High Sensitivity and Broad Range Flexible Pressure Sensor Using Multilayered Porous PDMS/AgNP Sponge

Flexible pressure sensors attract wide attentions in recent years for their significant applications in wearable electronics and health monitoring. It is strongly desired that a pressure sensor possesses both low detection limit and wide measuring capability, covering a broad pressure range from Pa to hundred kPa, to meet diverse demands in different applications. This paper proposes a novel flexible pressure sensor based on thermosensation, using a multilayered and graded-porosity polydimethylsiloxane/silver nanoparticle sponge as piezo-thermic transduction. The sensor exhibits a high sensitivity, a low detection limit of 4.1 Pa, and a wide measuring range up to 200 kPa, which leads to a high range-to-limit ratio of about 50 000. The pressure sensor is monolithically integrated with a temperature sensor and dissolves temperature-compensation. The unique combination of properties makes it feasible to monitor various human signals from subtle wrist pulse to finger tapping pressure and foot stepping pressure by a single device, which shows competent capabilities for multifarious applications in wearable electronics and health monitoring.