Scientists created cyborg locust capable of sniffing out explosive vapors, which could one day be used by Homeland security to help search for bombs.
The team implanted electrodes into the creature’s antennal lobe, a region in the brain that receives input from its sense of smell, allowing them to see what scents it picks up.
Signals in the bugs’ brains reflected a range of vapor concentrations from TNT, DNT, RDX, PETN and ammonium nitrate -a chemically diverse set of explosives.
The neuronal activity of a locust exposed to an explosive smell was resolved into a discernible odor-specific pattern within 500 milliseconds.
The enhanced locust were created by a team at Washington University in St. Louise, who previously discovered the bugs’ olfactory system, or sense of smell, could be broken down as an ‘or-of-ands’ logical operation.
This allowed researchers to determine what a locust was smelling in different contexts.
Barani Raman, professor of biomedical engineering, said: ‘We didn’t know if they’d be able to smell or pinpoint the explosives because they don’t have any meaningful ecological significance.’
‘It was possible that they didn’t care about any of the cues that were meaningful to us in this particular case.’
Tests showed that the bugs could detect and discern between TNT, DNT, RDX, PETN and ammonium nitrate -a chemically diverse set of explosives.
‘Most surprisingly,’ Raman said, ‘we could clearly see the neurons responded differently to TNT and DNT, as well as these other explosive chemical vapors.’
Raman and his team designed an ‘odor box and locust mobile’ to see how well the locust can detect bombs.
The team pumped different vapors into a box and drove the creature around on top of a remote controlled car.
As the locust was driven around and sniffed different concentrations of vapors, researchers studied its odor-related brain activity.
‘You know when you’re close to the coffee shop, the coffee smell is stronger, and when you’re farther away, you smell it less? That’s what we were looking at,’ Raman said.
The next step was to optimize the system for transmitting the locusts’ brain activity.
In order to do not hurt the locust, the team conducted a new surgical procedure to attach electrodes that did not hinder the locusts’ movement.
The electrodes successfully captured the bug’s neuronal activity when exposed to an explosive smell and transformed it into a discernible odor-specific pattern within 500 milliseconds.
‘Now we can implant the electrodes, seal the locust and transport them to mobile environments,’ Raman said.
And the team hopes the breakthrough might be used by Homeland Security in searching for explosives.
‘The idea isn’t as strange as it might first sound,’ Raman said.
‘This is not that different from in the old days, when coal miners used canaries.’
‘People use pigs for finding truffles. It’s a similar approach — using a biological organism — this is just a bit more sophisticated.’