posted on 2019-03-14, 00:00authored bySungwoo Chun, Wonkyeong Son, Changsoon Choi, Hyeongho Min, Jiwon Kim, Heon Joon Lee, Dongjin Kim, Changhwan Kim, Je-sung Koh, Changhyun Pang
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.