Carnivorous pitcher plants have inspired the creation of a slippery surface that not only is more slippery than Teflon but have self-healing and self-cleaning qualities, said scientists of Harvard University.
The newly created biomaterial could repel oil and water and could be used to make anti-graffiti and anti-icing surfaces as well as coat the inside of oil pipelines to prevent biofouling, said Lead researcher Dr Tak Sing Wong.
The research is published in the journal Nature.
The carnivorous pitcher plant has deep pitcher-shaped leaves which have rims, known as peristomes. These peristomes have a super-lubricated surface that makes them extremely slippery, thanks to which their prey lose footholds easily and drown in pitcher's digestive fluid.
The slipperiness of the pitcher surface is created by the overlap of cells that create a series of step-like ridges and troughs. When troughs collect the nectar secreted by the plant, ridges prevent it from draining away. As a result the plant's surface becomes so smooth and slippery that the oils get stuck on the feet of insects and makes them easy prey of the carnivorous plant.
The SLIPS Formation
Wong, in his research, attempted to create the same omniphobic surface which will repel not only water but also blood and crude oil and will be more slippery than its natural counterparts and man-made materials like Teflon.
Teflon, however, was previously listed in the Guinness Book of World Records for being the most slippery solid material in the world.
Wong assembled stacks of tiny posts, each a thousand times thinner than a human hair, and similarly thin fibers to get a rough structure. The structure was then filled with a nectar-like lubricant perfluorinated fluid 3M Fluorinert FC-70, manufactured by the firm 3M, which mixes with neither water nor oils, and barely gets evaporated.
We call it SLIPS, because everything does, Joanna Aizenberg of Harvard University said, whose lab designs and builds biomimetic materials to solve a range of problems.
The SLIPS are like sponges with solid blocks to trap liquids. SLIPS will firmly hold the liquid in place, but keep its surface smooth and flat which will help it to repel a greater range of liquids than any other man-made surface, scientists said. And in case of any damage to the material, SLIPS can self-heal by flowing fluid instantly into cracks or dents.
SLIPS are really easy to make and would be quite cost-effective, Aizenberg told C&EN.
Researchers hope SLIPS will prove to be significantly useful for producing low-friction oil and water transport pipes, for making self-cleaning windows and work surface and safe and efficient blood repellent devices.
In the recent past, researchers tried to mimic the lotus effect but, according to Wong, the pitcher plant effect would have more advantages over lotus as production of SLIPS does not depend on mechanical fabrication and its performance is based on the lubricant, not on a solid that has chances to damage.
However, efficiency of SLIPS will be tested with time but now the U.S. researchers are planning to further verify the performance of SLIPS at high temperatures and in humid conditions.