This Faculty Early Career Development (CAREER) project will help determine the scientific principles that help explain why birds fly more effectively than current, similarly-sized aerial robots. In fact, the extremely fast and efficient flight behaviors of birds enable them to outfly aerial robots in a wide range of performance metrics. Understanding how birds manipulate air flow and power their wings has vast societal application, ranging from improved aerial delivery robots in urban environments to more effective monitoring and surveillance for national security purposes. The PI's team will study several bird species in great depth and a larger number of species more generally, to better understand the biomechanistic trade-offs between specialist versus generalist flyers. This study will employ some of the world's most advanced engineering techniques to quantify and relate airflow, aerodynamic lift force, and body motion using instruments that make 1000 measurements per second. The research will help answer long-standing questions on how birds are able to generate lift with their wings, and integrate aerodynamics, behavior, and muscle physiology to advance our understanding of how flapping bird flight evolved. The scientific knowledge gained will aid engineers in the development of bird-inspired aerial robots. The teaching components will stimulate drone entrepreneurism in Silicon Valley. The outreach components will benefit underrepresented minority biology students at CSU Fresno, visitors of the California Academy of Sciences, K12 STEM teachers and their students.
This integrative and comparative study of how birds support weight with flapping wings, is the first to measure aerodynamic force in vivo for a total of more than 40 species. The research will provide a modern aerodynamic theory of bird flight that combines seven mechanisms to understand how bird flight performance evolved. The research team will first obtain combined aerodynamic force and muscle-strain measurements in vivo. These measurements will help clarify the unknown role of tendon in generating upstroke power and, ultimately, flight specialization. The team's field study of evolutionary biomechanics will represent the broadest in vivo sample of aerodynamic forces to date. Among other things, the team will outline the possible convergence of increased upstroke lift in hummingbirds and nectar bats compared to generalist flyers. The research will be enabled by state-of-the art, high-speed measurement and modeling techniques including motion capture, stereo and Tomographic Particle Image Velocimetry, novel aerodynamic force platforms, an advanced bird wind tunnel, muscle physiology techniques, and OpenSim musculoskeletal simulation software.
