A Three-Dimensional Micro- and Porous Structure with Multiscale Deformation Synergy for Soft Pressure Sensing

Abstract

Recent advances in soft pressure sensors have explored various structural designs to improve sensitivity and mechanical compliance. Among various three-dimensional (3D) structures based on soft elastomers, porous structures have been widely employed to achieve large compressibility and flexibility. However, conventional porous structures suffer from low initial sensitivity due to their limited deformation in the linear elastic regime. In this study, we propose a soft pressure sensor that combines a 3D surface microstructured layer and a porous elastomer matrix to exploit their multiscale deformation behavior. The simultaneous compression of the surface microstructures and the linear elastic deformation of the porous matrix under small pressures significantly enhance the sensor sensitivity, achieving a value of 0.177 kPa–1 in the low-pressure range. The proposed sensor exhibits excellent sensing performance under both static and dynamic loading conditions, demonstrating high repeatability, low hysteresis (7.47%), fast response time (255 ms), and reliable operation, thereby overcoming the limitations of conventional porous-based sensors. Furthermore, the sensor demonstrates practical applicability in wearable sensing, enabling reliable monitoring of diverse human motions. Finally, Bluetooth-based pressure sensor arrays were integrated into a smart glove for grasping tasks and a shoe insole for monitoring squat motions.