If ships' hulls are covered in barnacles and other marine organisms, then those ships have to work harder, burn more fuel, and create more CO2 emissions in order to move through the water. While there are anti-biofouling paints that kill such organisms, they can also harm other marine life. That's why scientists from Australia's University of Sydney Nano Institute have created a plant-inspired coating that keeps the critters from getting a foothold.
The carnivorous pitcher plant catches insects via an array of tiny structures around the rim of its opening. These structures trap a layer of water against the plant's surface, making the rim very slippery. As a result, insects that venture onto that rim slip and fall into the pitcher below, where they get digested in a pool of collected rainwater.
Led by Associate Professor Chiara Neto, the researchers duplicated those structures by adding so-called "nanowrinkles" to a transparent polymer surface. When non-toxic silicone oil was added, the wrinkles kept a layer of it held in place, even when submerged underwater.
In lab tests, samples of coated Teflon resisted almost all fouling from a common species of marine bacteria. By contrast, untreated control samples of Teflon were soon completely colonized by the bacteria.
The technology was also tested on samples attached to a shark net in Sydney Harbour, for seven weeks. Even in the harsher marine environment, the nanowrinkles still kept biofouling from occurring.
A paper on the research was recently published in the journal ACS Applied Materials & Interfaces. Scientists at Harvard University have previously created a pitcher plant-inspired slippery coating of their own, known as SLIPS.
Source: University of Sydney