A Tangentially Sensitive Tactile Sensor Reveals the Stick-Slip Mechanism and Enhances Robotic Tactile Sensing

The mechanism of human tactile perception offers inspiration for developing a high-performance artificial sensory system. Pacinian corpuscles (PCs) allowing high-frequency tangential sensitivity that endows humans with the ability to perceive multidimensional tactile stimuli. However, replicating similar high-frequency and tangential perception as that of PCs in artificial systems remains a significant challenge. Here, an artificial PC (APC) from ultralight aerogel with a multilayer-stacked and anisotropic structure analogous to that of PC via a multi-directional freeze-drying method is reported. The APC sensor with radial-axial anisotropy exhibits tangential sensitivity (1022 kPa^-1), detects multidimensional tactile stimuli, and identifies stick-slip states with high precision. By mimicking PC clusters, the APC sensor system achieves spatiotemporal sensing capabilities for discriminating frictional patterns (static, sliding, or rolling) and tracking slip. A robot equipped with the APC sensory system possesses enhanced tactile perception for diverse tactile events in active (100% accuracy) and passive (98.18% accuracy) interaction with humans. It is found that high-frequency components are crucial for stick-slip detection, providing insights into the underlying tangential tactile sensing mechanisms of PCs. The work exemplifies a bidirectional enhancement of understanding between technological innovation and biological mechanisms.