Water hater speeds submarines

A surface that treats water droplets like so many air-hockey pucks has been developed by researchers at the University of California at Los Angeles. The surface reduces the friction between itself and water droplets by creating a cushion of air between the two acting like an air-hockey table. The big difference is that rather than a grid of air holes, the surface is coated with a forest of micrometer posts etched across the surface. The posts trap air allowing a fluid to flow across it with greatly reduced friction, it is almost like an inverted hydrofoil effect. Such a scheme has been tried before, but the UCLA researchers have the sharpest posts and the highest yet density of posts so far. This is important for certain areas for fluid research and for prospective microfluidic applications, as well as for making submarine craft more efficient by reducing drag.