Small, convenient mosquito repellent device passes test to protect military personnel

A device developed at the University of Florida for the US military provides protection against mosquitoes for an extended period and requires no heat, electricity or skin contact.

The controlled-release passive device was designed by Nagarajan Rajagopal, Ph.D. candidate and Dr. Christopher Batich in UF’s Department of Materials Science and Engineering in the Herbert Wertheim College of Engineering. It was recently successfully tested in a four-week semi-field study at the US Department of Agriculture in Gainesville in collaboration with Dr. Daniel Kline, Dr. Jerry Hogsette and Adam Bowman of the USDA’s Center for Medical, Agricultural and Veterinary Entomology.

Results showed that the controlled release of the repellent transfluthrin was effective in preventing several species of mosquitoes from entering the test site. Transflutrin is an organic pesticide considered safe for humans and animals.

“Our device eliminates the need to apply topical repellents and insecticides that are sprayed across an open area, which can contaminate surrounding plants or bodies of water and have a negative impact on beneficial pollinators such as bees and butterflies,” said Rajagopal. “This is versatile, portable, easy to deploy and does not require electricity or heat to activate the solution.”

Mosquitoes are more than an annoying distraction for the military, as they can spread serious diseases and viruses such as malaria, dengue virus, Zika and West Nile virus. The DOD is continually looking for ways to protect soldiers in the field from mosquitoes.

The passive controlled release device consists of a tubular polypropylene plastic that is 2.5 centimeters long and contains two smaller tubes and cotton containing the repellent. The team attached 70 of the devices to the opening of a large military tent using fishing line. and nothing to a similar control tent. Caged mosquitoes were released at various points along the outside of the tent, and nearly all were killed or repelled within 24 hours, Rajagopal said.

He explained that while the field test showed that the team’s prototype created a protective space from mosquitoes for four weeks, the final product, which will be built using a 3-D printing process, could extend that period to three months.

“We call our device passive because you don’t need to do anything to activate it,” he said. “It provides a sustained release of the pesticide over an extended period rather than just a spike at the beginning.”

Rajagopal said they are applying for a patent on the device, and the government is interested in further study so that it can eventually be commercialized for the civilian market. USDA scientists believe there are more opportunities for its use by people who enjoy outdoor activities.

“While initially developed for tent entrance protection, the personal protective device in various sizes and configurations has potential for other applications, including for hiking and fishing,” said Kline, a research entomologist at the USDA.

Kline added that they will evaluate other active ingredients besides transfluthrin to expand its potential.

“It doesn’t stop with mosquitoes,” Rajagopal said. “We want to show that it will work with other insects, especially ticks, which pose a threat by causing Lyme disease.”