Textured surfaces improve performance of condensers

Using a new technique that allows the behaviour of liquids on solid surfaces to be studied in more detail than has been possible previously, the team has designed a surface that water droplets can move across extremely fast, which could increase the rate that desalination plants produce fresh water and improve energy efficiency in electricity production.

The team, part of a research group led by Kripa Varanasi, MIT professor of ocean utilisation, has designed a surface with features around 10 microns across — around the size of a red blood cell. This surface is coated with a very thin layer of an oily lubricant that is held in place by the capillary action of the tiny spaces between the features — effectively, they pin the lubricant down, Varanasi said. Water droplets zip across this surface like pucks on an air-hockey table with ‘crazy velocities’, he added — some 10,000 times faster than droplets on an unpatterned surface.