Robotic exoskeletons, long a staple of sci-fi novels, comic books, and movies, are now part of the real world—and they’ve mostly followed the sci-fi model. That is, exoskeletons are wearable robots. All metal, all the time. But metal suits are heavy and power hungry, and the human body isn’t metal. If you actually plan to use an exoskeleton for an extended period of time, this can be a bit of a design flaw.
That’s where a new exosuit developed by SRI International is looking to flip the script. Instead of working to build exoskeletons—which are rigid like their namesake—SRI is using soft robotics to make lightweight, wearable “exomuscles” and “exotendons.”
Instead of a human-shaped heavy metal frame, SRI’s exosuit is soft, pliable, and intelligent. The suit learns and adapts to its wearer’s movements to give them a boost when needed. It’s quick to put on and relatively energy efficient.
SRI’s exosuit, called Superflex, was developed over the last few years with funding from Darpa’s Warrior Web program. Now, SRI is spinning off the invention into a new company (also called Superflex) to advance it further.
Rich Mahoney, former director of SRI’s robotics program, will head up the new venture. In 2014, he described the ethos behind Superflex as anti-exoskeleton, “It fits under your clothes, it’s quiet, it’s comfortable, it works very synergistically with your movements and just adds a little bit of energy at the right time during your gait to reduce the overall amount of energy that your body is using.”
Though the suit’s design has the look of something Batman might pick up from Special Projects at Wayne Enterprises, it isn’t really intended for the billionaire vigilante market. The team is focused on restoring everyday mobility for elderly and disabled folks.
“You know,” says Manish Kothari, head of SRI Ventures,”if you could get my 99-year-old grandfather to wear a piece of clothing that no one can see and it is actually helping him walk without a walker, that’s essentially Superman-type activity.”
Superflex uses a combination of sensors, electronics, and artificial “muscles” and “tendons” to track movement and give a quick burst of support to arms, legs, or torso at just the right time. This would allow an elderly person to move around without a cane or walker or steady their hand when grasping objects—reducing injuries without reducing freedom.
Power is, of course, a big challenge for any such invention. If it’s to be used every day, it needs to be powered for extended periods.
The suit weighs eight pounds, and three pounds of that goes to the battery. But it makes the most of the power it has. Unlike powered exoskeletons, Superflex isn’t always ‘on’. It only kicks into gear when needed, allowing the battery to last longer. Also, if it does run out of juice, it maintains full mobility, as opposed to freezing up like a rigid model might.
Add in the fact you can put it on in about five minutes—a number the team hopes to improve to two minutes—and you can see how the device could become practical. While there’s no word on cost yet, affordability is one of the project’s goals.
It’s a cool approach, but Superflex isn’t alone in the world of exosuits.
Another project, out of Harvard’s Wyss Institute and also part of the Warrior Web program, has its own suit. Headed up by Dr. Conor Walsh, the Harvard team is collaborating with exoskeleton company ReWalk to bring their suit to market.
Also, the advent of soft robotics exosuits doesn’t mean researchers shouldn’t also still pursue more traditional exoskeletons. Superflex would help people with partial mobility. But those without the use of their legs, for example, might still benefit from a true exoskeleton as a potential wheelchair replacement.
Work on exoskeletons, for both medical and industrial purposes, continues.
Ekso Bionics, Indego, and ReWalk make FDA-approved lower-body exoskeletons. And there are a few huge companies in the mix too. Hyundai and Panasonic are both working on exoskeletons aimed at industrial workers and the elderly.
We’ve written about powered exoskeletons for years, but as you may have noticed, they aren’t a particularly common sight out on the street yet.
Challenges like power, as noted above, and cost have kept them largely confined to the lab, small studies, and cool YouTube videos. And it may still be a while yet before we’re replacing wheelchairs, motorized scooters, and walkers with exosuits and exoskeletons.
But Kothari believes the field is passing an inflection point.
“From a venture point of view, one thing I noticed was that the costs have been brought down and the functionality has been brought up,” he says. “We’re really, in robotics, at that focal point where it’s more about usability, reliability, and maintainability. That’s really the right time to switch from an R&D type model to a commercialization model.”
Image credit: US Army RDECOM/FlickrCC
