Ring-bodied, light-powered robot makes its way up tracks like a cable car

Cable cars are certainly handy for transporting cargo up steep mountain slopes, but what if you want to do the same sort of thing on a smaller scale? Well, you could try using a tiny new light-powered robot, which is cable of carrying items up thin mid-air tracks. Developed by and colleagues at North Carolina State University, the "robot" is actually just a looped ribbon of light-sensitive liquid crystal elastomer. That ribbon has numerous twists in it, making it look a bit like a spiraled rotini noodle that's been formed into a ring.

When the robot is suspended on a horizontal or diagonal-sloping track – such as a wire or thread – it's placed so that the track runs through two or three consecutive twists in the ribbon. The rest of the bot hangs below the track. The cargo item in turn hangs from the bottom of the looped robot.



Upon being exposed to infrared light emitted from an overhead source, the section of elastomer that's located closest that source (the top section, through which the track runs) responds by contracting. As it contracts it also rolls, forming an auger-like screw-drive mechanism. That mechanism not only pulls the robot along the track, it also continuously moves light-exposed elastomer away from the light source while simultaneously drawing light- elastomer up the light.

In this fashion, the bot can indefinitely make its way along the track as long as the light source persists. In lab tests conducted so far, different versions of the robot have been able to move along both straight and curved tracks ranging in thickness from the width of a human hair to the width of a drinking straw. The bots could also make their way over track obstacles such as knots, climb slopes as steep as 80 degrees, and carry cargo over 12 times their own weight.

"We’re now thinking about specific applications for this technology, as well as adapting the soft robots to respond to inputs other than infrared light," says Yin. "For example, developing a soft ring robot that operates in sunlight or in response to other external energy sources." A paper on the research was recently published in the journal .

You can see the robot in action, in the video below. Source:.