Robust and Sensitive Sensing of Unsteady Flows Using a Hair-Like Macroscopic Graphene Fiber

This paper reports a bio-inspired miniaturized hair-cell flow sensor using a novel material—graphene fiber (GF). We demonstrate that GF can be bent into an arc-shape and stick out of air flow boundary layer for velocity measurement. Air flow velocities ranging from 0.6 to 3.2m/s are generated to characterize the measurement sensitivity. It is found that flow velocity as low as 0.06m/s can be detected by the GF-based hair-cell sensor. Moreover, to measure the dynamic response of the GF-sensor, a periodic unsteady flow is generated by a single blade fan. The dominant frequency, i.e. the fan rotating frequency, has been clearly captured by the GF-based hair-cell sensor. This GF-based hair-cell sensor shows great promise in detecting small air flow and can be implemented in an array form on wings of small/micro flying vehicles for providing crucial aerodynamic flow field information on wings.