Similar in size to a grain of sand, this flying microchip could someday monitor air pollution, track the spread of airborne diseases, and, of course, conduct surveillance. While its inventors at Northwestern University call it the "smallest-ever human-made flying structure," it's actually inspired by propeller seeds that fall from trees, catching the wind as they spiral to the ground. From Northwestern Now:
By studying maple trees and other types of wind-dispersed seeds, the engineers optimized the microflier's aerodynamics to ensure that it — when dropped at a high elevation — falls at a slow velocity in a controlled manner. This behavior stabilizes its flight, ensures dispersal over a broad area and increases the amount of time it interacts with the air, making it ideal for monitoring air pollution and airborne disease.
As the smallest-ever human-made flying structures, these microfliers also can be packed with ultra-miniaturized technology, including sensors, power sources, antennas for wireless communication and embedded memory to store data.
"Our goal was to add winged flight to small-scale electronic systems, with the idea that these capabilities would allow us to distribute highly functional, miniaturized electronic devices to sense the environment for contamination monitoring, population surveillance or disease tracking," said Northwestern's John A. Rogers who led the device's development. "We were able to do that using ideas inspired by the biological world. Over the course of billions of years, nature has designed seeds with very sophisticated aerodynamics. We borrowed those design concepts, adapted them and applied them to electronic circuit platforms."[…]
But what about all the electronic litter? Rogers has a plan for that. His lab already develops transient electronics that can harmlessly dissolve in water after they are no longer needed — as demonstrated in recent work on bioresorbable pacemakers. Now his team is using the same materials and techniques to build microfliers that naturally degrade and disappear in ground water over time.