Scientists make compound eye.

[Unorthodox]

http://www.bbc.co.uk/news/science-environment-22372442

Scientists make 'bug-eye' camera
The latest generation of stretchable electronics was key to achieving the curved shape Continue reading the main story
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A digital camera that functions like an insect's compound eye is reported in the journal Nature this week.

It comprises an array of 180 small lenses, which, along with their associated electronics, are stretched across a curved mounting.

The prototype currently has few pixels, so its images are low-resolution.

But the device displays an immense depth of field, and a very wide-angle view that avoids the distortion seen in standard camera lenses.

The development team, led from the University of Illinois at Urbana-Champaign, US, believes its new imaging system could eventually find uses in surveillance and for endoscopic investigations of the human body.

In their report, the researchers also suggest such cameras could be fitted to tiny aerial vehicles one day that behaved like robotic insects.

At the moment, the "bug-eye" system's vision is comparable to that enjoyed by some ants and beetles.

The expectation, however, is that the array can be greatly enlarged.

 
Imaging should improve as the number of microlenses is increased "The compound design of the fly's eye incorporates perhaps 28,000 small eyes, or ommatidia," explained team-member Dr Jianliang Xiao from the University of Colorado at Boulder, US. "That's the direction we want to move in," he told BBC News.

In an insect, each ommatidium in the compound eye has a corneal lens, a crystalline cone and a light-sensitive organ at its base. The ommatidia work in unison to build a picture of the world.

In the artificial version, microlenses sit above photodetectors and other electronics, and software stitches together the individual signals.

This whole arrangement is fabricated flat and then moulded to a hemispherical shape to give a 160-degree view. The latest generation of stretchable electronics was key to achieving the desired geometry.

Scientists are keen to exploit the advantages of compound eyes.

For one, they show remarkable depth of field - they can focus on objects at different distances at the same time. They also do not suffer from the aberrations seen in single lens systems when viewing off-axis objects. A good example is the huge distortion observed in wide-angle camera lenses such as the fish-eye.

For an insect, their compound system capabilities make them very sensitive to movement.

"Our system could eventually be used in surveillance cameras. One device of this kind could see 180 degrees. If you had two, you could then conceivably see the whole field of view," said Dr Xiao.

Alexander Borst and Johannes Plett are from the Max-Planck-Institute of Neurobiology in Martinsried, Germany. They are not connected with the research but speculated for Nature on other possible future applications.

"Picture the following: a palm-sized micro aerial vehicle uses an artificial faceted eye to navigate autonomously through a collapsed building while other sensors onboard scan the environment for smoke, radioactivity or even people trapped beneath rubble and debris," they wrote in the journal.