Skip to main content
Move the World.
Scientists Engineered “Cyborg Grasshoppers” to Sniff out Bombs

Lead image courtesy of McKelvey School of Engineering / Washington University in St. Louis.

A far tinier, far more futuristic critter might replace dogs as the preferred explosive detection animal: cyborg grasshoppers.

With funding from the U.S. Office of Naval Research, scientists at Washington University in St. Louis have found a way to hack into the insects' sense of smell, in the hopes of using the bugs to detect explosives, according to a paper published on the preprint server bioRxiv.

No Nose, No Problem

While the human sense of smell starts with our noses, grasshoppers use receptor neurons in their antennae to detect odors in the air. Each antenna can contain 50,000 neurons, and whenever they detect a scent, they send an electrical signal to a part of the insect's brain called the "antennal lobe."

To tap into this system, the scientists implanted electrodes into grasshoppers' antennal lobes. They then exposed the insects to different odors — including the explosive TNT and DNT, a compound used to produce TNT — and found that the different scents activated different neurons in the grasshoppers' antennal lobes.

Researchers created tiny backpacks for the grasshoppers, each containing a sensor that could wirelessly transmit the data from the insect’s brain electrodes to a computer.

By analyzing the electrical signals detected by the brain electrodes, the scientists could determine when a grasshopper was smelling TNT, DNT, or one of the controls used for the experiment (hot air and a chemical found in bitter almond oil).

Smell Test

The next step in the research was seeing how this ability to read the scent signals in a grasshopper's brain could prove useful for explosive detection.

For that, the researchers created tiny backpacks for the grasshoppers, each containing a sensor that could wirelessly transmit the data from the insect's brain electrodes to a computer.

A grasshopper wearing a tiny backpack containing a sensor that can wirelessly transmit data from the insect's brain electrodes to a computer. Researchers hope to use the insects' sense of smell to detect explosives. Photo courtesy of McKelvey School of Engineering / Washington University in St. Louis.

A grasshopper wearing a tiny backpack containing a sensor that can wirelessly transmit data from the insect's brain electrodes to a computer. Researchers hope to use the insects' sense of smell to detect explosives. Photo courtesy of McKelvey School of Engineering / Washington University in St. Louis.

Though the backpacks were lightweight, they were still heavy enough to immobilize the grasshoppers, so the team placed the insects on remote-controlled platforms. They then drove the platforms around to different locations.

By analyzing an individual cyborg grasshopper's brain activity, the researchers could pinpoint the locations with the greatest concentrations of explosives with 60% accuracy. When they took into account the brain activity of a group of seven grasshoppers, that accuracy jumped up to 80%.


The research has some clear limitations.

For one, after the researchers implanted the electrodes into the grasshoppers' brains, they only had a seven-hour window to use the insects for explosive detection before the bugs became fatigued and died.

Additionally, the researchers didn't test the cyborg grasshoppers' ability to detect explosives when multiple scents were in the air, which would likely be the case during real-world deployment.

Still, according to the researchers' paper, this is the first time anyone has demonstrated a way to combine a biological olfactory system with technology to detect chemical odors — and that approach could avoid a couple of problems with current methods.

Sniffin' Ain't Easy

Despite trying for decades, scientists have yet to develop a machine that can match the odor-detecting abilities of animals — an artificial nose simply can't compete with a biological one.

This is the first time anyone has demonstrated a way to combine a biological olfactory system with technology to detect chemical odors.

Some animals are better than others when it comes to sniffing out scents, and while it would be great if we could use bears — the animals with the best sense of smell — for explosive detection, dogs have historically proven to be the ideal combination of talented and trainable scent detectors.

The problem is that training an explosive detection dog (and its handler) is expensive and time-consuming, and the current supply of trained dogs can't meet the demand.

Additionally, recent reports have indicated that trained dogs are sometimes subjected to deplorable conditions and abuse, leading some of the animals to die before they even complete a year's worth of work.

If scientists can figure out how to efficiently use tech to tap right into the brains of grasshoppers to know when bombs are nearby, the cyborg bugs could end our reliance on dogs for explosive detection — and this study is the first indication that that might be possible.

Up Next

Drugs
This High Schooler Created a Drug Discovery Search Engine
drug discovery
Drugs
This High Schooler Created a Drug Discovery Search Engine
While looking for drugs to potentially fight Alzheimer’s, a high school researcher's AI did “comically” bad, until he thought of it as a search engine.

While looking for drugs to potentially fight Alzheimer’s, a high school researcher's AI did “comically” bad, until he thought of it as a search engine.

Archaeology
After 360,000 Years, Extinct Cave Bear's DNA Is Still Readable
cave bear dna
Archaeology
After 360,000 Years, Extinct Cave Bear's DNA Is Still Readable
Scientists have sequenced the DNA from the ear bone of an ancient cave bear, an extinct relative of the polar and brown bears.

Scientists have sequenced the DNA from the ear bone of an ancient cave bear, an extinct relative of the polar and brown bears.

Transportation
Electric Garbage Trucks Are (Quietly) Coming
electric garbage trucks
Transportation
Electric Garbage Trucks Are (Quietly) Coming
With Mack Truck’s electric garbage trucks set to be delivered in 2021, your mornings may be getting quieter soon.

With Mack Truck’s electric garbage trucks set to be delivered in 2021, your mornings may be getting quieter soon.

Future of Science
Researchers are Rushing to Freeze... Lab Mice Sperm?
Lab mice
Future of Science
Researchers are Rushing to Freeze... Lab Mice Sperm?
With their labs closing and the future unclear, researchers are sending precious cargo — the sperm of lab mice — to be frozen and stored.

With their labs closing and the future unclear, researchers are sending precious cargo — the sperm of lab mice — to be frozen and stored.

Uprising
What's Special About Cancer-Killing Nanobots? Precision.
medical nanobots
Uprising
What's Special About Cancer-Killing Nanobots? Precision.
These tiny, robotic machines can deliver drugs directly to infected cells, and they're changing the future of medicine.

These tiny, robotic machines can deliver drugs directly to infected cells, and they're changing the future of medicine.

Superhuman
Can Virtual Reality Help Fight the Opioid Crisis?
Can Virtual Reality Help Fight the Opioid Crisis?
Watch Now
Superhuman
Can Virtual Reality Help Fight the Opioid Crisis?
VR has long been seen as an escape from the real world. But recently researchers have been putting an unexpected twist on that. They’re now exploring how VR could provide an escape from an unfortunate reality many face everyday: chronic pain.
Watch Now

Opioid addictions have become a dangerous side effect for many that take medications to treat chronic pain. To address this, doctors are exploring alternatives to prescriptions pain medicine. As part of this movement, Dr. Brennan Spiegel at Cedars-Sinai Hospital in Los Angeles has spear-headed some pretty fascinating research. He and his team are using virtual reality to reduce pain. Not only is it surprisingly effective...

Coded
Meet the Digital Bodyguard for Investigative Journalists
Meet the Digital Bodyguard for Investigative Journalists
Coded
Meet the Digital Bodyguard for Investigative Journalists
Smári McCarthy discusses his job protecting the work of journalists investigating organized crime and corruption
By Mike Riggs

Smári McCarthy discusses his job protecting the work of journalists investigating organized crime and corruption

The New Space Race
Tiny Satellites With a Huge Impact
Tiny Satellites With a Huge Impact
Watch Now
The New Space Race
Tiny Satellites With a Huge Impact
Many satellites are nearing the end of their life. This is what could be next.
Watch Now

Spire’s CubeSat satellites—each about the size of a shoebox—can collect and transmit weather data six times as often as the massive, billion-dollar satellites we’ve used for generations. But it doesn’t stop at weather prediction. Spire thinks their tech will be essential as humans journey deeper into deep space.

Robotics
Will Robots Steal Our Jobs?
Will Robots Steal Our Jobs?
Robotics
Will Robots Steal Our Jobs?
Could exoskeletons help us do our jobs? Should we actually be afraid of robots taking our jobs? These are the...
By Mike Riggs

Could exoskeletons help us do our jobs? Should we actually be afraid of robots taking our jobs? These are the latest stories from the frontlines of the robotic world.