Don't judge a tiny robot by its size because these petite powerhouses can pull up to 2,000 times their own weight.
A pair of Stanford University PhD students at the school's Biomimetics and Dexterous Manipulation Lab have developed what they call MicroTugs, or mini bots that use adhesive power similar to what's found on the feet of geckos and ants to pull off incredible feats of strength.
One robot weighing less than a third of an ounce can carry a 2.2-pound weight vertically up a glass wall.
"This is equivalent to a human climbing up a skyscraper while carrying an elephant," David Christensen and Elliot Hawkes write on the lab's website.
Another robot weighs less than half an ounce, but can drag 2,000 times its own weight on a flat surface.
"This is the equivalent of a human adult dragging a blue whale around on land," the researchers note.
What's even more amazing is that the tests are actually bound by the limits of the actuators in the robots, not the adhesive power of the feet. That, the research team said in the video description, should allow them to pull almost twice as much -- or the equivalent of a human dragging two blue whales.
The tiny bots contain a battery, a winch, a processor, a motor, wheels and an adhesive layer on the belly. The adhesive layer contains small rubber spikes similar to the "setae" that cover the toes of geckos, NBC News reports.
As the video above explains, the adhesive layer doesn't stick unless the bot is pulling a load with its winch. When it does, the wheels lift and the belly lowers to stick to the surface. Once an object has been pulled, the adhesive belly lifts and the wheels come back down, allowing the robot to move freely again.
Eventually, the technology could be used on larger robots to carry heavy items around a construction site or in emergencies, such as bringing a rope ladder to someone trapped in a tall burning building, according to New Scientist.
The MicroTugs will be the subject of a presentation at next month's International Conference on Robotics and Automation in Seattle. The authors have also published two papers on their developments, which can be found here and here.