Scientists want to blanket the Earth in sensors. Their secret weapon? Moths

Researchers want to study every square inch of planet Earth. But not every square inch of planet Earth is easy to study. Some areas are challenging for humans to get to in order to monitor. What’s the answer? According to investigators from the University of Washington, the solution is staring us right in the face: Why not use flying insects, such as moths, to place sensors in locations that would ordinarily be difficult to reach?

OK, “placing” sensors may not be entirely accurate. The idea, instead, is to use insects as a flying platform for carrying tiny, lightweight sensors, weighing less than one hundredth of an ounce. This insect-borne sensor can be strapped in place using a small magnetic pin, surrounded by a thin coil of wire. When the insect is in the right location, the researchers remotely trigger the coil to create a magnetic field by generating a current that runs through it. This causes the magnetic pin to pop out of place, and the sensor to safely plunge from a height of up to 72 feet without breaking. It’s the equivalent of a drone delivery or a military supply drop — but, you know, with really small living bugs.

University of Washington researchers have created a 98-milligram sensor system — about one tenth the weight of a jellybean — that can ride on the back of a moth. Shown here is a Manduca sexta moth with the sensor on its back. Mark Stone/University of Washington

“Dropping things from the air is a great way to get things into hard-to-reach places,” Vikram Iyer, a doctoral student in electrical and computer engineering at the University of Washington, told Digital Trends. “This is a strategy people use in disaster scenarios to deliver food and medical supplies, and is usually done with large planes or helicopters. That got us thinking, can we use this same idea with much smaller drones, or even live insects, to release sensors across a large area?”

For the most part, dropping a piece of high-tech equipment the equivalent of six floors is bad news. But by making their sensors weigh about the same as a toothpick, even without a parachute they’re light enough that they don’t get damaged in the fall. Iyer likened it to how an ant could survive a fall from the top of the Empire State Building.

Once on the ground, the sensors can then be used to record information such as temperature or humidity (and, in the future, maybe more).

Insects: The platform of the future

Perhaps surprisingly, the University of Washington isn’t the only place interested in repurposing bugs for high-tech uses. Far from it, in fact. The Defense Advanced Research Projects Agency (DARPA) has flown rhinoceros beetles around like miniature RC helicopters. Other research labs have expanded on the notion of remote-controlling insects to create cyborg beetles. They control the signals transmitted to them so that the creatures speed up, slow down, take longer or shorter strides, and even change up their gait according to commands.

Then there are backpack-wearing, bomb-sniffing cyborg grasshoppers developed at Washington University in Missouri, previously described to Digital Trends as a “bridge between neuroscience and engineering.” That work has most recently received funding from the Office of Naval Research.

Mark Stone/University of Washington

It’s hard not to think that spy sensor-dropping armies of moths could have potential military applications. It’s difficult to imagine a more stealthy delivery platform for deploying surveillance sensors than a few harmless moths quietly fluttering through the sky. At present, though, it sounds like the applications are a bit more rooted in fundamental research.

While it’s early days for the project, the brilliance of the central idea is that it could be customized according to requirements — and the development of the necessary sensing technology to record whatever information you’re looking for.

How will it be used?

The researchers on the project believe that, using their unusual technique, it would be possible to effectively carpet bomb large areas with tiny sensors for monitoring data such as the conditions in a large area of forest. The sensing devices can transmit data at ranges up to 1 kilometer (0.6 miles), and consumes so little power that it has the potential to run for years on a single battery.

“Environmental research like maybe detecting the spread of forest fires or monitoring emissions over a large area are potential applications,” Maruchi Kim, another doctoral student who worked on the project, told Digital Trends. “Smart farms could also benefit from being able to quickly deploy things over a large area, as well as in spaces like industrial plants where you might have hard-to-reach places where you need to put a sensor. Another potential area is studying small animals or invasive species; you could attach this to something like a small bird or insect and use the onboard temperature sensor to release it when it gets to a nest, likely indicated by a temperature spike.”

Kim said the researchers are currently working with the Washington State Department of Agriculture to help track the invasive Asian giant hornet. “At the moment, we’re just using the wireless sensor part with the goal of following a live hornet back to a colony,” he said. “But in the future, we could add the release mechanism and drop the device once it reaches a nest.”

A paper describing the work, titled “Airdropping sensor networks from drones and insects,” was recently presented at the MobiCom 2020 conference.

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