Researchers abuzz over bees carrying tiny gadgets

Using teeny, tiny batteries and sensors, insects provide a valuable eye in the sky for agriculture.

In the latest buzzworthy contribution to the Internet of Things, engineers at the UW have created a sensing system small enough to ride aboard a bumblebee.

Because the insects are fueled with their own food—as opposed to mechanical drones that require power of some sort—only a tiny rechargeable battery is needed to run the sensors. And it can do so for seven hours of flight and then recharge while the bees are in their hive at night.

“We showed for the first time that it’s possible to actually do all this computation and sensing using insects in lieu of drones,” says Shyam Gollakota, an associate professor in the UW’s Paul G. Allen School of Computer Science & Engineering and one of the faculty leads on this project. “(Small mechanical) drones can fly for maybe 10 or 20 minutes before they need to charge again, whereas our bees can collect data for hours.”

The researchers were drawn to bumblebees because they are tiny, highly efficient and present in many ecosystems. While they’re out doing their own work drinking nectar and gathering pollen, they could also be helping with precision irrigation and providing environmental sensing. They outshine mechanical drones because their energy is stored in fats and carbohydrates, providing much higher energy mass density than a drone’s batteries.

The research team outfitted three species of bumblebees commonly found on the East and West coasts with a microelectronic package weighing 102 milligrams—the weight of about seven grains of uncooked rice. Since the battery is 70 milligrams, the rest of the sensor equipment had to stay around 30 milligrams. Still, that was enough to include sensors to measure temperature as well as humidity and light intensity. Though honeybees are the primary workers for most crops that need pollination, the bumblebee is growing in use, particularly in greenhouse farming.

While they can fly longer than drones, bees aren’t the perfect sensor carriers. They can only carry small payloads, which limits the size of sensors and precludes the use of power-intensive GPS. To counter that, engineers came up with a power-free method to know where the bees were going. Multiple antennas broadcast signals across a specific area. A receiver in the bee’s backpack uses the strength of the signal and the angle difference between the bee and a base station to triangulate the insect’s position.

Also, it is hard to control where the bee might go. But that might also be valuable. “It would be interesting to see if the bees prefer one region of the farm and visit other areas less often,” says co-researcher Sawyer Fuller, an assistant professor in the UW Department of Mechanical Engineering. “Alternatively, if you want to know what’s happening in a particular area, you could also program the backpack to say: ‘Hey bees, if you visit this location, take a temperature reading.’”

This isn’t the first insect endeavor for Fuller and Gollakota’s labs. Their teams also recently collaborated on “RoboFly,” the world’s first fly-sized drone that does not need a wire from the ground to supply power and control signals. And their students already had some practice putting backpacks on bees, having recently done a similar sensor-load experiment. The process of attaching the pack involves chilling the bumblebee in a freezer for a few minutes to slow its movement, and then gluing on the unit of sensors and battery. A similar process is used to remove the device.