Flexible acetylene black/PDMS capacitive pressure sensor with enhanced sensitivity based on percolation principle

Recent advances in soft materials have provided a great opportunity for the development of flexible electronics. This study proposed a novel capacitive pressure sensors with enhanced sensitivity by adopting the materials of acetylene black and polydimethylsiloxane (PDMS). Based on the percolation principle, spacing of conductive particles, which closely associated with sensing performance, were adjusted by controlling the concentration of filled acetylene black and its curing time with PDMS. An optimized acetylene black/PDMS capacitive pressure sensor was finally fabricated achieving a sensitivity of 0.248 kPa⁻¹ in the range of 4-50 kPa which is nearly five times higher than that of the pure PDMS sensor. Additionally, this developed soft sensor also present a quick response time and excellent stability that may have great potential to be applied in wearable and real-time monitoring. Furthermore, this systematical investigation and optimization towards material processing techniques may provide evidence-based guidance for the improvement of soft material-based capacitive pressure sensors.