Considered a pesky insect by many, but a source of bioinspiration by scientists, Pennsylvania State University researchers have made miniature omnidirectional sources of light and optical sensors based on the compound eyes of fruit flies.
There’s a good reason why so many of us fail to hit our target when taking swatter to fly: their compound eyes. Arranged in a hexagonal convex pattern, compound eyes consist of hundreds of optical units called ommatidia, which together provide flies a nearly 360-degree field of vision, explains the American Institute for Physics (AIP). A team of researchers at Pennsylvania State University has now turned to this unique structure to create miniature light-emitting devices and optical sensors.
“We were inspired by those eyes,” Raúl J. Martín-Palma, an adjunct professor of Materials Science and Engineering at Pennsylvania State University told AIP. “We said, ‘OK, we can make something artificial using the same replicating structure to emit light in all directions, rather than what we have now, which is just planar, light-emitting diodes.’”
The researchers extracted corneas from flies and coated them with a well-known fluorescent polymer. To test the structure’s light-scattering properties, they then induced the modified surface to emit visible light by exposing it to diffuse ultraviolet light. When compared to a similarly coated flat surface, the modified ommatidia tended to scatter light more uniformly in all directions.
According to the news release, this increased emission and angular distribution means that the pattern of the fly’s cornea could soon be adapted into extremely minute light-emitting diodes and detectors, which would be able to process light output and input from a staggeringly wide field of vision.
The researchers have already developed a technique to mass-replicate biotemplates at the nanoscale, including compound eyes of insects. This means that instead of having to kill 50 flies to make 100 bioreplicated eyes, they can simply make multiple copies out of one template. Their next step is to expand the coating procedure to include other species’ compound eyes to identify the best structure for omnidirectional light emission.
Martín-Palma and his fellow researchers describe their bioinspiration work in the journal Applied Physics Letters, which is produced by AIP.