You can "drill" 5nm holes in aluminum oxide[1]. Which is pretty sweet, but calling that process "drilling" is a gross misnomer. The finest drills[2] out ther

You can "drill" 5nm holes in aluminum oxide[1]. Which is pretty sweet, but calling that process "drilling" is a gross misnomer. The finest drills[2] out there are measured in hundreds of nm, and still take several seconds to get through relatively thin material. To drill the billions of holes you'd need for a reverse osmosis membrane, you'd die before it was finished. [1] https://en.m.wikipedia.org/wiki/Anodic_aluminium_oxide https://en.m.wikipedia.org/wiki/Anodic_aluminium_oxide [2] https://www.tpc.toray/en/technology/hole/hol_005.html https://www.tpc.toray/en/technology/hole/hol_005.html