressure of 100 kPa, a wide measuring range of 50 kPa, and an extremely low hysteresis deviation. With the PDMS packaging, the sensor displayed high durability and repeatability. The sensor response time (250 ms) is highly consistent under 100 kPa and 3000 times of cyclic compressions, with good rebound and relatively stable response abilities. The fabric weaving, PDMS packaging, and electrode assembling processes indicate the sensor capable of large-scale production. Eventually, a set of successful application demos, like monitoring of pressing human chest, were applied using the sensor on an intelligent overcoat. Thus, the sensor is expected to be used in wearable monitoring devices to provide more accurate data to support cardiac resuscitation.