Graphene in Textiles for Vector Protection

Arthropod transmitted diseases can have a significant impact on Military readiness. To limit exposure to disease carrying arthropods, the US Military uses the Department of Defense (DoD) Insect Repellent System, which calls for proper wear of a treated uniform, using topical repellent on exposed skin, taking prophylaxis, and sleeping under a bed-net. Both the US Army and Marine Corps use insect repellent treated uniforms. These treatments do provide an initial level of protection to the Warfighter but degrades with laundering and wear. With the rising threat of vector-borne diseases, there is a need to enhance protection to Warfighter through improved uniforms. Work completed by Brown University showed that dry graphene or graphene oxide nano-films interfered with host-seeking behavior of Aedes aegypti mosquitoes. The specific aim of this effort is to expand upon this knowledge and to develop military-specific textile technologies to reduce exposure to arthropod bites without degrading the desired properties of uniform materials. Early efforts demonstrated proof of concept of two approaches: 1) a polymer-based process was demonstrated by loading various levels of graphene within nylon 6,6 and pressing into films; and 2) the print-based process used a syringe printer to print graphene pastes on the back side of untreated fabric. Efficacy testing was conducted by tracking mosquito landings and bites on the samples. Currently there are difficulties with the extrusion of fibers for the polymer-based process and the data is inconclusive due to the low graphene loading level in the successfully extruded fiber. The printing-based approach is proving successful as the graphene print patterns afforded a significant reduction in the number of bites as compared to a control fabric, however, in terms of landings, the data is more variable, but trending towards reductions in landings.