These small sensors not only look like dandelion seeds, they also fly through the air like this and could make agriculture more digital.
Using wireless sensors, temperature, humidity and other environmental factors can be measured and monitored far away from buildings and other infrastructure. This provides valuable information for agriculture and tracking climate change, among other things. However, if data is to be collected over large areas, such measurements have so far been expensive and time-consuming, since hundreds of the sensors have to be spread over a large area before measurements can begin.
Inspired by how dandelion plants disperse their seeds with the wind, a research team led by Vikram Iyer from the University of Washington in Seattle has now developed a tiny sensor-carrying device that can be carried by the wind. Although it is about 30 times heavier than a dandelion seed, it can be transported up to 100 meters by a moderate breeze. Once on the ground, the device, which can accommodate at least four sensors, uses solar cells to power its on-board electronics and can transmit sensor data up to 60 meters during the day.
Similar to a dandelion seed, the spokes arranged around a central point serve to slow down the fall and thus achieve the greatest possible flight distance. This makes the small device a highly efficient system: “Our prototype shows that a drone could release thousands of these devices with a single drop. They are all carried by the wind a little differently, and basically with that one drop you can create a network of 1000 devices,” reports senior author Shyamnath Gollakota.
Since the system works without batteries, it can in principle be used until mechanical damage occurs. A downside, however, is that the electronics are scattered throughout the ecosystem. The researchers are therefore investigating how these wireless sensors can be made more biodegradable.