See the New 'Cheetah' Robot That Now Runs Faster Than Usain Bolt

The running robot developed by the Pentagon's research arm DARPA and aptly named Cheetah for its speed was already the fastest robot on four legs, but now it has surpassed even Usain Bolt -- the fastest human.

Cheetah recently was clocked running at 28.3 miles per hour in a 20-meter split, according to DARPA's press release. Bolt's 2009 world record, on the other hand, is 27.8 mph in a 20-meter split.

Watch Cheetah achieve this feat:

DARPA acknowledges that Cheetah may have had a slight advantage though as it was running on a treadmill.

Constructed by Boston Dynamics for DARPA's Maximum Mobility and Manipulation (M3) program -- part of research for the Department of Defense -- Cheetah is being uniquely studied because of its legs. As DARPA points out in its press release, most robots use wheels or treads, which are not as well suited for a variety of terrains. Although legs may have an advantage, coordinating mechanical legs is more difficult and they can be slow.

"Modeling the robot after a cheetah is evocative and inspiring, but our goal is not to copy nature. What DARPA is doing with its robotics programs is attempting to understand and engineer into robots certain core capabilities that living organisms have refined over millennia of evolution: efficient locomotion, manipulation of objects and adaptability to environments,” Gill Pratt, DARPA program manager, said in a statement. “What we gain through Cheetah and related research efforts are technological building blocks that create possibilities for a whole range of robots suited to future Department of Defense missions.”

Since Cheetah is designed for a smooth treadmill and part of the program goal is for movement natural terrain, Gizmodo reports Dr. Alfred Rizzi, chief robotics scientist at Boston Dynamics, saying the outdoor version -- WildCat -- will begin testing in 2013.

The ultimate goal for WildCat will be to "[move] freely outdoors while [running] fast," Rizzi said.