Tiny battery-free devices float in the wind like dandelion seeds

Inspired by how dandelions use the wind to distribute their seeds, a team has developed a tiny sensor-carrying device that can be blown by the wind as it tumbles toward the ground.

This system is about 30 times as heavy as a 1 milligram dandelion seed but can still travel up to 100 meters in a moderate breeze, from where it was released by a drone.

Once on the ground, the device, which can hold at least four sensors, uses solar panels to power its onboard electronics and can share sensor data up to 60 meters away.

To keep things light, the team used solar panels instead of a heavy battery to power the electronics. The devices landed with the solar panels facing upright 95% of the time. Their shape and structure allow them to flip over and fall in a consistently upright orientation similar to a dandelion seed.

These devices use backscatter, a method that involves sending information by reflecting transmitted signals, to wirelessly send sensor data back to the researchers. Devices carrying sensors — measuring temperature, humidity, pressure and light — sent data until sunset when they turned off. Data collection resumed when the devices turned themselves back on the next morning.

Another benefit of the battery-free system is that there’s nothing on this device that will run out of juice — the device will keep going until it physically breaks down. One drawback to this is that electronics will be scattered across the ecosystem of interest.