Publication

Abstract : Flexible capacitive pressure sensors are increasingly important for applications in wearable electronics, healthcare monitoring, and human–machine interfaces. Despite significant progress, many flexible capacitive pressure sensors rely on complex fabrication or exhibit poor mechanical durability, limiting their practicality in real-world applications. In this work, a simple capacitive pressure sensor is developed using an array of potassium chloride (KCl)-modified polydimethylsiloxane (PDMS) microcylinders as the dielectric layer. The effects of microcylinder geometry and membrane thickness on sensing performance are systematically investigated. Numerical studies were performed to evaluate varying extents of deflection caused by different microcylinder geometries. Based on these results, a design of experiments (DoE) approach was employed to guide the fabrication of moulds with optimized parameters using high-precision computer numerical control (CNC) milling. Among the tested dielectric configurations, the KCl-modified PDMS microcylinder array exhibited the best performance, achieving a high sensitivity of 0.1047 kPa⁻1 over a range of 0.1–10 kPa, a detection limit of 0.244 Pa, and excellent durability over 10000 loading–unloading cycles. The practical utility of the sensor was demonstrated through reliable detection of sign language gestures, touch inputs, and human motion, highlighting its potential for next-generation wearable and interactive devices.