January 10, 2011

A Liquid Repellent BioFilm

Your next Phone, Mac, PC, Watch, Car, Yacht etc could be coated with a liquid repellent biofilm made up of living bacteria. The biofilm provides super liquid resistance and will protect the object on which it is coated. In nature, another material with similar water-repellent properties is the Lotus Leaf.

Water bead on Lotus leaf via NPL

While studying bacteria, engineers at Harvard’s SEAS found that the bacterial biofilms had an incomparable ability to repel not just water but also repel a wide range of liquids including alchohol and acetone. The study should lead to water resistant biofilms, perhaps for your next phone, Mac, PC, Watch, Car or Yacht. It should also yield ways to eliminate harmful biofilms that clog pipes, contaminate water supply and contaminate food preparation.

Water resistant Biofilm

The bacterial biofilm’s surface (shown above) is a “resilient meshwork made from proteins and polysaccharides and assembled into a multiscale, hierarchical structure” which gives it the strong liquid repellent property. It is also strong enough to repel antimicrobials such as ethanol or acetone, which is why antimicrobials are unable to act against such biofilms. The photo below shows an ethanol bead formed on the biofilm.