In the near(ish) future we could be using cyborg locusts as sniffer dogs to detect explosives, according to a new proof of concept study. A team showed that locusts could smell different amounts of explosive chemicals in the air to track the location of a bomb, and these detections can be picked up by reading their brain waves.
As clever as we humans like to think we are, nature keeps outdoing us with better versions of our own inventions. So why reinvent the wheel when we can just build on natural versions of these instruments instead? Sniffer dogs are one of the most common examples, with their powerful noses picking up traces of drugs, explosives or other contraband. But could locusts perform the same kind of job?
Researchers at Washington University in St. Louis have found a way. Locusts have an incredibly keen sense of smell, and their brain waves produce a certain pattern after they detect a particular scent. Once they’ve been trained to recognize a smell, reading their brain waves could be a solid indicator if the desired smell turns up in a sample or in the environment.
In previous work, the team showed that locusts can be trained to detect a smell in much the same way as you’d train a dog. The researchers sprayed the scent of hexanol into a cage, just before feeding time. Sure enough, after a few rounds of training, the smell alone would make the insects act like they were anticipating food.
For the new study, the team tested how well locusts could detect vapors from different explosives, such as TNT, DNT, RDX, PETN and ammonium nitrate. They fine-tuned a previous system they’d developed to read the patterns of firing neurons in the locust brain to reveal whether the insects had detected the trained scent.
By surgically attaching electrodes to the locusts, the researchers could record their brain waves without getting in the way of the insects’ movement. They found that the electrodes could register that the locusts had detected the desired odors within 500 milliseconds.
In the next experiments, the researchers tested whether locusts could locate a bomb by figuring out which direction the odor was coming from. To do so required an unusual setup – a robot car carrying the locust inside a clear plastic box.
The explosive vapors were piped into the box at a certain place, and the vehicle was moved up and down the length of the box. Sure enough, as the locust got a whiff of the different concentrations of the vapors, its brain waves would get comparatively stronger.
The researchers say that they’re almost at the phase where Homeland Security and other organizations could use locusts to search for traces of explosives.
The research was published in the journal Biosensors and Bioelectronics: X.
