"Clicking" compliant mechanism for flapping-wing micro aerial vehicle

This paper presented a click mechanism, which is inspired by a Dipteran insect, for use in flapping-wing micro aerial vehicle. The clicking mechanism is integrated in a thorax-like compliant mechanism, which buckles and consequently produces a large wing stroke when driven by an electric motor. The thorax-like compliant mechanism can store elastic energy in flexible hinges and is good for storing kinetic energy expended during wing reversal. This work showed that clicking compliant mechanism produces more thrust per input power than a conventional non-clicking rigid-body mechanism. The clicking prototype weighs 3.58g, has 115° wing stroke, and is able to achieve hovering at 15.8Hz flapping frequency. The non-clicking prototype is lighter at 3.35g with a wingstroke of 100°, but could not achieve hover but could not achieve hovering even though driven by the same motor at a faster flapping frequency (16.2Hz) under the same driving voltage (4.9 V). The clicking prototype produces a thrust-to-power ratio of 2.17g/W, higher than 1.15g/W of the nonclicking counterpart.