Graphene-lined garments could become the chemical-free solution against mosquito bites

Graphene has attracted a lot of attention because of its potential uses in everything from solar cells to flexible phone screens, the researchers touting it as a "supermaterial" that will radically alter the future of physics and physics. engineering. The latest research on the promising material has uncovered another particularly interesting application (forgive me for pun intended) for this mosquito repellent material.

In an article entitled Prevention of mosquito bites through graphene barrier layers, Researchers at Brown University have discovered that this material can be a two-part defense against mosquitoes. First, the ultra-thin material creates a physical barrier that the trunk – the appendages that mosquitoes use to acquire their "blood meal", as the researchers say, can not puncture. Surprisingly, their experiments also showed that graphene could be responsible for blocking the chemical signals used by mosquitoes to detect the starting point of their next meal, acting essentially as a kind of "force field" against insects. carriers of diseases.

"Mosquitoes are vectors of important diseases around the world, and protection against the bites of non-chemical mosquitoes is attracting a lot of interest," Robert Hurt, a professor at the Faculty of Engineering, said in a statement. Brown. "We had been working on fabrics that incorporated graphene as a barrier against toxic chemicals, and we started to think about how such an approach might be good, and we thought that graphene might also protect mosquito bites. "

To test this theory, the researchers recruited participants whose arms were covered with either graphene oxide (GO) films covered with a layer of stamen, or simply stamen. Those who had the graphene layer received no sting, while the other group was "feasted". The most interesting thing was that the mosquitoes completely changed their behavior when they were buzzing around graphene covered subjects.

"With graphene, the mosquitoes did not even land on the skin patch – they just did not seem to care about it," said Cintia Castillho, Ph.D. student at Brown and the lead author of the study. "We had assumed that graphene would be a physical barrier to sting, thanks to the resistance to puncture, but when we saw these experiences, we started to think that it was also a problem. a chemical barrier preventing mosquitoes from detecting the presence of someone. "

From there, they continued the experiment by dabbing human sweat over the graphene barrier, which caused the mosquitoes to flock to these areas as they normally would on human skin.

While all of this is promising, there is still a long way to go before graphene can be used as an effective mosquito shield, for example for camping gear. The experiments also found that the material had an Achilles heel: water. When it was wet, graphene oxide lost just about all of its repellent properties against mosquitoes. The researchers found that another form of graphene oxide (GERO) with reduced oxygen content was effective against wet or dry mosquitoes, but that this material variant was not breathable, this that does not really help in real applications.

"GO is breathable, which means you can sweat through it, while rGO is not," said Hurt. "So, our preferred embodiment of this technology would be to find a way to stabilize GO mechanically so that [it] stay strong when it is wet. This next step would give us all the benefits of breathability and bite protection. "