Bioinspired flexible piezoresistive sensor with cross-gradient architecture for high-performance tactile sensing

Tactile perception, as a core technology for flexible sensing, holds significant promise for advanced applications in biomedicine and human-computer interaction. However, achieving the simultaneous optimization of high-performance signal sensing (wide detection range and high sensitivity) and response stability remains a critical challenge for advancing tactile sensors in various applications. Here, inspired by the structural arrangement of snake scales, an innovative flexible tactile sensor with a cross-tilted gradient (CTG) architecture is constructed. The sensor achieves high sensitivity of 2.116 kPa^-1 and a wide detection range of 511.11 kPa through the synergistic effect of an ultra-dense sensing point design and a multi-gradient structural compensation mechanism. Additionally, through interfacial compatibility design and plasma surface treatment, we prepare MXene/PET electrodes with high friction resistance, high conductivity, and strong interface adhesion at room temperature using a flexible electronics direct-write system. The bioinspired sensor exhibits outstanding response characteristics (response time of 8 ms), long-term operational stability (>8500 cycles), and no significant signal drift. Its outstanding sensitivity enables comprehensive human posture sensing. Furthermore, by expanding and integrating individual sensors, high-precision perception of multi-tactile information and effective human-machine interaction are achieved.