MIT researchers have come up with a way to cool hot surfaces more effectively by keeping droplets from bouncing. Their solution: Decorate the surface with tiny structures and then coat it with particles about 100 times smaller. Using that approach, they produced textured surfaces that could be heated to temperatures at least 100 degrees Celsius higher than smooth ones before droplets bounced.
Through systematic studies using well-defined surfaces, they found that installing microscale silicon posts on a silicon surface raised the temperature at which droplets transitioned from landing to bouncing. But it worked best when the posts were relatively diffuse. As the posts got closer together, the transition temperature gradually dropped until it was no higher than that of a smooth surface.
In addition to nuclear safety systems, the work has important implications for systems such as steam generators, industrial boilers, fire suppression, and fuel-injected engines, as well as for processes such as spray cooling of hot metal.
Also: Learn about Two-Phase Electronics Cooling for Vehicle Applications .