Researchers designed Kengoro to sweat through its frame in order to cool all 108 of its motors. (via ieee)
Calling JSK Labs’ Kengoro a ‘workout machine’ is an incredibly accurate term and its stamina while exercising is literally inhuman. While the robot is certainly impressive looking, it is the way it cools itself that’s truly remarkable, as it does so like us human’s do- it sweats. The Kengoro robot is the next iteration of human-like robots JSK Labs designed to mimic human functions, coming after Kojiro and Kenshiro before him.
Humans generate heat when using their muscles, especially while doing intensive work and as a result, the body cools itself using sweat, which evaporates off the body thereby cooling it in the process. Humanoid robots such as Kengoro and his siblings rely on high-torque motors to move instead of muscle tissue. As a result, using traditional cooling methods- heat sinks or fans are not adequate enough to cool the motors and thereby limit the amount of time the robot can function.
In this case, engineers often turn to water-cooling to solve the heat issue, however in Kengoro’s case, this only adds weight and takes up valuable space in or on the robot, which again, would only limit its functionality. As it stands, Kengoro is packed to the gills with circuit boards, gears, flexor tendons/rods and 108 individual motors to make it move and has little room for anything else, including radiators to help cool the heated parts. Therefore, the researchers from JSK Labs took on a different, novel approach to the problem and designed an ingenious solution to cool the robot using 3D printing.
Kengoro’s skeleton is actually laser-sintered aluminum powder with a permeable channel built inside that allows deionized water to enter the porous areas and evaporate, keeping the heated motors cool.
For Kengoro, the researchers decided to use the robots frame as a passive, system-wide cooling solution that can effectively cool all 108 of the robot’s motors. To accomplish this feat, the researchers turned to 3D printing or more accurately metal laser sintering (additive manufacturing), to fuse aluminum powder to create the internal skeleton. By alternating the energy level during the sintering process, the researchers were able to control the metal’s permeability, keeping the focus on those areas where heat is generated.
In order to get a ‘controlled sweat’ instead of puddles of water everywhere, the researchers focused on the porous openings during the fabrication process, creating smaller channels nearer to the center of the robot’s bone structure and slightly larger channels nearer the surface. This regulates the flow of water that’s excreted during the robots movements and allows the water to evaporate on the surface of the skeleton, cooling the motors in the process without any moving parts or use of a radiator and tubing.
Of course, it’s not a better solution over using a radiator assembly as Kengoro can’t function endlessly using his integrated sweating platform but he can run half a day on one cup of water before needing a refill. Doing any strenuous activity like pushups limits that time to just 11-minutes, still that’s pretty impressive for passive solution.
Have a story tip? Message me at: cabe(at)element14(dot)com