Researchers with the École Polytechnique Fédérale de Lausanne in France are aiming to develop new medical aids for physical rehabilitation by using inexpensive, everyday materials to create soft robots that can behave like human muscles.
“Squishy, compliant, light and customizable” – these are not terms often come to mind when thinking of robots and robotics but they’re definitely applicable to the new breed of bots currently being produced from a range of materials like silicon, fabric, rubber and plastic.
Researchers at the École Polytechnique are now using soft robotics to come up with physical rehabilitation aids that not only mimic the way human muscles move but are designed with comfort and usability in mind.
“Our robot designs focus largely on safety,” says Jamie Paik, Director of the Reconfigurable Robotics Lab (RRL) at École Polytechnique and co-author of a new study published in the journal Nature-Scientific Reports.
“There’s very little risk of getting hurt if you’re wearing an exoskeleton made up of soft materials, for example.”
The RRL team created specially designed actuators (the mechanisms in a device or robot which control movement) called “soft balloons” which can flex and extend like muscles. Controlled by changes in air pressure, these cucumber-shaped actuators can stretch up to five or six times their length and bend in two directions. One prototype involves pink rubber tubes and fishing line put together into a therapeutic belt to be worn around the torso. The tubes can be formed into very precise shapes when inflated, conforming to a person’s body shape and, in the case of a stroke patient’s rehabilitation, the belt can help in rehab sessions aimed at restoring motor sensitivity.
“Using soft actuators, we can come up with robots of various shapes that can move around in diverse environments,” said Paik. “They are made of inexpensive materials, and so they could easily be produced on a large scale. This will open new doors in the field of robotics.”
An assistant professor at École Polytechnique, Paik completed her bachelor’s and masters degrees at the University of British Columbia in Vancouver and her PhD at Seoul National University in South Korea. Paik is a panel judge for the 2016 Soft Robotics Competitions, an annual event developed by the Harvard John A. Paulson School of Engineering and Applied Sciences at Harvard University.
Now in its second year, the competition is aimed at inspiring creativity and innovation in robotics and provides would-be competitors with an intellectual toolkit of ideas and designs to help get the creative and robotic juices flowing. The competition has posted information and video on last year’s winners.
The Harvard John A. Paulson School recently announced the invention of the “first autonomous, untethered, entirely soft robot,” nicknamed octobot for its inflatable arms. What’s special about octobot, the researchers say, is that it combines a pneumatic-based actuator and liquid fuel (hydrogen peroxide) with 3D printing technology to create an entirely “soft” machine.
“The struggle has always been in replacing rigid components like batteries and electronic controls with analogous soft systems and then putting it all together,” says Robert Wood, professor of engineering and applied sciences and lead researcher. “This research demonstrates that we can easily manufacture the key components of a simple, entirely soft robot, which lays the foundation for more complex designs.”
Below: Soft robots that mimic human muscles