- Scientists have developed a tiny, lightweight, shape-shifting platform that can hold a variety of environmental sensors and be dropped from drones to study far-flung locations.
- The design for the platforms, known as microfliers, was inspired by origami, the Japanese art of paper folding.
- Each microflier can snap between two shapes while in the air, allowing them to have different trajectories and thus disperse across a larger area when they land.
- Though they haven’t been used in any scientific studies yet, microfliers could be useful for the large-scale deployment of environmental sensors measuring and transmitting data on pressure, temperature, humidity, or lighting conditions, among others.
The next time you see a leaf gliding down from above, you might want to take a closer look. For all you know, what’s tumbling down could possibly be a new shape-shifting, sensor-laden platform built by researchers to carry out environmental monitoring.
Developed by scientists at the University of Washington, these tiny platforms are designed to be dropped from drones. By virtue of their ability to change shape mid-air, each of them ends up having a different trajectory during their descent, allowing a batch of them to spread out across a large area instead of clustering together in the same spot.
“A small change in shape actually has a pretty dramatic impact on how they move through the air,” Vikram Iyer, assistant professor of computer science and engineering at the University of Washington who led the team that developed the platform, told Mongabay in a video interview. “In one case, they have this tumbling descent, kind of like a leaf flying in the wind, and then in another case, when they have just a little bit of an inward fold, they pull basically straight down like a parachute.”
It was the blending of ancient tradition and modern technology that allowed the researchers to design the platform. Origami, the Japanese art of paper folding, inspired the researchers to come up with the shapes, folds and creases in the flat and square body of the lightweight platform. They then used an electromagnetic actuator to allow it to change shape electronically in mid-air.
“Essentially, these are little origami robots where the origami allows them to snap between two different folded shapes,” Iyer said. “We can program each one to change its shape at a different time or even at different altitudes, and get them to actually spread out over a large area.”
In a study, led by Iyer and published in the journal Science Robotics, the team laid out how the solar-powered origami microfliers, as they call them, were able to switch between two shapes in a matter of just 25 milliseconds — about four times as fast as the blink of an eye. An actuator, the device that prompts the shape change, is triggered by a pressure sensor (which researchers monitor to gauge the altitude and subsequently activate the actuator).
Though the platform hasn’t been deployed for any scientific studies yet, Iyer said it could be effective for large-scale dispersal of environmental sensors, especially in far-flung places that are hard to reach. Each microflier can hold sensors to measure and transmit data on pressure, temperature, humidity, or lighting conditions, among others. As part of their research, Iyer and his team dropped microfliers from a drone at an altitude of 40 meters (131 feet), and observed them dispersing up to 98 m (322 ft) in light breeze conditions.
The idea of diminutive sensors that can be dispersed from the air has been around for a while. While some researchers have made progress in recent years, difficulties in controlling the descent of such sensors have always remained a challenge.
It was this hurdle that Iyer’s team overcame with their origami-inspired design. The decision to incorporate the Japanese technique was, in fact, fortuitous.
Some of Iyer’s students had been prototyping origami structures when they discovered, by accident, that the falling behavior of the platforms varied in each folded state. What ensued was months of work to figure out how to get the platform to change shape electronically, while also improvising the design to make it small, lightweight and battery-free. According to the study, the team designed a low-power electromagnetic actuator, used to control mechanical movements, which produced energy in a short period of time. This energy caused the platform to fold along its creases and alter its shape rapidly.
“This is inspired by the flight of leaves, only we’re actually taking a step beyond that and adding this element of active control where we can engineer these things to move in a way that we want,” Iyer said.
To ensure that the microfliers spread out over a wide area, the researchers trigger a few of them to change their shapes right under the drone. For a few others, they wait until they drop to a lower altitude so that they spread out further. Iyer said the sensors on the platform can work even when they’re in the air and in the process of falling down. “If you want to make measurements in a column of air at a high-spatial granularity, this can do that as well,” he said.
Next up for the team is to explore newer shapes and designs that could help the platform be used for a wider variety of applications. “Can we achieve finer-grained control by repeatedly moving back and forth between the two shapes?” Iyer said. “Can we actually get them to follow a precise trajectory?”
They’re also working to make the platforms biodegradable so that they can disintegrate and decompose once the work is complete. Iyer said he hopes to partner with biologists and ecologists in the near future to figure out how to tailor the microflier for specific scientific studies.
“Is there a different kind of sensor that we need to integrate? And how would the deployment scenario actually work?” he said. “These are all questions we are working on.”
Banner image: The platforms can carry environmental sensors and could be useful tools to disperse sensors in far-flung areas. Image by Mark Stone / University of Washington.
Abhishyant Kidangoor is a staff writer at Mongabay. Find him on 𝕏 @AbhishyantPK.
Citation:
Johnson, K., Arroyos, V., Ferran, A., Villanueva, R., Yin, D., Elberier, T., … Gollakota, S. (2023). Solar-powered shape-changing origami microfliers. Science Robotics, 8(82). doi:10.1126/scirobotics.adg427
