North Carolina State University has developed motion technology for a new generation of soft robots. It significantly expands the speed range of such machines, which have never been different in speed. The secret of the novelty is in the bistable position of the body copied from cheetahs during movement.
The fastest running animal on the planet, the cheetah, has many secrets to achieving unprecedented speeds, one of which is the double position of the spine. It acts as a flexible beam, which first contracts and takes the shape of an arc, and then straightens and even bends in the opposite direction. In the first state, the limbs of the beast touch the ground, but during the transition to the second, energy is released and the cheetah jumps into the air, pushing off the ground and breaking the grip with it.
This is the most important point - the robot gets much less contact with the surface, it does not need to constantly overcome the friction force, like other soft machines that actually crawl on the ground. The cheetah robot jumps on it, and it is set in motion by air, which is forced into the flexible cavities of the body. But, unlike old designs, a bistable system does not have intermediate states, so while other soft robots inflate and deflate, the cheetah robot briskly changes its body shape and moves forward.
Previously, the speed limit for soft robots was 0.8 body lengths per second, and the cheetah robot accelerates to 2.7 body lengths per second. It operates at a 3 Hz creep rate and, due to its manner of movement, overcomes steep slopes much more easily. Even when driving underwater, the performance of the new item is 0.08 body length per second better than all competitors. The authors of the development believe that they will be able to accelerate the soft robot even faster, because so far they have simply reproduced the bistable mechanism, and have not purposefully worked on the chassis.