This Collaborative research project will study the biomechanics of Monarch butterfly flight, with the goal of creating engineered flight vehicles with unprecedented capabilities. The seemingly fragile Monarch exhibits the longest flight range among insects. Individual Monarch butterflies may travel up to four thousand kilometers during the annual migration between North America and Central America. This project will examine the distinguishing characteristics of Monarch butterfly flight, including the slow tempo of the flapping wings, the effects of wing flexibility, and the mechanical coupling of wing and body movements. Furthermore, the Monarch flies at relatively high altitudes. Glider pilots have observed Monarch butterflies soaring on thermal currents at altitudes up to 1,250 km, and their overwintering grounds are at altitudes of up to 3,300 km. This project will examine whether the unmatched range of the Monarch among similarly sized animals lies in the combination of large, flexible wings, slow flapping speeds, and high-altitude flight. A multidisciplinary team will integrate expertise in computational mechanics, biological experiments, fluid dynamics, and nonlinear controls to uncover the physical mechanism underlying the highly efficient Monarch flight. This knowledge will be applied to the creation of transformative, bio-inspired micro-air vehicles with enhanced flight efficiency and superior flight range. Micro-air vehicles with extended flight range will improve the national quality of life by enabling long-term monitoring of environmental hazards. These vehicles will enhance national security by allowing long-term surveillance of large areas, and by providing long-range reconnoitering capacity for search and rescue. Engineering models of Monarch flight will also contribute to the understanding of their migration patterns, and thereby support the conservation of this endangered species.
The primary scientific objective of this project is to test the hypothesis that high-altitude flight is a critical component to the long-range flight characteristics of the Monarch butterfly. This will be achieved with a series of experimental, computational, and theoretical research efforts. The flight maneuvers of live Monarch will be measured by a motion capture system in a low-pressure chamber simulating the ambient environment at various altitudes. The measurements will be validated with computational fluid dynamics simulations for the unsteady viscous flows around flexible flapping wings integrated with a multibody dynamics model representing the thorax and the abdomen deformation. The resulting aerodynamic model will be approximated by an artificial neural network for real-time dynamic simulation, from which a nonlinear feedback control system will be constructed via Floquet-Lypuanov theory. The fidelity of the computational dynamic model and the feedback control system will be verified against experiments with Monarch butterfly inspired micro-air vehicle and live butterfly flight measurements. These will provide a comprehensive analysis of the low-frequency flapping dynamics of an articulated, flexible multibody system representing the remarkable flight characteristics of Monarch butterflies.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
