Just like our own muscles, when motors are active for long periods of time, they start to overheat. Usually, this requires some sort of cooling system, but these are often large and bulky, limiting the construction of lightweight moveable robots. Now researchers in Japan have come up with a novel solution. Meet Kengoro: the slightly creepy-looking humanoid robot that can sweat.
Built by the University of Tokyo, Kengoro is a highly advanced piece of kit. Powered by more than 100 individual motors, the robot is incredibly flexible, versatile, and strong. But the problem arose of how to stop the dozens of motors that power it from overheating, while keeping the amount of tech on the robot to a minimum. Usually, the support structures (or “skeleton”) only serve the one function – keeping the robot upright. So the researchers decided to see if they could add another function to it, inspired by our very own cooling system of perspiration.
By building the frame out of laser-sintered aluminum powder, the team was able to precisely control the structure of the skeleton. This basically involved using lasers to fuse the aluminum powder into a solid, meaning that it could be created as dense or as porous as the researchers required, and this was the key to the novel cooling system. Some areas were created with low permeability, to give strength, while others were formed with high permeability with holes and tunnels, to channel the liquid.
Not only that, but the degree of permeability was also controlled, being less porous on the inside of the “bones” and more porous on the outside. This means the water moves in the direction the researchers wanted, from inside to out, where it would evaporate and cool the robot, whilst preventing it from dribbling all over the floor. The water used in the system was no ordinary tap water either, but deionized water, with just one cup of the stuff needed for Kengoro to run for about 12 hours without overheating.
This impressive new cooling system gives the bio-inspired Kengoro far more endurance than other robots of its kind. The robot can go for 11 minutes straight doing pushups without the need to stop, which is pretty good going for a humanoid machine. It's surely only a matter of time before it'll be pumping iron in the gym.