A drone equipped with an antenna from a male moth can locate the source of a smell more accurately than any electrical sensors. Unfortunately, however, the only smell it can detect is the sex pheromone emitted by female moths.
Electrical sensors for odours are commonly used to detect gas leaks, but these are relatively slow to react to smells and even slower to reset between measurements, says at Shinshu University, Japan. 鈥淚t鈥檚 very difficult to apply that to the drone and odour tracking,鈥� he says. 鈥淪o we use a very high-speed sensor, and that鈥檚 the insect antenna.鈥�
Terutsuki and his colleagues created a 鈥渂io-hybrid drone鈥� designed to navigate aided by smell, like insects, rather than relying entirely on sight. The researchers had previously created a prototype that could detect smells from up to 2 metres away. Their new robot has a funnel-like cover to the sensor to make detection more directional, and it is programmed to rotate with periodic pauses to create a clearer map of nearby smells. The researchers say it now has a range of up to 5 metres 鈥� more than double the previous version.
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In tests, it was able to autonomously fly towards a smell source. But because the antenna is taken from a male silkworm moth (Bombyx mori), it is finely tuned for a specific chemical, known as , which is the聽sex pheromone emitted by female moths of the species.
Terutsuki admits that this ability is of limited use, but says the prototype is just a proof of concept. Further research will focus on using sensors from mosquitoes, which have evolved to detect mammals that the insects can feed on. Terutsuki says this could lead to autonomous drones that can track down survivors trapped in rubble after earthquakes.
But there are more pressing problems to solve first. For instance, the antennae have a short lifespan and the conductive gel used to connect them to electrical components 鈥� like that used in ultrasound tests 鈥� dries out after around 5 hours.
npj Robotics
