Cool and comfortable mosquito-proof clothing could become available thanks to fabrics with special knits that the insects cannot penetrate.
Thin fabrics that block mosquito bites have been developed by experimenting with patterns made by knitting machines.
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| Mosquitoes’ mouthparts can easily penetrate most thin fabrics Borkin Vadim/Shutterstock |
John Beckmann at Auburn University in Alabama set out to create bite-proof clothing after garments he bought for a canoeing trip failed to protect him. “I got eaten alive,” he says.
Any clothing thicker than the length of a mosquito’s proboscis will prevent bites, Beckmann says, but this clothing isn’t suitable for warm climes where mosquitoes usually thrive.
His team started by testing the bite resistance of several popular clothing brands. Volunteers wearing the items placed their arm in a cage with mosquitoes and the number of bites were counted. None of the woven fabrics had any bite resistance but one knitted fabric had some.
Knitted fabrics consist of interconnected loops rather than criss-crossing fibres. Many clothes are made from micro-knitted fabrics made by machines that can be programmed to knit in different patterns. The team found a knit pattern known as interlock, where loops are positioned above each other, could block bites.
Increasing the thread width and decreasing the stitch length further improved bite blocking. Having a higher proportion of spandex over cotton or polyester in the yarn also helped. The researchers showed their blocking knits can prevent bites from at least two species, the small Aedes aegypti and the much larger Psorophora howardii.
As a mosquito probes the fabric, the loops close and prevent its proboscis getting through to the skin, Beckmann says. “If you can prevent them thinking they will get a blood meal, they will just fly away.”
Some blocking knits the researchers created were stiffer than standard fabrics, but they found one that is equivalent in comfort. The rights to the technology belong to Auburn University, and the aim is to license it to clothing companies.
“If I can buy a shirt that is equivalent in comfort and equivalent in price but also blocks mosquito bites, for sure I’d rather have that shirt,” says Beckmann.
It isn’t known what proportion of bites are through clothes rather than on bare skin, he says, but he hopes such clothing will greatly reduce the spread of mosquito-borne diseases such as dengue, zika and malaria. Beckmann also plans to test whether the blocking knits protect against other insects such as fire ants and deer flies, whose mouthparts are different from those of mosquitoes.
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