Tiny Sticky-Wheeled MicroTug Robots Can Pull 2000 Times Their Own Weight

Imagine going to the water's edge, wading into the sea, and dragging out...a blue whale. And not an easy to wrangle (comparatively speaking) baby blue whale either, but a fully grown, mature mammalian beast of the sea. This is the equivalency being offered to describe the astounding power of the oh-so-small MicroTug robot.

Designed by engineers David Christensen and Elliott Hawkes at the Biomimetics and Dextrous Manipulation Lab at Stanford University, MicroTugs are tiny robots — some just a measly 9 grams — that are capable of pulling objects that tip the scales at 2000 times their weight.


Taking inspiration from nature, MicroTugs borrow from techniques in use by gecko lizards and inchworms. Their incredible strength comes from their wickedly sticky wheeled feet, which employ an adhesive that requires an extremely low amount of contact force and that can engage and disengage many times a second.

The wheeled feet of a MicroTug are covered with microscopic rubber spikes that can bend and stick to a surface, and each time the robot picks its feet up the spikes detach and straighten out to allow movement. And like the inchworm, MicroTugs move one foot forward while keeping the other back to support the load.

A winch built into the MicroTug is used to briefly pull whatever object the tiny robot has in tow, which provides it with some slack to incrementally move forward using its wheels. As such, by repeating the process ad nauseam a MicroTug can pull huge objects without much trouble.

Christensen speaking to an interviewer said, "We are looking to bring the adhesive to market first, but then applications like these will be certainly of interest along with a ton of other things. It's pretty magical stuff to play with. Like a tape that can be turned off and on like a light switch but without any power or electronics." He went on to say that the next step would involve "looking at ways to make multiples of them work together as a team, and scaling the technology up to larger bots with more industrial parts and a whole lot more force".

The MicroTugs will be featured at the International Conference on Robotics and Automation set to take place from May 26-30 in Seattle.

Images and video provided by Biomimetics and Dexterous Manipulation Lab, Stanford University