Studies on the banked-turn of Coleopteran flight and electrical stimulation for wing oscillation and foreleg motion to elicit take-off and turning in flight

The flight behaviors of insects have been extensively studied for a long time. The idea of making use of natural insects to help human beings is attractive to a lot of researchers. With the continuing development of electronic devices and low-power wireless communication systems, many insect-body-mountable devices have been applied to measure the intrinsic insect behaviors, such as inertia measurement and extracellular recording. Some researchers even successfully applied extrinsic electrical stimulations on insects with tiny wireless stimulators. The appearance of these wireless devices inspired our research and extended our approach from tethered experiments to free flights. Specifically, my focuses are on the stimulated flight initiation of insects, the natural features of banked-turn in insect flight and the roles of foreleg motions in flight control. The result of flight initiation experiment demonstrated that it was reliable to initiate flight on beetle (Mecynorrhina torquata, Coleopteran) by electrically stimulating the dorsal longitudinal muscles (DLMs), indirect flight muscles that oscillate the wings. A high success rate with rapid response time on flight initiation was achieved by DLM stimulation. In the measurement of flight banked-turn, a MEMS inertia-measurement-unit was stuck on the pronotum of beetle. The results verified that the yaw angular velocity and body roll angle were highly correlated and the values of yaw angular velocity and roll angle followed a linear relationship. The analysis on foreleg motion revealed that the clockwise and counterclockwise swings of both forelegs were actively induced by beetle itself to deflect the flight course and balance the perturbation. Moreover, we believe that the effects of forelegs in flight should be attributed to their relatively large angular momentum.Doctor of Philosophy (MAE