High-Sensitivity and Wide-Range Biomimetic Crack Flexible Pressure Sensor

Flexible pressure sensors have gained significant attention due to their widespread applications in health monitoring, electronic skin, and human-machine interaction. To meet the diverse pressure detection needs of different body parts, flexible pressure sensors must exhibit high sensitivity, low detection limits, and a wide detection range. Inspired by the slit sensilla in spider legs, this study designed and fabricated a novel flexible pressure sensor by integrating a biomimetic metal crack-sensitive structure with a polyimide (PI) flexible substrate. By optimizing the crack-sensitive structure and substrate materials, we significantly enhanced the sensor's sensitivity and detection range. The sensor demonstrated an extremely high sensitivity (up to 56715 kPa(-1)), a wide measurement range (36 Pa-192 kPa), rapid response time (15 ms), low hysteresis (8%), excellent durability and repeatability (140 kPa, 1100 cycles). Experimental results indicate that the sensor could accurately monitor physiological signals such as pulse, respiration, and joint movements. Furthermore, the single biomimetic crack pressure sensor has been extended into a 3x3 sensor array, enabling spatial pressure mapping and recognition. This study not only theoretically demonstrates that optimized biomimetic crack designs and high-modulus materials can achieve high sensitivity and wide range in flexible pressure sensors, but also experimentally verifies the efficiency and practicality of the fabricated sensors in human health monitoring applications. Biomimetic crack flexible pressure sensor is expected to be widely used in physiological monitoring, human-machine interaction, and intelligent robotics in the future.