"With the graphene, the mosquitoes weren't even landing on the skin patch — they just didn't seem to care," said Brown Ph.D student Cintia Castillho, who is the study's lead author. "We had assumed that graphene would be a physical barrier to biting, through puncture resistance, but when we saw these experiments we started to think that it was also a chemical barrier that prevents mosquitoes from sensing that someone is there." In the study, researchers covered the arms of participants in either graphene oxide films covered by cheesecloth or just cheesecloth. Those who were covered in graphene didn't receive a single bite.
Unfortunately, graphene oxide becomes far less effective when wet, which is exactly the type of environment where mosquitoes thrive. Scientists found that mosquitoes were able to puncture through graphene oxide films that were soaked in water. But when they used graphene with reduced oxygen content (rGO), they discovered it worked as a bite barrier in both dry and wet conditions.
One drawback is that rGO isn't breathable, so it's unlikely to be used in camping clothing. Scientists hope to find a way to stabilize graphene so it remains strong when wet. "This next step would give us the full benefits of breathability and bite protection," said Brown University professor Robert Hurt.
If you're curious about graphene, you won't have long to wait. Makers of outdoor gear and electronics are already adding graphene to jackets, battery packs, shoes and more.