Japanese researchers cool robot by making it ‘sweat’

Scientists at the University of Tokyo have developed a robot called Kengoro, which cools down by a technique that follows the principle of sweating. By using porous material, the robot can repel water through its frame and allow it to evaporate, causing it to cool down.

The 170cm high and 56kg heavy Kengoro robot is equipped with 108 motors, all of which require cooling. Due to lack of space, there is no possibility to achieve this with radiators and fans. That’s why the scientists chose to use the robot’s frame for cooling purposes. They do this by sintering aluminum powder and using the resulting material for parts of the frame. For example, they can make certain parts of the frame water-permeable, writes IEEE Spectrum.

An inner porous layer allows the water to penetrate to the outer layer in certain places and evaporate there. This way of cooling is said to be three times more effective than cooling with air and a lot better than simply pumping water around in the robot. A radiator, on the other hand, would still be more effective than the ‘sweating’.

According to the makers of Kengoro, robot frames are often built to carry forces. In this case, the frame could perform additional functions, such as transporting water and releasing heat. The device needs about a cup of deionized water to function for half a day. For example, he can do 11-minute push-ups without his engines getting too hot.