The robotic platform for the colony of artificial bees will be designed using principles derived from insect biomechanics and the fluid dynamics of flapping wings. Proper design of all mechanical and aeromechanical components of the robotic bee are crucial, since propulsive efficiency will determine flight time, and payload limitations will determine the size and mass available for sensing, communication, and other on-board electronics.
Similarly, actuator power requirements necessitate the development of efficient drive electronics, and require portable power sources with high energy-to-weight ratios. Therefore, a rigorous study of the coupled mechanics and aerodynamics of an insect-scale vehicle is essential to the success of this project.
Realization of the body will require extensive research in (1) aerodynamics and control of flapping-wing flight, (2) design and fabrication of the flight apparatus, and (3) portable power sources and drive electronics.
For More Details on Specific Topics See Below:
RoBeep: Power Sources for Miniature Autonomous Systems
Team: Shriram Ramanathan (faculty), Kian Kerman, Suhare Adam (Grad Students), Siya Xuza (Undergrad student), Quentin van Overmeere and Yuto Takagi (Visiting Scholars)
Miniature thin film solid oxide fuel cells that can be embedded in silicon and kapton platforms have been developed. A substantial effort on materials research and design is involved in this study, that includes the following aspects: 1) oxide electrolyte and electrode materials synthesis in thin film form and suspended membrane form for high performance fuel cell devices, 2) fundamental understanding of ionic and electronic transport in confined structures under extreme chemical potential gradient, 3) detailed analysis of fuel cell performance and limiting factors and 4) fabrication of integrated fuel cells into robotic skins which requires a deep understanding of microstructural effects in thermo-mechanical stability. Key results to date include the first demonstration of scalable thin film solid oxide fuel cells, demonstration of energy storage in fuel cells by design of multi-functional oxide anodes, high performance operation in a variety of fuels including hydrogen, methane and natural gas. The project has also allowed education and research training of a diverse group of undergraduate and graduate students. Strong collaborations exist with other PIs in the project, including Professors Mahadevan and Wood.
Figure caption: Chip-scale solid oxide fuel cell arrays
Figure caption: Use of
vanadium oxide anode allows energy storage in quasi-2D oxide fuel cell
Title: Flexible insect wings and flight stability in turbulent airflow
We are investigating several aspects of insect structure and flight control that play key roles in the exceptional flight performance of living insects, with direct relevance to the design of efficient, stable Robobees. Our current projects focus on two areas that remain poorly understood in the biological and engineering literature: the effects of wing flexibility on aerodynamic force production and the influence of turbulent, unsteady airflow on flapping flight stability. We have recently provided the first definitive, experimental evidence that insect wing flexibility improves aerodynamic force production. By experimentally stiffening a flexible vein-joint in bumblebee wings, we showed that passive bending, particularly as the wings stop and reverse direction at the end of each half-stroke, significantly improves aerodynamic force production. We have also shown that several different wing design strategies (including flexible zones that yield under excessive force) can reduce the damage that accumulates in insect wings due to collisions with obstacles. Finally, we are exploring the effects of complex, environmental airflow on insect flight stability through wind tunnel tests of stability and control in unsteady, structured wakes, and outdoor tracking experiments that explore how insects alter their movement patterns in response to windy, turbulent conditions.