Hierarchical Synergetic Strategy for Iontronic Pressure Sensors with High Sensitivity and Broad Linearity Range

Flexible iontronic pressure sensors have attracted extensive attention in intelligent robots and wearable healthcare devices for their flexible properties and sensing functions. Introducing surface microstructures in iontronic pressure sensors has remarkably enhanced sensitivity, whereas achieving flexible pressure sensors with high sensitivity over a broad linear range remains challenging. Here, we propose a hierarchical synergetic strategy for flexible iontronic pressure sensors by combining hemisphere and porous microstructure, realizing high sensitivity (9.27 kPa-1), fast response speed (<15 ms), and linear pressure response (R2 = 0.998) over a broad range (10 Pa-400 kPa). The high linearity of the pressure sensor is attributed to the porous hemispherical microstructure, which improves compressibility and compensates for the effect of structural stiffening. The excellent application potential of our pressure sensors in healthcare monitoring and spatial pressure distribution is demonstrated. The porous hierarchical hemispherical microstructure provides a general strategy expected to be applied to other types of pressure sensors calling for both high sensitivity and high linearity.