Biologically Inspired Material Systems that have Hierarchically Structured Sensing, Actuation, and Intelligent Control

After engineers and scientists at Virginia Tech, Harvard and Drexel finish studying the locomotion of fish in water, Michael Phelps may find he still has a few new ways to increase his own world-breaking Olympic times.

The remarkable ability of fish to maneuver in tight places, or to hover in one area efficiently, or to accelerate in a seemingly effortless fashion has researchers wondering if they can create smarter materials that emulate the biology of these vertebrates.

With an eye towards homeland defense needs, engineers have also noted that fish through neuromasts or 'hairs' in the lateral line are able to sense very small changes in their watery environment that allows them to detect and track prey and to form hydrodynamic images of the environment.

Michael Philen, assistant professor of aerospace and ocean engineering (AOE) at Virginia Tech, has pulled together a team of researchers to study these abilities and hopefully develop biologically inspired material systems that have hierarchically structured sensing, actuation, and intelligent control. This research will lead to state-of-the-art advanced materials that can intelligently sense and actuate a network of distributed robust sensors and actuators.

Philen has prior experience in this area. As a post doctoral researcher at Penn State, he spent time on a three-year project with the Defense Army Research Projects Agency (DARPA) to develop a new structure/actuation system inspired by the mechanical, chemical, and electrical properties of plants.

Philen's proposal to the National Science Foundation's (NSF) Emerging Frontiers in Research and Innovation program to study fish to create smarter materials has received $1.95 million in funding. Philen's co-principal investigators are Harry Dorn, professor of chemistry, and Don Leo, associate dean of engineering, both at Virginia Tech. George Lauder, a professor of biology at Harvard, and James Tangorra, an assistant professor of mechanical engineering and mechanics at Drexel, round out the team.

Working together, the team will develop distributed sensors and actuators using nanotechnology, advanced composite technology, and smart polymeric materials for understanding the organization and structure of the control systems fish use for sensing and maneuvering.

With the inclusion of Harvard University, the research team also plans to develop a traveling exhibit on robotic fish that showcases the biology of aquatic propulsion, new actuator and sensing technologies and how these can be integrated to design a robotic fish. Harvard's Museum of Natural History (http://www.hmnh.harvard.edu/ with its links to "Kids and Families" and "Educators" receive some 33,000 school-aged visitors each year. They will have access to the robotic fish exhibit on line through this site.

Lisa McNair of Virginia Tech's Engineering Education Department, an expert on applying theories of interdisciplinary collaboration in research and teaching practices, will work with the Harvard Museum to assess the impact on the students' understanding of the biological mechanisms that allow fish to sense, swim and maneuver efficiently with minimal processing.

Philen explained that over the past 20 years experts such as George Lauder from Harvard have investigated a number of aspects of fish control systems for movement. These studies have shown that fish possess a two-gear muscular system that controls movement. One is for slow-speed movement and the other is for rapid movements and escape responses.

"Despite this progress, there is still very little understanding of the structure and organization of the hierarchical control systems in fish or how the actuation and sensing systems are integrated to perform steady and maneuvering locomotor tasks," Philen said. "Researchers have explored various system identification techniques for characterizing and understanding a number of biological systems, such as insect walking, renal autoregulation in rats, and locomotor oscillators in the spinal cords of lampreys. However, little or no research has been done on the hierarchal control systems found in fish."

The team of researchers plans to create a robotic fish-like underwater vehicle by integrating their biological investigations of the fish with engineering knowledge about sensors and actuators.

"We view this as an exciting opportunity to create a transformative leap in the development of new biologically inspired material systems," Philen said.