Bioinspired Hairy Skin Electronics for Detecting the Direction and Incident Angle of Airflow

TLDR

Human skin’s hair-like structures inspire multimodal sensing, with high‑aspect‑ratio hairs detecting subtle airflow or touch displacements. The study introduces hairy skin electronics comprising a 16‑pixel graphene sensor array and artificial microhairs to capture tactile stimuli and detailed airflow characteristics. The graphene nanoplatelet percolation network simultaneously measures pressure, temperature, and vibration with an ultrahigh response time of <0.5 ms (2 kHz). The microhair‑covered device maps electrical signals from noncontact airflow, accurately determining wind direction, incident angle, and intensity, and when mounted on a sailing robot, it alters locomotion and speed accordingly.

Abstract

The human skin has inspired multimodal detection using smart devices or systems in fields including biomedical engineering, robotics, and artificial intelligence. Hairs of a high aspect ratio (AR) connected to follicles, in particular, detect subtle structural displacements by airflow or ultralight touch above the skin. Here, hairy skin electronics assembled with an array of graphene sensors (16 pixels) and artificial microhairs for multimodal detection of tactile stimuli and details of airflows (e.g., intensity, direction, and incident angle) are presented. Composed of percolation networks of graphene nanoplatelet sheets, the sensor array can simultaneously detect pressure, temperature, and vibration, all of which correspond to the sensing range of human tactile perceptions with ultrahigh response time (<0.5 ms, 2 kHz) for restoration. The device covered with microhairs (50 μm diameter and 300 μm height, AR = 6, hexagonal layout, and ∼4400/cm2) exhibits mapping of electrical signals induced by noncontact airflow and identifying the direction, incident angle, and intensity of wind to the sensor. For potential applications, we implement the hairy electronics to a sailing robot and demonstrate changes in locomotion and speed by detecting the direction and intensity of airflow.