Evaluation of the Thorax of Manduca Sexta for Flapping Wing Micro Air Vehicle Applications

Abstract

In the 1990's, DARPA awarded several contracts to companies to research, design, and construct a Flapping Wing Micro Air Vehicle (FWMAV). The tobacco hornworm hawkmoth ( Manduca sexta) provides an excellent model from which to gather knowledge pertaining to the development of a Flapping Wing Micro Air Vehicle (FWMAV). One of the major challenges in design of a FWMAV is the energy demanding nature of low Reynolds number flapping flight. Therefore, an understanding of the power required by the flight muscles to actuate the wings is essential for the design of a FWMAV. The M.sexta wing/thorax mechanism was evaluated as a mechanical system in order to gain insight to the mechanical power required to produce the full natural wing stroke. A unique dynamic load device was designed and constructed to mechanically actuate the upstroke and downstroke of the M.sexta in order to achieve the full flapping motion. Additionally, the forces applied through the flight muscles were directly measured in order to attain the power requirements of the flight muscles simultaneously. The experiment yielded wing stroke values of + 60 and – 35 degrees, which is what is seen in nature during hovering. The DVM and DLM muscle groups were calculated to have a power density of 112 W/kg with the vehicle energy density being 2.5 W/kg. The power output requirement indicates the need for a lightweight and energy-dense power source/actuator combination for the development of FWMAVs.