Researchers at Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and Harvard's Wyss Institute for Biologically Inspired Engineering have harnessed energy from a toy popper and used its buckling capability, or the sudden loss of structural stability, to build fast-moving, inflatable soft actuators.
"Soft robots have enormous potential for a wide spectrum of applications, ranging from minimally invasive surgical tools and exoskeletons to warehouse grippers and video game add-ons," said Benjamin Gorissen, a postdoctoral fellow at SEAS and co-first author of the paper. "But applications for today's soft actuators are limited by their speed."
As such, researchers developed an actuator integrated into a fully soft robotic system to give soft robots the ability to crawl, walk and swim as well as the ability to jump. This could enable robots to navigate safely through uncharted landscapes or places where humans cannot reach.
When toy poppers buckle, it is known as shell buckling. The team designed the actuators with two spherical caps — essentially two toy poppers — connected at a base. When the actuator inflates, pressure build up between the two poppers and the outer cap expands while the thicker inner cap buckles and collapses, hitting the ground and launching into the air.
Although the device is simple, it could be fundamental in the future, controlling and optimizing soft robot performance.
Researchers were able to characterize and control the pressure volume relationship between the two shells to develop a soft robot capable of releasing a specific amount of energy repeatedly. The approach can be applied to any shape and any size, meaning it could be used in healthcare as a medical device to puncture a vein or in large exploratory robots that traverse uneven terrain.
The full research can be found in the journal Science Robotics.
