When you physically exert yourself hard enough, you break a sweat. You've probably noticed this. That dripping is a biological mechanism that keeps your body from overheating, because when the water secreted out of your sweat glands evaporates, it draws off heat and cools you down.
Now, if a machine does something strenuous, it has to get rid of the resulting heat energy too. In the past, engineers have relied upon fans, motors and radiators to cool robotic gadgetry, but those solutions are pretty bulky and cumbersome. And that's especially true if you're designing an anthropomorphic robot — a machine designed to resemble the human form.
That's why University of Tokyo JSK Lab researchers, who are designing robots with muscular and skeletal systems based upon the human body, have come up with an ingenious (or perhaps obvious) solution to the heat problem. They've created a robot named Kengoro that uses sweat to cool itself, employing a process called biomimicry, or taking inspiration from nature when designing technology.
Kengoro's technology was detailed in a presentation at the IEEE/RSJ International Conference on Intelligent Robots and Systems, held in Daejeon, South Korea, last month. An article on the website IEEE Spectrum explains that the five-and-half-foot, 123-pound (1.68-meter, 55.8-kilogram) automaton is stuffed with circuitry and motors — 108 motors, to be precise — that need to remain relatively cool to function optimally.
To do that, the Japanese scientists designed a system of channels in which water runs through the robot's body and then evaporates through its outer metal skin. Accomplishing that last trick required the engineers to 3-D print a highly permeable aluminum frame comprising a sponge-like array of tiny gaps and tunnels through which water can flow.
Kengoro has to be kept constantly hydrated for the cooling to be effective, just like you or me, but Kengoro only needs about half a cup of water per day, far less than a human. To demonstrate how well the sweaty robot works, researchers made it do pushups for 11 minutes straight, which it managed to do without burning up its motors.