Iron Man’s metallic suit might be capable of flight and come packed with innumerable futuristic gadgets, but it’ll also never happen. An ironclad, 225 pound exosuit isn’t remotely practical when you consider that the American man or woman weighs between 196 and 168 pounds, according to the CDC. A flying, grenade-launching suit isn’t all that helpful if you can’t lift your head.

That’s why two teams of researchers have been heard at work developing a customizable exosuit that weighs a fraction of the fictional outfit Tony Stark hauls around. The suit combines fabric components with battery-powered movers to form a system that weighs just under 20 pounds (9 kilograms). Compared with the Ironman suit its capabilities are a little less comic book — more about pushing the limits of human endurance as opposed to picking off desert-dwelling arms dealers with guided missiles — but still has the potential to be ground-breaking (it’s also real).

David Perry, a staff engineer at Harvard University and co-author of the study that developed this robotic suit, tells Inverse it can assist soldiers marching through rugged terrain, help firefighters carrying heavy loads, or even assist elderly people who have trouble walking because of disorders like Parkinson’s Disease, all while being minimally obtrusive.

“When you walk with the system it starts to fade into the background. You almost forget you’re wearing a robot,” he says about the exosuit that was presented at the 2018 IEEE International Conference on Robotics and Automation (ICRA) in May. “You’re reminded as soon as it’s turned off, though, and without the assistance you suddenly feel like you’re walking in sand.”

Essentially, the new suit helps you and your load feel lighter than it really is.

Making Exosuits a Reality

The suit straps textile material to the user’s waist, thighs, and calves. These components are attached to a battery inside of a backpack that powers the actuators that provide motor support to the aforementioned body parts. Perry and his team ran a field test in collaboration with the Army Research Labs that had soldiers suit up with the exosuit and walk through a 12-mile cross-country course, proving that their system was not just limited to lab settings.

This was then supplemented by a second study published in the Journal of NeuroEngineering and Rehabilitation (JNER), which optimized how much power the exosuit delivers at certain times. This upgrade measures how much force the wearer is exerting and how they move to provide custom assistance to each individual wearing the suit. The idea is to give you bursts of energy when you need them most.

“The personalization method proposed in this paper was intended to maximize the amount of assistance delivered to each wearer with respect to individual walking pattern, more specifically, maximizing mechanical power delivered to the wearer’s ankle joints during push off,” explains Sangjun Lee, first author of both the ICRA and JNER studies and Harvard Ph.D. Candidate.

The study found this method reduced the metabolic cost — or amount of calories burned — of walking by roughly 15 percent compared to walking without the exosuit on. According to The American Council of Exercise, a 120-pound person burns about 11.4 calories per minute, so if they ran a 10-minute mile they’d burn 114 calories. If they’d do the same with the exosuit that would be cut down to 97 calories. This doesn’t seem like a big difference, but the design is where Perry and Lee’s work shines.

Exosuits are pushing the limits of human endurance.

Who’s Using Exosuits

Currently, the most widely used exosuits have been implemented in factories to assist workers with long and laborious shifts, an example is the EksoVest used at Ford factories. These are rigid and are mostly used for overhead tasks to help workers keep their arms up without straining their shoulders or backs. But this is obviously a pretty major limitation as far as what you can do when you’re wearing it. The ICRA and JNER studies, by contrast, provides a suit that’s nimble enough for first responders to easily wear along with their usual uniforms.

Currently, ReWalk — a robotics company focused on rehabilitation — is taking a medical version of the exosuit through clinical trials. In the future Perry hopes to partner with military-focused companies to provide them with this tech on the field.

“This is definitely an exciting and plausible future. The system highlighted in our paper is designed to make walking easier, so imagine rescue workers and firefighters getting assistance while they carry heavy loads up stairs and out to people who need help,” he says. “There’s still a lot to learn and improve, but ReWalk is taking the first commercialization steps now with our medical system, and additional applications aren’t too far behind.”

If exosuits like this are even able to reduce your calorie consumption by a quarter, we could see a future where professionals that have intense, physically demanding jobs are required to wear them. Firefighters could be the next Iron Men.