A Flexible Capacitive Pressure Sensor Based on Microstructured Electrode and Dielectric Layer

Flexible capacitive pressure sensors based on micro/nanostructures are characterized by their high-sensitivity detection to pressure changes and conformity to complex structured surfaces, demonstrating significant potential in medical signal monitoring, intelligent human-machine interaction systems, and robotics applications. However, the development of sensors with high sensitivity, wide dynamic range, and excellent stability still remains a critical challenge. To address this, we proposed a flexible capacitive pressure sensor employing a micro structured polydimethylsiloxane (PDMS) film with doped multi-walled carbon nanotubes (MWCNTs) as the dielectric layer, and a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{3}\times \mathbf{3}$</tex> array of micro-convex AgNWs/PDMS composite structures as the electrode layer. The sensor achieved a pressure sensitivity of 0.191 kPa<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> in the range from 0 to 5 kPa, and maintains stable performance after 1000 cyclic tests. Furthermore, the sensor was validated for effectively monitoring different human joint movements. These results promised the sensor to be broadly applied in electronic skin, wearable electronics, and intelligent robotics.