Humans evolved to walk on two legs, but getting robots there has proven quite challenging so far.

That's why it is amazing to see this bipedal robot, developed by the University of Michigan, walk without the help of a support beam.

The robot, dubbed MARLO, is more dexterous than its bipedal sister, MABEL, which was developed in 2008.

Although MABEL was the fastest bipedal robot with knees, reaching a 9-second gait, the robot had to be attached to a metal rod to keep lateral stability as it ran around in a circle pen.

MARLO, which looks like a Darth Vader helmet with legs and people feet, can walk in all directions and even go outside with no external help to keep balance.

"MABEL was constrained to one plane, which is not much different to old Mario games," says Brent Griffin, a researcher at the University of Michigan College of Engineering who's working on the two robots. "But when you go the full 3-D you need more control to handle the additional dynamics." Griffin also stressed to Popular Science that his views don't necessarily reflect those of his employer or his colleagues.