Simon Sponberg, PhD (School of Physics & School of Biological Sciences, Georgia Institute of Technology)
Saad Bhamla, PhD (School of Chemical & Biomolecular Engineering, Georgia Institute of Technology)
Nick Gravish, PhD (School of Mechanical & Aerospace Engineering, University of California, San Diego)
David Hu, PhD (Woodruff School of Mechanical Engineering, Georgia Institute of Technology)
Kurt Wiesenfeld, PhD (School of Physics, Georgia Institute of Technology)
Beyond resonance in insect flight: strain-dependent actuation of deformable oscillatory structures
Insect flight is one example of a broad class of systems in which locomotion is powered via rhythmic movements. The dogma of the insect flight literature is that insects resolve the high power requirements of flight by operating at resonance. However, evidence suggests that a resonance model is incomplete. For instance, many species have evolved “asynchronous muscle,” in which contraction is controlled by mechanical stretch and decoupled from neural inputs. The central hypothesis of this proposal is that a critical missing piece in understanding insect flight dynamics is the strain-dependent properties of muscle, which introduces kinematics-forcing coupling. Mechanical testing experiments and analytical modeling of the insect flight apparatus show that resonance exists, but wingbeat frequencies are far above resonance. Furthermore, muscle physiology experiments find that traditional muscles exhibit some of the same properties that enable asynchrony, suggesting that physiological properties exist on a gradient. The remainder of this thesis will utilize simulation and robophysical experiments to explore the interactions between components of the insect flight system (nervous system, mechanics, and muscle) to develop a unifying framework of insect flight, and more generally, strain-dependent actuation of deformable systems. Finally, biological experiments will artificially induce asynchronous behavior in a synchronous flight muscle.