High-tech slippery coating helps toilets shed all the gross stuff

The spray-on coating could save water across the globe.

Amanda Kooser
Freelance writer Amanda C. Kooser covers gadgets and tech news with a twist for CNET. When not wallowing in weird gear and iPad apps for cats, she can be found tinkering with her 1956 DeSoto.
Amanda Kooser
2 min read

Toilets with a super-slippery coating would require less water to flush.

Wong Laboratory for Nature Inspired Engineering, Penn State

Toilets have long been a target for water conservationists concerned about the amount of liquid they use for each flush. A new coating technology could mean future loos will require much less water than their current low-flow counterparts.

Penn State University researchers are behind this innovation. "Our team has developed a robust bio-inspired, liquid, sludge- and bacteria-repellent coating that can essentially make a toilet self-cleaning," said engineer Tak-Sing Wong. The team published a study Monday on the new coating in the journal Nature Sustainability.

Just in case you're super-squeamish, the video demonstration of the new coating contains footage of "synthetic fecal matter."

The liquid-entrenched smooth surface (LESS) coating is sprayed on in two steps. "When it dries, the first spray grows molecules that look like little hairs, with a diameter of about 1,000,000 times thinner than a human's," said co-developer Jing Wang. The second spray acts as a lubricant. 

The coating takes about five minutes to cure and can last for up to 500 flushes before the lubricant layer needs to be reapplied.

The researchers say toilets across the globe consume 141 billion liters of water each day. The use of the coating could potentially reduce that by up to 50%. The coating could also be applied to improve sanitation for toilets that don't use water.

LESS is already on its way to the market through Spotless Materials, a company created to commercialize the product. 

The hydrophobic spray can be used on other surfaces, including mirrors, sinks and automotive windshields. That sounds like an appealing prospect for anyone who doesn't enjoy cleaning chores. Just spray LESS on and spend less time scrubbing. The late-night infomercial practically writes itself.

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