Rice team’s extra limb powered by compressed air

The proof-of-concept ‘extra limb’ is one of several ideas the team has implemented with a textile-based energy harvesting system. The device was designed and built by Daniel Preston, an assistant professor of mechanical engineering, along with lead authors Rachel Shveda and Anoop Rajappan and their team.

Described in Science Advances, the prototype ‘arm’ is a piece of fabric that hugs the body when not in use, but extends outward when activated and incorporates an elastomer lining on the surface to maintain its grip on slippery objects. 

For demonstrations, Rice alumna Shveda would operate the arm with a switch. Preston said future versions could have sensors that anticipate the wearer’s intent and complete the movements.

In addition to the curling arm that can grip a cup or other small objects while one’s hands are full, the Rice lab built a shirt with a bellows-like actuator attached at the armpit that expands, enabling the wearer to pick up a ten pound object. Testing the apparel on a mannequin showed it could do so without an assist from human muscles.