Robots must be programmed to perform many of the tasks that living things take for granted—like, say walking from a hard surface onto a sandy one (such as stepping off a boardwalk onto the beach). For humans, shifting from a boardwalk to the beach, for example, requires but a minor adjustment to one's gait. But for a bot, a stroll along the beach—or in the desert—is no walk in the park. In fact, it can quickly turn into a sand trap, not a good thing (to say the least) if a robot is supposed to be delivering military or medical supplies in a war zone or collecting samples on Mars, millions of miles from Earth.

The reason robots struggle in sand (aside from it clogging up their mechanics) is that feet experience both solid- and fluid-like forces as they move through sand. Robots, of course, can't feel the difference; they need to be given instructions in order to adjust their movements. Understanding how these different materials impact a robot's footsteps is the key to building a robot that can easily adapt to changes in the surface it's traveling on, according to a new study by a team of Georgia Institute of Technology, Northwestern University, and University of Pennsylvania researchers that was published this week in the journal Proceedings of the National Academy of Sciences. (pdf)

Scientists at the Karolinska Institute (K.I.) in Stockholm report that they were able to make people perceive the bodies of mannequins and other people as their own. Their findings, published online this week by PLoS ONE, could help people suffering from body image disorders and be a boon for virtual reality developers to improve the control and realism of their systems and robot makers eager to create appendages that can more easily be remotely controlled.

"Our limbs and body always present themselves in certain orientations because our eyes are fixed to our skull," study co-authors Henrik Ehrsson and Valerie Petkova, both cognitive neuroscientists, write. But they note that if this visual perspective is changed, the mind can be tricked into believing that the body is in a different place, a condition exploited by virtual reality to make a person feel like he or she is flying a plane, driving a car or riding a rollercoaster while simply sitting in front of a computer or movie screen. (See this YouTube video of the experiments from the Associated Press)

Move over, HAL, there's an entire brigade of rock 'em, sock 'em robots in town. They're dexterous, graceful, and they can . . . dance?

This hot YouTube video features a bunch of hexapods (six-legged robots) getting down to the beat with choreographed bounces, splits and shimmies for the third annual hexapod robot dance contest.

Some of bots that competed also performed at halftime during robot soccer matches. I kid you not.

The dance-off was held back in the spring at Hagenberg Technical College in Austria, but has been getting a lot of buzz recently thanks to YouTube. (Video below.)

If even the thought of mounting a long staircase makes your knees ache, help could be on the way in the form of a supportive lower-body exoskeleton recently introduced by Honda Motor Co., Ltd. The company's walking assist device is designed to reduce the load on leg muscles and joints (in the hip, knees, and ankles) by supporting a portion of the wearer's bodyweight. It acts as an exoskeleton in that it straps over the wearer's clothes and provides two artificial legs that fit alongside the wearer's own legs.

The exoskeleton, which comes in small, medium and large sizes, weighs about 14.3 pounds (6.5 kilograms). The user secures it with a belt around the hip and thigh, then straps into a pair of shoes connected to it. A seat fits between the wearer's legs like a mini saddle. The device is powered by a lithium ion battery that lasts about two hours between charges, as long as the wearer isn't walking faster than 2.8 miles per hour (4.5 kilometers per hour).

In 1963, a decade before fictional TV astronaut and test pilot Steve Austin—aka "The Six Million Dollar Man"—was fitted with a bionic right arm and legs, researchers at Princess Margaret Rose Hospital in Edinburgh, Scotland, began developing electronic prosthetics to replace missing shoulders, wrists and hands. That technology is finally getting its due: Time magazine yesterday named i-LIMB Hand made by Touch Bionics one of the top 50 inventions of 2008.

Touch Bionics introduced the i-LIMB to the market last year. The prosthetic has five individually powered digits and is used by more than 400 patients worldwide, including at least five in the U.S. The i-LIMB Hand has myoelectric (muscle signal) controls that use electrical signals generated by the muscles in the remaining portion of a patient's limb to open and close its fingers. These signals are picked up by electrodes placed on the surface of the skin.