Thanks to its feathery fluff, a dandelion seed riding the wind can cover more than half a mile. While disheartening for many gardeners, this marvel of passive travel was an inspiration for scientists at the University of Washington. The UW researchers have created tiny devices that are dispersed with the breeze, settling across a landscape where they can monitor and report back on environmental conditions.
The team readily credits nature for shaping their work, which they’ve dubbed the “internet of bio-inspired things” in a riff on IoT technology.
In the future “you’re going to have a melding between biology and technology where you have the best of both worlds,” said Shyam Gollakota, a UW professor in the Paul Allen School of Computer Science & Engineering who helped develop the sensors.
The dandelion-mimicking devices are the focus of a paper published Wednesday by Gollakota and colleagues in the journal Nature.
Earlier research by the UW scientists focused on insect-tech fusions. They developed tiny tracking tools that were attached to giant so-called “murder” hornets, leading investigators with the Washington Department of Agriculture to their nests, which were then destroyed. The engineers have also deployed wireless cameras on the backs of beetles and built sensors that can be dropped from moths.
At the time, the bug work was groundbreaking and the researchers surprised themselves with what they could accomplish, Gollakota said. Ultimately, those projects laid the foundation for this latest cutting-edge innovation, which had to solve for multiple technical challenges. The insects, for example, can manage much heavier payloads than the dandelion-inspired devices, which only weigh 30 times more than a 1 milligram dandelion seed.
“You don’t know what is possible,” Gollakota said, “until you’re pushing at boundaries.”
Vikram Iyer, a UW assistant professor in the Allen School, is the lead author of the paper in Nature, a top scientific journal. UW biology professor Thomas Daniel and UW electrical and computer engineering graduate Hans Gaensbauer are co-authors. Gollakota is senior author.
Here’s how the devices work:
- Thin, perforated film discs carry mini electronics including a solar panel; a capacitor to store charge overnight; at least four sensors that monitor conditions such as temperature, pressure, humidity and light; and a microcontroller to run the system.
- Hundreds or thousands of the devices are released, likely by a drone. In dry, breezy conditions they can travel up to 300 feet before landing.
- Just as a dandelion seed naturally lands seed end-down, the device needs to land solar panel-up. Thanks to engineering tricks, that happens at least 95% of the time with the devices. Due to weight constraints, it has no battery.
- The sensors collect and relay information while solar powered during daylight.
- The system sends the data to researchers using “backscatter,” which employs radio technology and reflects transmitted signals. This uses less power than a device that generates its own signal.
The researchers say the devices offer a time- and labor-saving strategy for monitoring conditions on farms, forests and other scenarios.
The technology is not ready for commercialization, and the price of the devices is unknown. The hardware costs about $2-3 per unit.
The scientists are exploring the possibility of creating the discs out of a biodegradable material to reduce the environmental impact. They’re also experimenting with its shape to better control where the sensors land and to ensure an even distribution. One strategy is to intentionally including multiple shapes so devices naturally travel different distances.
“This is mimicking biology, where variation is actually a feature, rather than a bug,” Daniel said in a statement. “Plants can’t guarantee that where they grew up this year is going to be good next year, so they have some seeds that can travel farther away to hedge their bets.”