Scientists at the Georgia Institute of Technology, Atlanta; the University of Alabama, Tuscaloosa; and Vanderbilt University, Nashville, TN, announced a four-year joint project to develop a below-knee prosthesis capable of actively powering the ankle joint powered by a gas- or liquid-based propellant.
Electric prostheses have several significant limitations. Since batteries have a limited energy density, those using a prosthesis with an electric motor must recharge the unit on a regular basis. By using a propellant, an individual may get several days’ worth of power from one fuel canister.
There are two key components in the new prosthesis. One is a special type of liquid fuel called monopropellant, which works as an energy-storing medium and decomposes upon contact with certain catalysts.
The second is a sleeve muscle actuator, an artificial muscle that replaces the motor used in some alternative prosthesis as the prosthetic actuator. The sleeve muscle is more powerful, lighter weight, with a more compact profile, and its elastic properties are similar to a biological skeletal muscle.
After the research element of the project is completed, the Alabama researchers will test the device at Georgia Tech using a multi-camera motion capturing system to measure the user’s gait.
