Flexible pressure sensor based on graphene/PS microsphere/PDMS composite dielectric layer and activated carbon non-woven fabrics

• Fabrication of ultra-thin dielectric layers with surface microstructures and filler doping. • Offering new ideas for improving the sensitivity of flexible capacitive sensors. • Activated carbon non-woven fabrics are used to make flexible electrodes. • New dielectric layer fabrication process developed. • A number of dynamic tests have been completed using this sensor. With the widespread application of wearable devices, the demand for high-performance sensors has increased dramatically. This study proposes a novel capacitive sensor. By using polystyrene (PS) microspheres and the sacrificial layer method, the ultrathin dielectric layer with surface micro-dome structure and uniform graphene doping are fabricated. In addition, the activated carbon non-woven fabrics (ACNWF) electrode was prepared, and the device characteristics of the sensor were investigated. The sensor has a good capacitive response in a wide pressure range (0–150 kPa) and a sensitivity of 0.209 kPa −1 in the low-pressure range. The short response time (<25 ms) is suitable for real-time dynamic monitoring. Meanwhile, the sensor has good stability (3500 cycles) and performs well in mouse double-click, muscle contraction and arm swing. This sensor has great potential in wearable electronics and human-computer interaction.