A 2.86 gram robotic insect with flapping frequencies up to 65Hz was developed to investigate the aerodynamic performance of high frequency flapping wings. The mean lift force was measured by an lever platform with a precision of 0.2mN. Experimental results showed that the lift increased with the flapping frequency in a quadratic manner and was saturated when frequency was beyond 35Hz. A 35 mN lift as well as the highest efficiency was achieved when the robotic insect flapped at 35 Hz. In order to explain the lift saturation, the flow patterns of MAV were investigated by using a DPIV system. Two major issues were found: first, the Leading Edge Vortex (LEV) loses stability and partly sheds away when the frequency is higher than 35Hz; second, the induced flow generated by left and right wings diverge to left and right sides, respectively, which is probably due to the strong tip vortices that were shed into the downwash.
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