Tunable ionic pressure sensor based on 3D printed ordered hierarchical mesh structure

Flexible pressure sensors play an indispensable role in numerous future technologies for human beings, especially those with high sensitivity, broad sensing range and tunable fabrication methods. Herein, we demonstrate a tunable ionic pressure sensor based on the dielectric layer with ordered hierarchical mesh structure ( OHMS). The OHMS layer was fabricated by a simple and adaptable 3D printing technique, therefore the performance of the sensor can be tuned. Owing to the OHMS and electrical double layers (EDL), the sensor exhibits a high sensitivity of 72.86 kPa(-1) in the ultralow pressure range (<0.4 kPa), a fast response time within 43 ms, a high stability for over 7300 cycles, and a broad pressure sensing range from 1 Pa to 400 kPa. The sensor is demonstrated with practical applications, including Morse code, solvent evaporation detection, breathing, swallowing, wrist pulse, and plantar pressure measurement. This work may provide a new approach to tailor and improve the performance of ionic pressure sensors, which have great potential for innovative applications in wearable health-monitoring devices and human-machine interface systems. (C) 2020 Elsevier B.V. All rights reserved.