Origami-inspired soft robots lift 1000x their own weight for a dollar
Harvard, MIT researchers’ vacuum powered actuators can be built in 10 minutes but possess superhero-level strength to weight ratio.
“Artificial muscle-like actuators are one of the most important grand challenges in all of engineering,” said Rob Wood, Ph.D., one of the research team leads and a Founding Core Faculty member of the Wyss Institute. “Now that we have created actuators with properties similar to natural muscle, we can imagine building almost any robot for almost any task.”
The actuators are composed of a metal coil or a folded plastic sheet surrounded by air or fluid and a plastic or textile skin. Sucking the fluid out with a vacuum pump causes the actuator to collapse in pre-determined ways defined by the coil’s shape or the folds in the robotic arm’s plastic, origami-like “bones.” Capable of shrinking to 10% their original size, the actuators are soft enough to lift delicate objects but can generate about six times more force per unit area than mammalian skeletal muscle. For example, a 2.6-gram muscle can lift a 3-kilogram object, approximately the equivalent of a duck lifting a car.
“One of the key aspects of these muscles is that they’re programmable, in the sense that designing how the skeleton folds defines how the whole structure moves,” says research lead Shuguang Li, Ph.D., a postdoctoral fellow at the Wyss Institute and MIT CSAIL. “You essentially get that motion for free, without the need for a control system.”
For perspective, soft robots lack the rigidity and precise accuracy of traditional “hard” robotics, while also being as susceptible to system leaks as fluid power actuators but without their speed and tolerance for high internal pressures. However, the researchers say their soft actuators are intended for novel robotic applications ranging from miniature surgical devices to large deployable structures for space exploration.
“A lot of the applications of soft robots are human-centric, so of course it’s important to think about safety,” says Daniel Vogt, M.S., a research engineer at the Wyss Institute. “Vacuum-based muscles have a lower risk of rupture, failure and damage, and they don’t expand when they’re operating, so you can integrate them into closer-fitting robots on the human body.”
Funding for this research project came from the Defense Advanced Research Projects Agency (DARPA), the National Science Foundation (NSF) and the Wyss Institute for Biologically Inspired Engineering.