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Tech Times | Bendable camera lenses

Published:Monday | July 18, 2016 | 7:00 AM

Flexible sheet-like lenses could lead to cameras that wrap around your car - or just about anything else.

 

MIT Technology

 

You've probably never seen a camera lens like the one Shree Nayar is working on in his lab at Columbia University. It looks like a clear sheet with a bunch of bumps on it, and unlike, say, the lens inside your smartphone, it's totally flexible. Bending the sheet increases its field of view.

This prototype of a flexible lens array could eventually make it possible to add cameras to all kinds of surfaces: it might wrap around a car to help with autonomous driving or simply provide better visuals while you're backing up, or circle a light pole to take surveillance video in 360 degrees. Nayar also envisions it being combined with a flexible display and built into a thin, flexible camera.

"You could have an entire bumper with this kind of a system - or any surface, for that matter, depending on what the application is," Nayar says.

To get a sense of how this could work, researchers emulated a camera with their bendy prototype. First, they molded a very low-resolution, flexible lens array -just 33 by 33 lenses - in silicone rubber. Then they layered it atop a flexible sheet of plastic with holes in it and a diffusing sheet, and held all these layers in place in a sort of vise that could be used to bend them while a computer monitor projected images from above. While bending all the layers at various angles, the researchers captured the images formed on the diffusing sheet (such as multicoloured dots and a boy with a horse) with a digital camera that they set below the whole contraption.

Nayar thinks this flexible-sheet concept could eventually be used to manufacture a higher-resolution image sensor than what Daniel Sims, a graduate student and lead author of a paper on the subject, was able to make by hand. And he says the researchers are now trying to figure out if deforming the lenses can be helpful for doing things like zooming.

 

MORE PROGRESS

 

He notes, however, that before the technology can become really useful, we'll need to see more progress with other types of flexible electronics and organic sensors that can be printed on various surfaces and aren't based on silicon, unlike traditional image sensors. A fully flexible camera, for instance, would need a flexible display - something that's already been shown off by companies like LG and Samsung but isn't yet available in consumer electronics beyond the occasional curved screen.

John Rogers, a professor at the University of Illinois at Urbana-Champaign whose research includes flexible and stretchable electronics and biologically inspired camera design, agrees. He thinks the researchers did a good job demonstrating the optics, but he says that in a working camera, the lens array would need a flexible high-density, high-pixel-count photo sensor, which isn't yet available.

Still, he says, "I think it's neat work."