Japanese Research Team Creates Humanoid Robot that Sweats

Japanese Research Team Creates Humanoid Robot that Sweats

A humanoid robot developed by researchers at the University of Tokyo can sweat and uses this as a cooling mechanism. The motors of some robots generate heat and unless they have a way to cool themselves humanoid robots would not be able to work for longer hours. The robot named Kengoro can perform pushups for 11 minutes, as showcased by the tests conducted by the University of Tokyo team.

The research published by IEEE Spectrum showcases new ability of robots to keep cool and perform their tasks in a better way, without burning out their motor. The team added that bio-inspired robot Kengoro has been developed by 3D printing the frame of the robot. The variation in metal density and grooves in metal allow the robot to sweat.

Kengoro robot is the sixth robot developed by the research lab at the University of Tokyo. The team has also developed robots to help the elderly.

Generally, machines are cooled by fans, heat sinks or radiators. But to keep the weight of robot in control, researchers are looking at other methods of cooling motors, including usage of liquid cooled motors.

The robot weighs 56 kilograms and is 1.7 meter tall. The University of Tokyo’s JSK Lab project was led by Professor Masayuki Inaba.

Talking about the new strategy, Professor Inaba informed, “The approach goes way beyond just running water channels through the frame and circulating water through them, since that wouldn’t have solved the problem of needing to place a radiator in there somewhere. The researchers instead decided to try a passive technique, allowing the water to seep out through the frame around the motors to cool them evaporatively.”

"Usually the frame of a robot is only used to support forces," Research team member Toyotaka Kozuki told IEEE Spectrum. "Our concept was adding more functions to the frame, using it to transfer water, release heat, and at the same time support forces."

Kengoro robot has been showcased doing pushups in the video released by the research team.

The research paper further informed….

The approach goes beyond just circulating water through the robot’s frame. The researchers decided to allow the water to seep out through the frame around the motors to cool them evaporatively. In other words, the robot sweats.

Just like with a 3D printer, you get an enormous amount of control over the printing process, and by altering the energy density of the laser during fabrication, you can selectively vary the permeability of the metal that you’re making. A low permeability piece of metal would be something like a solid brick of aluminum, while a high permeability piece of metal would have a structure full of tiny gaps and tunnels, like a sponge. The laser sintering technique is precise enough to build up aluminum structures with areas of both low and high permeability, letting you make seamless metal components that have microchannels embedded in them through which water can flow.

Kengoro can run for half a day on about a cup of deionized water, although just like you, it has to keep itself hydrated for the cooling to be effective, especially if it’s working hard. Testing shows that this method of cooling works three times better than air cooling, and significantly better than just circulating water through the interior channel, although it’s not as effective as a traditional radiator using active cooling.