Odor-detecting drone uses moth antennae

NAGANO, Japan >> Researchers in Japan have developed an odor-detecting drone that uses antennae taken from insects.

The “insect drone” can autonomously find its way to the source of an odor.

The researchers hope that by expanding the range of the drone’s odor detection, and ultimately enabling it to detect the scent of humans, the device can be a useful tool for search and rescue missions at disaster sites.

Female pheromones

Male silk moths are known to search for female moths by using their antennae to detect pheromones that the females emit.

Shinshu University associate professor Daigo Terutsuki, 36, a researcher at the Faculty of Textile Science and Technology, began investigating the use of the insect’s abilities in 2020 while working as an assistant professor at the University of Tokyo.

His research explored the possibility of using the moth’s abilities for scent tracking.

Terutsuki attached an antenna from a silk moth to electrodes and mounted it on a small drone to detect odors.

The information was converted into electrical signals, enabling the drone to fly autonomously to a pheromone source. A silk moth antenna can function for about five hours after being removed from an insect, he said.

The first drone that Terutsuki devised could search within a range of about 2 meters (about 6 1/2 feet).

He worked with a Chiba University expert on insect flight mechanisms to improve on the original drone, increasing the range to 5 meters.

One idea that helped them expand the range was inspired by the wingbeat of the silk moth. While researching, they discovered that when silk moths move their wings, they create air currents that move pheromones to their antennae.

The researchers likewise designed the rotation of the drone’s propellers to move odors toward a sensor connected to the antenna.

They also noticed the insect’s behavior of repeatedly stopping midair as it tracked the source of an odor. Inspired by this behavior, their drone does not fly in straight lines but stops midair at regular intervals and rotates 120 degrees to detect odors more accurately.

“This research couldn’t have been successful if we hadn’t gone beyond human thinking to learn from other organisms,” Terutsuki said.

Disaster scenes

The drone technology shows promise in aiding at disaster scenes. If a drone can be developed to detect human odor, it could be used to find people in need of assistance.

Using the results of their latest findings, Terutsuki and his fellow researcher are developing a sensor that employs mosquito antennae, which can detect human scent.

With a goal of putting their research to practical use, they interviewed firefighters and Self-Defense Forces personnel who had been involved in rescue missions after the disastrous 2011 Tohoku earthquake and 1995 Kobe earthquake, another deadly and destructive temblor.

“A drone can enter dangerous places that even disaster rescue dogs cannot go,” Teru­tsuki said. “This is the kind of technology that is needed out in the field, and we want to make it real by all means.”