Engineers at MIT have found that an ultra-thin layer of aluminum oxide applied as a protective coating to metals can flow like a liquid instead of cracking. This allows it to fill in cracks and gaps, preventing leakage of the tiny molecules that can penetrate through most materials.
The trick is to apply the coating in sufficiently thin layers of about 2 to 3 nanometers (billionths of a meter) thickness. Its extraordinary ability to move as a liquid allows it to guard against stress corrosion cracking, which ordinarily would lead to structural failure. The potential applications are numerous in industries that have fluid systems.