The world's fastest land animal, cheetahs run by rapidly flexing their spines between two stable states. A consortium of American scientists recently set out to replicate that motion in a soft robot. The resulting device is known as LEAP, which stands for "Leveraging Elastic instabilities for Amplified Performance."
Instead of muscles and a biological spine, the silicone-bodied robot incorporates two soft pneumatic actuators and a flexible spring-loaded mechanical spine. Alternately pumping air in and out of the two actuators causes energy to be stored and suddenly released, triggering the spring to instantly flex the spine from one stable state to another. As a result, the bot is able to exert force against the ground, leaping off of it.
Utilizing this technique, LEAP is able to gallop at a rate of up to 2.7 body lengths per second across flat, solid surfaces.