Iontronic pressure sensor with high sensitivity over ultra-broad linear range enabled by laser-induced gradient micro-pyramids

Despite the extensive developments of flexible capacitive pressure sensors, it is still elusive to simultaneously achieve excellent linearity over a broad pressure range, high sensitivity, and ultrahigh pressure resolution under large pressure preloads. Here, we present a programmable fabrication method for microstructures to integrate an ultrathin ionic layer. The resulting optimized sensor exhibits a sensitivity of 33.7 kPa(-1) over a linear range of 1700 kPa, a detection limit of 0.36 Pa, and a pressure resolution of 0.00725% under the pressure of 2000 kPa. Taken together with rapid response/recovery and excellent repeatability, the sensor is applied to subtle pulse detection, interactive robotic hand, and ultrahigh-resolution smart weight scale/chair. The proposed fabrication approaches and design toolkit from this work can also be leveraged to easily tune the pressure sensor performance for varying target applications and open up opportunities to create other iontronic sensors. Developing iontronic pressure sensors with high sensitivity in a wide linear range can be challenging due to a trade-off between sensitivity and linear range. Here, authors bypass this limitation by using laser-assisted gradient micro-pyramids and insights from multiphysics simulations.

Automated summary

In this study, a programmable fabrication method was proposed to integrate an ultrathin ionic layer into a pressure sensor, achieving excellent linearity, high sensitivity, and ultrahigh pressure resolution under large pressure preloads. The optimized sensor exhibited a sensitivity of 33.7 kPa(-1) over a linear range of 1700 kPa, a detection limit of 0.36 Pa, and a pressure resolution of 0.00725% under 2000 kPa pressure. The sensor showed rapid response/recovery and excellent repeatability, and it was applied to subtle pulse detection, interactive robotic hand, and ultrahigh-resolution smart weight scale/chair.