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Virginia Tech News / Articles / 2005 / 03 

Engineering students design robotic arm for competition

March 3, 2005

On March 7, three Virginia Tech engineering science and mechanics seniors will travel to San Diego with a robotic arm they designed and built to compete in an arm wrestling challenge against a human.

The robotic arm will face a straight A high school senior, Panna Felsen, who was selected by the Society of Photo-Optical Instrumentation Engineers (SPIE). The San Diego high school student also will use her physical strength against two other artificial arms, one of which was developed by the Swiss Federal Laboratories for Materials Testing and Research, and the second by Environmental Robots Inc. of Albuquerque, N.M.

Felsen founded an engineering club at her school for which her robotics knowledge helped the team win KISS Institute's National Research and Design Challenge. She also led the design team that built and programmed autonomous robots that earned second place at Southern California Regionals.

Felsen's Virginia Tech design opponents are: Steven Deso of West Chazy, N.Y., Noah Papas of Greensburg, Pa., and Stephen Ros of Paramus, N.J. They are advised by John Cotton, assistant professor of ESM, specializing in biomedical engineering and who is a member of the Virginia Tech-Wake Forest School of Bioengineering and Sciences.

Their robotic arm uses electro-active polymers (EAPs) as the artificial muscle. EAPs are a relatively new breed of polymer that responds to external electrical stimulation by displaying a significant shape or size displacement. Researchers in the biomimetics arena believe these materials may be able to mimic the movements of human body parts.

A leading researcher on EAPs, Yoseph Bar-Cohen, a physicist at the Jet Propulsion Laboratory (JPL). proposed the competition. Business Week named Bar-Cohen in April 2003 as one of five technology gurus who are "Pushing Tech's Boundaries" for his contributions to the field of EAPs.

The students' design cost them less than $1,000. They also were able to secure donations from companies including Biomet, a manufacturer of joint implants and related orthopedic products, and Mitibishi-Rayonco, a producer of plastic optical fibers and hollow fiber membranes.

The robotic arm has a composite skeleton, artificial muscle, and an integrated control system. The students used a specific type of fiber, polyacrylonitrile gel. It reacts to changes in pH, allowing it to contract like a muscle and return to normal shape. It is designed specifically to meet the needs of the motions and force associated with the sport of arm wrestling.