A group of scientists at Stanford University just developed microbots, which they named μ Tugs, that are capable of moving incredibly heavy objects. For instance, 6 of the tiny bots were able to move an entire car. In order to pack strength and function into such a small robot, researchers looked to nature for inspiration. For strength, they studied ants, and for grip, they studied geckos.
Ants have the ability to move things, such as food, that significantly outweigh the ant’s body weight. Mechanical engineers working on the project produced a body that was similar to an ants, which allowed the μ Tugs to not be crushed by heavy objects. Then, the engineers encountered another problem, which was how to give the bots enough traction to do their jobs. Ants release a sticky substance from their foot pads, allowing them to find traction on the slipperiest surfaces. While this works for ants, creating a sticky substance for the bots would be messy, expensive, and impractical.
After ruling out the secretion of sticky gel, the team switched their focus to another animal with great grip: the gecko. Geckos have foot pads covered in microscopic hairs, and the pads of their feet spread apart with each step. The spreading creates a suction effect, and a small electrical force keeps the gecko connected to the wall its climbing. Physicists recreated a gecko like foot on the bots, by making small hairs out of silicone and using grooved rubber to create the foot pad. The resulting feet allow the bots to get a good grip on a surface, while also being able to release the suction with the help of their spring like legs.
The μ Tugs have truly incredible strength. At just over an inch long, half a dozen can tow wheeled vehicles, or carry up to 298 lbs. These specific bots outperformed many others that are also being developed. Their creators hope that the bots can aid rescuers in times of disaster by searching rubble and removing it, possibly saving lives. They also have the ability to open doors and open or close safety valves, which is an extremely useful trait in rescue situations.