Highly sensitive pressure sensor with broad linearity via constructing a hollow structure in polyaniline/polydimethylsiloxane composite

Flexible pressure sensors are increasingly required for their widely practical applications in health monitoring, humanoid robotics and wearable electronics. Although the geometric microstructure design or active material selection for sensor has been manipulated by many researchers, achieving the desired pressure sensor possessing high sensitivity over a broad linear detection range is still challenging. Herein, a flexible and wearable pressure sensor is demonstrated based on the polyaniline/polydimethylsiloxane (PANI/PDMS) composite with hollow structure and micro-protrude surface structure. The sensitivity and linearity of the as-fabricated sensor could be greatly enhanced through the construction of hollow structure and micro-protrude surface structure, reaching a sensitivity of 0.641 kPa−1 over a broad linear range (0.05–60 kPa), and the sensor also exhibits stable cycling performances (6000 cycles), fast response time (200 ms) and recovery time (150 ms). Importantly, the sensing mechanism of this sensor is theoretically studied, a sensing model based on tunneling effect and contact mechanic is proposed and its validity is experimentally verified. Finally, the pressure sensor demonstrates practical applications in object operations, answering mouse click and feet movements, thereby providing a significant guidance for constructing advanced electronic devices.