Researchers at Vanderbilt University in Nashville, Tenn. and North Carolina State University in Raleigh, N.C., have developed an exoskeleton device that fits onto a person’s legs and mimics the work of human tendons. Unlike most exoskeleton devices, however, this one doesn't need a battery; it relies on a simple spring-and-ratchet mechanism.
Based on human physiology, the mechanism uses the elastic energy stored in the Achilles tendon of the standing leg, which is then released as that leg pushes into the ground to propel a person forward. A clutch engages as the Achilles tendon stretches and a spring—acting like a second tendon—stretches to store the energy that will be released as the person takes a step, according to a study published in the journal Nature.
Gregory Sawicki, a biomedical engineer and locomotion physiologist at NC State, said in a press release that this device could help stroke victims improve their walking ability. But he also added: “For a 65-year-old active person, it could really prolong their active years.”