Exosuits have featured prominently in comic books and films for decades, but as they move from research labs to the work environment, they're looking more like couture from Robin Hood: Men in Tights than artifacts from Iron Man.
Exosuits, or exoskeletons, that assist human activity date back to the late 19th century, but weren't practical initially. At least in the US, powered exosuits became a serious research goal in the 1960s, when General Electric and the US military began working on the Hardiman [PDF]. The project proved unsuccessful, but recent research looks more promising.
In the past decade, the notion of powered body armor has given way to more focused forms of muscular assistance. In part, this is due to the challenge of powering a heavy, worn machine for long periods. It's also a function of the fact that there are both military and medical applications of exosuits where freedom of movement and lack of weight matter more than potential for physical protection on a battlefield.
What's more, lightweight exosuits, which can be concealed with outerwear, don't call attention to themselves the way that an Iron Man battle suit would. Social acceptability may not matter in conflict scenarios, but as the cautionary tale of Google Glass demonstrates, it does need to be considered for civilian applications.
DARPA's Warrior Web project, for example, aims to produce "a lightweight, conformal under-suit that is transparent to the user (like a diver's wetsuit)."
Researchers with the Harvard Biodesign Lab (which has been involved with projects like DARPA Warrior Web), working with collaborators from Harvard's Wyss Institute for Biologically Inspired Engineering and other academic and medical institutions, are well on the way toward making exosuits practical products.
In a research paper [PDF] published earlier this month, a group of exosuit scientists report that their ~2 pound (0.89 kg) soft exosuit consisting of a spandex base layer, a waist belt, two calf wraps, four vertical straps, and an actuator can reduce the metabolic rate of walking by about 23 per cent when powered on.
Assistance to that extent may only partially compensate for medical conditions like stroke, Parkinson's disease, and cerebral palsy, which can increase the net energy expenditure of walking by as much as 70 per cent, according to the paper.
The researchers acknowledge that further work needs to be done to refine the technology.
The paper notes that while various approaches to assisted walking have been developed over the past decade, designs with rigid frames have tended to increase the wearer's energy expenditure because they restrict natural gait dynamics. Soft exosuits don't disrupt natural biomechanics in the same way.
The researchers foresee their exosuits helping soldiers carry heavy loads, helping patients with muscular weakness (age or condition related), and even enhancing recreational activities and sports. ®