Raptor is not the first robot to sport legs with prosthetic blades, either. Another biped running robot, Athlete, built several years ago, also used carbon-fiber running blades.
Still, Raptor stands out for its simplicity, showing that it's possible to achieve significant speeds with an uncomplicated design.
Unlike other legged robots that rely on multiple actuators, Raptor uses just one motor per leg, which consists of a nine-bar linkage. To recover part of the energy used to make the robot move, the researchers added Achilles tendons that work as springs, absorbing and restoring energy with every step.
The robot's control system is also simple. Raptor runs a computer program known as a running pattern generator, which controls gait and speed.
The KAIST team is currently working to optimize their robot. They're interested not only in achieving ever-greater speeds, but also improving control and stability.
We've seen other legged robots take their first steps on treadmills and then learn to walk outside the lab. One example is HyQ, a quadruped from Italy. And then, of course, there's Boston Dynamics' WildCat (the successor to Cheetah), which was seen in a video bounding and galloping in a parking lot.