Optical Measurement of the Deformation, Motion, and Generated Force of the Wings of a Moth, Mythimna Separata (Walker)

Motion and deformation of the wings of a moth Mythimna Separata (Walker) tethered to a steel beam were measured by using an optical method that uses fringe pattern projection. Simultaneously, the vertical force due to aerodynamic force generated by the wings was estimated by measuring the bending deformation of the beam during flapping motion of the moth. The force was estimated by subtracting the vertical forces due to inertial and centrifugal forces acting on the wings, which were estimated from the measured flapping motion, from the measured vertical force. Both the measured motion and deformation of the wing and the estimated vertical aerodynamic force generated by the wings suggest that the feathering angles are mainly affected by the inertial moment generated by the flapping motion and that the wing camber is mainly affected by the aerodynamic force generated by the wing.