Coatings // SLIPS-Based Antibiofilm Surfaces are Stable in Submerged, Extreme pH, Salinity, and UV Environments © Based on Material by Harvard University, USA

Researchers at School of Engineering and Applied Sciences, Harvard University, report in PNAS that Slippery Liquid-Infused Porous Surfaces (SLIPS) prevent 99.6% of Pseudomonas aeruginosa biofilm attachment over a 7-d period, as well as Staphylococcus aureus (97.2%) and Escherichia coli (96%), under both static and physiologically realistic flow conditions. They show that SLIPS-based antibiofilm surfaces are stable in submerged, extreme pH, salinity, and UV environments. Taking a completely different approach, the researchers used their recently developed technology, dubbed SLIPS (slippery-liquid-infused porous surfaces) to effectively create a hybrid surface that is smooth and slippery due to the liquid layer that is immobilized on it. SLIPS is also nontoxic, readily scalable, and most importantly, self-cleaning, needing nothing more than gravity or a gentle flow of liquid to stay unsoiled. As previously demonstrated with a wide variety of liquids and solids, including blood, oil, and ice, everything seems to slip off surfaces treated with the technology.

"People have tried all sorts of things to deter biofilm buildup–textured surfaces, chemical coatings, and antibiotics, for example," says Aizenberg, Amy Smith Berylson Professor of Materials Science at the Harvard School of Engineering and Applied Sciences (SEAS) and a core faculty member at the Wyss Institute for Biologically Inspired Engineering at Harvard. "In all those cases, the solutions are short- lived at best. The surface treatments wear off, become covered with dirt, or the bacteria even deposit their own coatings on top of the coating intended to prevent them. In the end, bacteria manage to settle and grow on just about any solid surface we can come up with."

Image: The word "SLIPS" is coated with the SLIPS technology to show its ability to repel liquids and solids and even prevent ice or frost from forming. The slippery discovery has now been shown to prevent more than 99 percent of harmful bacterial slime from forming on surfaces. © Joanna Aizenberg, Rebecca Belisle, and Tak-Sing Wong

Alexander K. Epstein, Tak-Sing Wong, Rebecca A. Belisle, Emily Marie Boggs, and Joanna Aizenberg: Liquid-infused structured surfaces with exceptional anti-biofouling performance, In: PNAS Early Edition, July 30, 2012, DOI: 10.1073/pnas.1201973109: http://dx.doi.org/10.1073/pnas.1201973109