Highly sensitive flexible pressure sensor based on ionic dielectric layer with hierarchical ridge microstructure

Although the flexible pressure sensors have been widely applied in many applications, such as human-machine interaction and electronic skins owing to their excellent mechanical robustness and fast response time, the fabrication is still not highly scalable and low-cost. Also, the sensitivity in low pressure range is not satisfactory. This paper presents a flexible pressure sensor based on the ion gel film with hierarchical ridge microstructure fabricated by a simple, scalable and low-cost way. The ionic sensor has a high sensitivity of 145.45 kPa−1 in the low-pressure range (<400 Pa). Besides, the ionic sensor exhibits good linearity in the low-pressure range and shows a fast dynamic response time of ∼44 ms, a low detection limit of 0.4 Pa, and mechanical stability for over 6200 cycles. The practical applications were demonstrated with this sensor, including the detection of human pulse, breathing and tiny magnetic force. Finally, A sensor array of 7 × 7 pixels was also developed to map the pressure distribution. This work provides a promising way to fabricate a flexible pressure sensor with high performances in a scalable and low-cost way.