Inspired by the biomechanics of cheetahs, researchers have developed a new type of soft robot that is capable of moving more quickly on solid surfaces or in the water than previous generations of soft robots.
The fastest soft robots until now could move at speeds of up to 0.8 body lengths per second on flat, solid surfaces.
The new class of soft robots, which are called “Leveraging Elastic instabilities for Amplified Performance” (LEAP), are able to reach speeds of up to 2.7 body lengths per second. This is more than three times faster – at a low actuation frequency of about 3Hz, the researchers from North Carolina State University note.
Characteristics
These new robots are also capable of running up steep inclines, which can be challenging or impossible for soft robots that exert less force against the ground. These “galloping” LEAP robots are approximately 7 centimeters long and weigh about 45 grams.
The new soft robotics are also capable of grabbing objects delicately, or with sufficient strength to lift heavy objects. This, according to the researchers, opens up potential applications in search and rescue technologies (where speed is essential) and industrial manufacturing robotics, among other sectors.
Cheetahs are the fastest creatures on land, and they derive their speed and power from the flexing of their spines.
“We were inspired by the cheetah to create a type of soft robot that has a spring-powered, ‘bistable’ spine, meaning that the robot has two stable states,” says Jie Yin, an assistant professor of mechanical and aerospace engineering at North Carolina State University and corresponding author of a paper on the new soft robots.
He explains that they have can switch between the stable states rapidly by pumping air into channels that line the soft, silicone robot. This releases a significant amount of energy, allowing the robot to quickly exert force against the ground. It enables the robot to gallop across the surface, meaning that its feet leave the ground. “Previous soft robots were crawlers, remaining in contact with the ground at all times. This limits their speed.”
Proof of concept
The researchers also demonstrated that the LEAP design could improve swimming speeds for soft robots. Attaching a fin, rather than feet, a LEAP robot was able to swim at a speed of 0.78 body lengths per second, as compared to 0.7 body lengths per second for the previous fastest swimming soft robot.
The researchers note that this work serves as a proof of concept, and are optimistic that they can modify the design to make LEAP robots that are even faster and more powerful.
