Highly Sensitive Pressure Sensor Based on Bioinspired Porous Structure for Real-Time Tactile Sensing

A flexible pressure sensor with high performances is one of the promising candidates for achieving electronic skins (E-skin) related to various applications such as wearable devices, health monitoring systems, and artificial robot arms. The sensitive response for external mechanical stimulation is fundamentally required to develop the E-skin which imitates the function of human skin. The performance of capacitive pressure sensors can be improved using morphologies and structures occurring in nature. In this work, highly sensitive capacitive pressure sensors based on a porous structure of polydimethylsiloxane (PDMS) thin film, inspired on the natural multilayered porous structures seen in mushrooms, diatoms, and spongia offilinalis, have been developed and evaluated. A bioinspired porous dielectric layer is used, resulting in high-performance pressure sensors with high sensitivity (0.63 kPa⁻¹), high stability over 10 000 cycles, fast response and relaxation times, and extremely low-pressure detection of 2.42 Pa. Additionally, the resulting pressure sensors are demonstrated to fabricate multipixel arrays, thus achieving successful real-time tactile sensing of various touch shapes. The developed high-performance flexible pressure sensors may open new opportunities for innovative applications in advanced human-machine interface systems, robotic sensory systems, and various wearable health monitoring devices.