If you're trying to distribute environmental sensors over a wide area by dropping them from a drone, you definitely don't want them all landing in the same place. In order to keep that from happening, University of Washington scientists have created tiny origami "microfliers."
About the size of a large postage stamp and weighing just 414 milligrams, each microflier has a flat, flexible, square body to which various electronic components are attached. The latter include things like a microcontroller, Bluetooth chip, solar power-harvesting circuit, and pressure sensor.
What's more, utilizing a leaf-inspired type of origami known as Miura-ori, each flier's body is folded in such a fashion that it can pop back and forth between two states/shapes in just 25 milliseconds.
When the body is simply folded out flat, the microflier tumbles chaotically through the air as it falls, much like an elm leaf would do. This "flight pattern" allows it to cover a long horizontal distance on its way down – it can travel up to 98 meters (322 ft) if dropped from an altitude of 40 meters (131 ft) in a light breeze.
When the microflier's body is folded inwards, however, the device gently falls straight down – more like a maple leaf. Therefore, by getting individual fliers within one dropped batch to change from one state to another at different times, it's possible to have some traveling far out to the sides of the drop area, with others going right towards the center.
Each device changes state via an onboard electromagnetic actuator, which is in turn triggered by either the pressure sensor (when a certain altitude is reached), the Bluetooth chip (when an activation signal is received) or a timer in the microcontroller. The Bluetooth chip can also transmit recorded data.
Importantly, all of the electronics are powered by the solar circuit – no batteries are required. And what's more, a variety of environmental sensors could certainly be added.
"Our tiny microfliers can be used to monitor how temperature, lighting conditions, or other environmental factors vary across the atmosphere as they descend," lead scientist Prof. Vikram Iyer tells us. "Deploying swarms of such microfliers could help researchers paint a picture of what's happening for applications including digital agriculture and monitoring climate change."
Iyer also states that while the current prototypes aren't biodegradable, the team is working on developing microfliers that are – so they won't just indefinitely remain in the environment after being deployed.
You can see the fliers in flight, in the video below. A paper on the research was recently published in the journal Science Robotics.
Source: University of Washington
