i must be missing something. the story says they had to:

1. put epoxy resin on each side of the graphene membrane to prevent swelling when exposed to water (which is important because if the graphene swells, then it allows sodium chloride to pass).

2. "drill" 1 nanometer (or smaller) holes into this membrane

so, what role does the graphene really play here? i mean, as long as you can drill tiny holes into it -- could the filter be made out of other material?