Hollow Microstructure-Based Iontronic Pressure Sensors with High Sensitivity and High Linearity over a Broad Range

Flexible pressure sensors play a key role in fields such as health monitoring, smart wearables, environmental sensing, and human-computer interaction. These applications require sensors capable of accurately detecting a wide range of signals across diverse scenarios. However, achieving both high sensitivity and good linearity across a wide pressure range remains a significant challenge, primarily due to the limited compressibility of conventional sensor materials and structures. Herein, we report iontronic pressure sensors based on hollow microstructures. The hollow microstructure effectively enhances the compressibility of the dielectric layer, yielding a high sensitivity (131.1-3364.1 kPa^-1) over a wide pressure range (2000 kPa). Moreover, by designing programmable gradient hollow microstructures, we simultaneously achieve high sensitivity (626.9 kPa^-1) and excellent linearity (R² = 0.998) over a wide pressure range (620 kPa). These resulting sensors exhibit ultrahigh pressure resolution (>0.004%) over the full pressure range. These sensors are capable of detecting a variety of signals, including pulse, swallowing, muscle movement, and bending, and can be applied to applications across varied pressure ranges. This demonstrates their substantial potential for applications in health monitoring and human-computer interaction. The proposed design strategy is generalizable and is expected to enhance the performance of sensors based on different sensing mechanisms.