Scientists at the University of Rochester have developed a laser etching technique that makes metals so water repellent droplets actually bounce off it. The technique uses a high power laser to etch a series of micro scale structures that make the surface highly hydrophobic.
The technique ensure that the hydrophobic effects doe not wear off like teflon or other surface coatings.
There are some very interesting potential defence and aerospace applications, icing free control surfaces for example. The technique is still ‘lab scale’ and takes hours to etch small areas but if it can be scaled there will be many defence manufacturers lining up with their cheque books (the work has been part funded by the USAF up to this point)
Read more here and watch the video below.
Would it work on a torpedo skin?