Bug eyes, bird eyes and human eyes all have one thing in common: They're round. Almost every ocular organ found in nature has some kind of curvature.
So why do all man-made cameras use flat lenses and inflexible silicon chips?
Taking nature as their guide, several scientists have developed a "bug's eye" digital camera directly modeled after those of insects, such as flies, ants and beetles.
The compound eyes found in most insects consist of long, cylindrical units called omatidia: a cornea connected to a photosensitive organ and surrounded with a dark pigment to prevent light from one lens leaking into neighboring lenses. These omatidia are clustered together in a dome shape with the lenses facing outward, and collectively, they form the compound eye of the insect.
"If you look at the design of the compound eye in the insect world and look at our device, there are really strict and explicit analogies between all the component parts," said John Rogers, a professor at the University of Illinois, explaining the process he and his fellow researchers used to creating their "bio-inspired" camera.
The finished camera's "omatidia" consist of a tiny microlens connected to a photoreceptive computer chip by an elastomer, or molecular compound with elastic properties.
Between 200 and 500 of these artificial omatidia are embedded in a sheet of curved and flexible rubber. "That corresponds to the number [of omatidia] you find in an ant or a common bark beetle," Rogers explained. "That's the low end of what you find in insects. The high end would be something like a praying mantis or a dragonfly, where the range [of omatidia per compound eye] is 10,000 to 20,000."
Producing a bug's eye camera of that resolution is possible, Rogers says, but it would require a finesse that the team simply couldn't achieve from their academic lab. Creating cameras with resolutions of "dragonfly and beyond," as Rogers puts it, would require the type of specialization available at state of the art manufacturing facilities.
The team's insect-inspired camera has multiple advantages over its flat-lens man-made counterparts, particularly when it comes to photographing multiple subjects simultaneously. With a field of view of 160 degrees, the camera can also capture landscape views without the peripheral distance and light distortion that are common in traditional wide-capture lenses.
Another of the camera's advantages is that the plastic sheet in which the omatidia are embedded is flexible, meaning it can be placed on both flat and curved surfaces or even blown up like a balloon to adjust its range of capture.
These features make the bug's eye camera well-suited to surveillance purposes such as security cameras or drones, Rogers suggested.
There's also room in the commercial camera market for cameras that eschew the traditional flat lens design. "One size does not fit all [when it comes to cameras], and the same thing will be true for man-made cameras … There may be opportunities for applications that require extremely wide field of view, which the insect world has mastered," Rogers told TechNewsDaily.
It'll probably be a couple of years before something like the bug's eye camera is available in commercial outlets. Meanwhile, Rogers hopes find new ways to apply nature's optical imaging systems to man-made technology. Lobsters and shrimp, for example, have eyes made of box-shaped receptors that help them gather visual information even in extremely low-light conditions.
You can read the research team's full report on their bug's eye camera in Nature scientific journal, published May 2.