Researchers develop ‘extra limb’ fueled by air

An ‘extra limb’, powered by compressed air derived from walking, with the capability of grasping objects has been built by mechanical engineers at Rice University in the US.
The prototype ‘limb’ is one of many ideas the team has executed with a textile-based energy harvesting system. The device was built and designed by Daniel Preston, an assistant mechanical engineering professor and lead authors Anoop Rajappan and Rachel Shveda and their team.
The proof-of-concept ‘extra arm’ is a piece of fabric that stretches outward when triggered and utilises a lining on the surface to maintain a grip on slippery objects, and when it is not in use, it hugs the body.
Shveda, Rice alumna, would operate the arm with a switch for demonstrations. It was said that upcoming versions could have sensors that complete movements after anticipating the wearer’s intent.
In addition to the curling arm, able to grip small objects when hands are full, a shirt with a bellows actuator attached at the armpit that expands was built by the Rice lab that enables the wearer to pick up a ten-pound object. It can do this without assistance from human muscles, as demonstrated by a test on a mannequin.
A postdoctorate supported by the Rice Academy of Fellows, Anoop Rajappan, “Census statistics say there are about twenty-five million adults in the United States who find it difficult to lift ten pounds with their arms. That’s something we commonly do in our daily lives, picking up household objects or even a baby.”
The apparatus requires two components: pneumatic actuators and textile pumps embedded in the soles of walking shoes that harvest air pressure. The pumps are full of open-cell polyurethane foam, allowing them to revert to their original shape after every step.