March 19, 2025
NAGANO – Researchers at Shinshu University and another institution have developed an odor-detecting drone that uses antennae taken from living insects.
The “insect drone” can autonomously find its way to the source of an odor or pheromone. The researchers hope that, by widening the range over which it can detect odors and ultimately making it able to detect the scent of humans, they will turn the drone into a useful tool for search and rescue activities at disaster sites.
Pheromones from females
Male silkworm moths are known to search for female moths by using their antennae to detect pheromones that the females emit.
Shinshu University Associate Prof. Daigo Terutsuki, 36, a researcher at the Faculty of Textile Science and Technology, began researching how to utilize the insect’s abilities in 2020, when he was working as a special-appointment assistant professor at the University of Tokyo. He did serious research into the possibility of using these abilities for scent tracking.
Shinshu University Associate Professor Daigo Terutsuki, right, and another researcher show the odor-detecting drone on Feb. 19 at Shinshu University in Ueda, Nagano Prefecture. PHOTO: THE YOMIURI SHIMBUN
Terutsuki attached an antenna cut from a silkworm moth to electrodes and mounted it as an odor-detecting sensor on a small drone that measured 10 centimeters square.
Converting the information detected by the antenna into electrical signals made the drone able to fly autonomously to a pheromone source. An antenna can continue to function for about five hours even after it is cut off of an insect, said Terutsuki.
The drone that Terutsuki first completed in 2021 could only search within a range of about two meters.
This time, Terutsuki worked with another researcher, an expert on insect flight mechanisms from one of Chiba University’s Graduate Schools, to develop an improved version of the drone with a range of up to 5 meters.
One factor that helped them successfully expand the range was an idea gained from the wingbeat of the silkworm moth. During the research process, they discovered that, when silkworm moths move their wings, they create air currents that bring pheromones to their antennae.
They likened the rotation of the drone’s propellers to the flapping of the insect’s wings and designed the drone to bring odors to a sensor connected to an antenna.
They also paid attention to the insects’ behavior of repeatedly stopping in mid-air as they tracked the source of an odor. Inspired by this behavior, they had their drone not fly in straight lines but stop in mid-air at regular intervals and rotate 120 degrees each time so that it could detect odor sources more accurately.
“This research couldn’t have been successful if we hadn’t gone beyond human thinking to learn from other organisms.” Terutsuki said.
At disaster scenes
It is expected that this technology could be utilized at disaster scenes in the future. If a drone that can react to human odor were to be developed, it could be used to search for and find people in need of aid.
Using the results of the latest research, Terutsuki and his fellow researchers are developing a sensor that uses mosquitoes’ antennae, which can detect human scent.
Aiming to put their research to practical use, they interviewed firefighters and Self-Defense Forces personnel who had been involved in rescue activities following the Great East Japan Earthquake and the Great Hanshin Earthquake.
“A drone can enter dangerous places that even disaster rescue dogs cannot go,” Terutsuki said enthusiastically. “This is the kind of technology that is needed out in the field, and we want to make it real by all means.”