The tiny microfliers, whose development by engineers at Northwestern University was detailed in an article published by Nature this week, are being billed as the smallest-ever human-made flying structures.  

Tiny fliers that can gather information about their surroundings  The devices don't have a motor; engineers were instead inspired by the maple tree's free-falling propeller seeds — technically known as samara fruit. The engineers optimized the aerodynamics of the microfliers so that "as these structures fall through the air, the interaction between the air and those wings cause a rotational motion that creates a very stable, slow-falling velocity," said John A. Rogers, who led the development of the devices.

"That allows these structures to interact for extended periods with ambient wind that really enhances the dispersal process," said the Northwestern professor of materials science and engineering, biomedical engineering and neurological surgery.

The wind would scatter the tiny microchips, which could sense their surrounding environments and collect information. The scientists say they could potentially be used to monitor for contamination, surveil populations or even track diseases.

Their creators foresee microfliers becoming part of "large, distributed collections of miniaturized, wireless electronic devices." In other words, they could look like a swarm.