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Deadly pitcher-plant inspires super slippery nano-surface

posted 5 Feb 2012, 05:34 by Mpelembe   [ updated 5 Feb 2012, 05:35 ]

Researchers at Harvard University have created a technology that makes almost any surface liquid-repellant. The scientists say their creation, inspired by a carnivorous lotus plant, could be adapted for a variety of uses, from water-proofing fabrics in the home to improving the efficiency of oil pipelines. Sharon Reich has more.

REUTERS/HARVARD UNIVERSITY - Red wine on a table cloth usually means the end of the table cloth.

But soon, according to scientists at Harvard University, that will no longer be the case. They've developed a transparent coating called SLIPS - Slippery Liquid-Infused Porous Surface - that will repel all kinds of liquids from cabernet to crude oil.

Researcher Tak Sing Wong say SLIPS is a thin film that can be tailor-made to protect almost any porous surface from liquid penetration.


"Because of this thin lubricating film it creates an amazing property of oil repellant and water repellant characteristics. What we are seeing here, when I spray water on the surface it just gets repelled, similar to the lotus type surfaces. What is interesting is that if I put drops of crude oil on pitcher plant-inspired surfaces, you see it doesn't really... stick on the surfaces, it just all gets repelled,"

The idea was inspired by the carnivorous pitcher plant, which uses surface microtextures and slippery walls to trap its prey.

Team leader, Joanna Aizenberg says the plant was the ideal model.


"To survive it has to catch insects of all kinds. To do that it created a very interesting strategy, very rough surface that is impregnated, lubricated with water. So the moment insects with their oily feet step on the pitcher plant they're actually hydroplaning, they immediately slide into the digestive juices of the organism so that they don't have to do anything to trap them," Aizenberg explained.

The team has mimicked the plant's properties by infusing nano material with a lubricating fluid. The result is a surface free of defects. Even when damaged and scraped with a knife or a blade - the material instantly repairs itself and continues to repel liquids.

Experiments with ants demonstrate the success of the technology. When filmed walking inside a vial they're unable to maintain their grip on the treated surface.

The researchers say the coating can also withstand extreme environments and temperatures. Coupled with its low manufacturing cost, Aizenberg says SLIPS is ideal for improving efficiency and energy loss in areas where there are currently no solutions.


"Big problems that we are looking at is oil transport and really pipes, where liquid can go through without any energy penalties for driving them through this. We are applying high pressure to push through, it could be used in district heating."

Other areas where SLIPS could be used range from medical applications to the food and restaurant industries where stain-forming liquids can cost businesses millions in cleaning costs.

Professor Aizenberg says the commercialization of SLIPS is still years away, but for companies - and red wine drinkers - a water-proof solution is in sight.

Sharon Reich, Reuters