Ultra‐Sensitive and Linear Flexible Pressure Sensors with Tri‐Scale Graded Microstructures for Advanced Health Monitoring and Robotic Perception
Rui Chen, Rui Chen, Qixian Zhang, Tao Luo, Rui Gao, Wei Zhou, Chunjin Wang
Abstract
Abstract Flexible piezoresistive sensors, which combine high sensitivity and a wide linear detection range, are ideal choices for human health monitoring and robotic perception. However, sensors often exhibit a trade‐off between sensitivity and linearity, with challenges caused by the incompressibility of soft materials and the stiffening of microstructures. In this study, a flexible pressure sensor with a 3D ordered tri‐scale graded microstructure, fabricated by laser processing, is proposed. The sensor achieves an ultra‐high sensitivity of 138.6 kPa −1 and a linear range up to 400 kPa ( R 2 = 0.99). The compensation behavior derived from the tri‐scale graded microstructure's compression deformation counteracts contact hardening and delays sensitivity saturation. Furthermore, the sensor demonstrates a minimum detectable limit as low as 3 Pa, with response and recovery times of 34/39 ms, showing excellent stability after over 24 000 repeated loading cycles. Physiological monitoring confirms that the sensor can accurately capture a wide range of pressure‐variations, including those from the carotid artery, jugular vein, respiration, throat vibrations, and foot pressure. Additionally, the sensor can be used for remote operation of robotic hands. This work provides a strategy for manufacturing flexible pressure sensors with a combination of high sensitivity, high linearity, and a wide pressure response range.