Scientists design soft robotic exoskeleton to reduce fatigue

[rhoenix]

The term “robotic exoskeleton” conjures up images of a heavy contraption with a metal frame and powerful motors that endow the wearer with super-human strength. While that’s certainly one way to think of robotic exoskeletons — like some members of Daewoo’s workforce slip into on a daily basis — scientists at Harvard have developed a new type of flexible fabric exoskeleton that could prove far more practical. It’s interesting enough that Harvard’s Wyss Institute for Biologically Inspired Engineering has been granted $2.9 million by DARPA to continue development of the technology.

Unlike the traditional exoskeleton concept, Harvard’s so-called “Soft Exosuit” is not designed to give the wearer vastly increase lifting capacity. Instead, the Soft Exosuit works with the musculature to reduce injuries, improve stamina, and enhance balance even for those with weakened muscles. In some ways, this approach to wearable robotics is the opposite of past exoskeletons. Rather than the human working within the abilities and constraints of the exoskeleton, the exoskeleton works with the natural movements of the human wearer.

It was actually harder than you might expect to design a wearable machine that didn’t get in the way. The Soft Exosuit is attached with a network of fabric straps, but that’s only the beginning. Researchers had to carefully study the way people walk and determine which muscles would benefit from the added forces offered by the Soft Exosuit. With a better understanding of the biomechanics involved, the team decided to go with a network of cables to transmit forces to the joints. Batteries and motors are mounted at the waist to avoid having any rigid components interfering with natural joint movement.

The wearer doesn’t have to manually control how the forces are applied, or stick to a certain pace when walking with the Soft Exosuit activated. The machine is supposed to work with the wearer, not the other way around, remember? The designers integrated a network of strain sensors throughout the straps that transmit data back to the on-board microcomputer to interpret and apply supportive force with the cables.

DARPA is funding this project as part of the Warrior Web program, which seeks to reduce musculoskeletal injuries for military personnel. However, Harvard also expects this technology to be useful in civilian applications. Anyone who needs to walk for long periods of time at work could benefit from the Soft Exosuit. It’s less expensive and considerably more comfortable than metal exoskeletons as well. It could even be worn under clothing if the batteries and motors can be scaled down or repositioned a bit.

The Soft Exosuit may end up having the biggest impact in the treatment of those with physical impairment. Someone that has trouble standing or walking could possibly attain normal mobility with the aid of this wearable robot. The team plans to collaborate with clinical partners to create a version of the exosuit for this purpose. What we’ve seen so far is just the general proof-of-concept for the Soft Exosuit. Luckily, it can easily be modified at the team tests each use case because it’s fabric instead of metal.

I think this is a great advancement of this concept, and one that will hopefully help people with ambulatory disabilities, as well as construction, medicine, and of course, the military.