Superior performances via designed multiple embossments within interfaces for flexible pressure sensors

Ultrahigh sensitivity and wide detection range are critical for flexible pressure sensors in the further application of electronic skin and wearable electronics. Here, a flexible pressure sensor with rGO coated on a micro cone array was fabricated. By using the molecular dynamics simulation to investigating the formation mechanism of rGO, its optimized micro-morphology can be obtained and understood for improving the performances of sensors. Both an ultrahigh sensitivity (133.003 kPa−1, < 40 kPa) and a wide detection range (0–300 kPa, >10 kPa−1) were remarkably achieved due to the multiple embossments within interfaces of rGO. Furthermore, the designed sensor using rGO with embossments enables several practical applications, showing a fast response time (27 ms) in child door lock monitoring and a distinct step-shape response in robotic arm load monitoring, respectively. And no frequency dependence under loading is also observed obviously. In addition, micro-pressure monitoring, including heart beat (excellent robustness over 10,000 cycles) and vocal cord vibration (sound track), can be monitored clearly owing to embossments morphology of rGO as well. The simulation model of sub-microstructures on rGO shows that the embossments can build the multiple contacts within the interfaces for higher signals output. The designed sub-microstructures of rGO can be an effective strategy to afford superior performances of pressure sensors for universal applications in physiological signal monitoring and physical motion analysis.