'Soft' robotic exoskeletons could guide physical rehabilitation

Researchers in France have developed soft, flexible robots that can help patients in physical rehabilitation regain mobility by mimicking human muscle.

The robots, controlled by changes in air pressure among a series of specially designed “soft balloons,” can be worn by patients performing rehabilitation exercises to help them stand upright and also guide their movements. The elastomer balloons are cucumber-shaped and inflate to become rigid and deflate to become less so. In this way they control the patient’s movements like a controllable exoskeleton.

Scientists from the École Polytechnique Fédérale de Lausanne are working with physical therapists from a nearby university to apply the exoskeleton to stroke victims. Wrapped around the patient’s torso like a large belt, the balloons restore motor sensitivity, lead researcher Matthew Robertson said in a statement.

Currently the system is controlled by a series of external pumps, and the team is looking to make it smaller so it can be accessed directly from the belt.

Exoskeletons like ReWalk Robotics’ have hit the market and have shown to be effective in niche areas, but they can cost a tidy sum. Though in the very early stages, the soft device could ultimately help make devices like this more suitable to the task and less expensive to manufacture. And because it’s not made of hard material, they have the potential to be physically safer.

“Our robot designs focus largely on safety,” said Jamie Paik, the director of EPFL’s Reconfigurable Robotics Lab. “There’s very little risk of getting hurt if you're wearing an exoskeleton made up of soft materials, for example.”

They published their results in the journals Soft Robotics and Scientific Reports.