Scientists have developed a sieve which removes the salt from seawater.
The discovery by a UK research team could help provide clean drinking water for millions who need it.
At the moment the technique, using a graphene-based sieve, is limited to the lab - but it could one day prove invaluable.
Rahul Nair from the University of Manchester, who led the study, said: "It is a significant step forward and will open new possibilities for improving the efficiency of desalination technology."
The UN predicts that around 1.2 billion people, or 14% of the world's population, will experience difficulties sourcing clean water by 2025.
This new technology has the potential to revolutionise water filtration across the world.
It is hoped that graphene-oxide based systems can be built on smaller scales making it accessible to countries who do not have the funding to run large water plants.