Scientists develop innovative camera lens based on an insect’s eye
posted Thursday, May 2, 2013 at 12:21 PM EDT
The problem with currently available super wide-angle lenses is that the images come out extremely distorted towards the edges. But a new scientific development looks to the eyes of insects in order to get around this optical limitation.
Athropods (including insects) have compound eyes, which while much lower resolution than our own, have a significantly larger field of vision. They're made up of ommatidia, individual lenses paired with individual cones. An international research team has published a paper in Nature, and have replicated these bulging hemispheres of lenses using flexible technology.
The trick to create a lens that has this immense, 180° field of view without distortion is curving the sensors to match the array of lenses. John A. Rogers, a Swanlund Chair Professor at the University of Illinois at Urbana-Champaign, explains:
“Full 180 degree fields of view with zero aberrations can only be accomplished with image sensors that adopt hemispherical layouts – much different than the planar CCD chips found in commercial cameras. When implemented with large arrays of microlenses, each of which couples to an individual photodiode, this type of hemispherical design provides unmatched field of view and other powerful capabilities in imaging. Nature has developed and refined these concepts over the course of billions of years of evolution.”
To replicate the compound eyes, the researchers created an array of tiny lens/sensor pairs. While these were not flexible, the connections between each were. The sheet of lenses and sheet of electronics were connected while still a flat sheet, with "serpentine filament bridges" interlinking them. These bridges allowed for flexibility, and for the entire network of microlenses to be deformed into a hemisphere. The space between the lenses is filled with a black dyed elastomer to prevent light leaks.
The advantage to a lens system like this is that there's no distortion to speak of, and it has a near infinite depth of field — which could potentially make for radically new lenses for the likes of security and action cameras. The downside is the resolution — each lens/sensor pair is only a single pixel. The current generation of the device is only 180 pixels, about on par with a fire ant. However, some insects, like the dragonfly, have 28,000 lenses in their compound eyes. So while it may be a long way from being something you can use in day to day life, it's still a significant breakthrough in lens optics.