Lensless Camera Fits on the Head of a Pin

Like a Brownie camera for the digital age, a novel microscopic device developed at Cornell University fits on the head of a pin, contains no lenses or moving parts, costs pennies to make and could revolutionize an array of fields from surgery to robotics.

The camera was invented in the lab of Alyosha Molnar, assistant professor of electrical and computer engineering, and developed by a group led by postdoctoral associate Patrick Gill. Their working prototype is 10 μm thick and 0.5 mm on each side. The camera resolves images about 20 pixels across — not portrait studio quality, but enough to shed light on previously hard-to-see subjects.

“It’s not going to be a camera with which people take family portraits, but there are a lot of applications out there that require just a little bit of dim vision,” Gill said.

The Planar Fourier Capture Array takes images from an array of angle-sensitive pixels. For example, at right, the camera reconstructed an image of the Mona Lisa. (Photo: Molnar lab)

In fact, Gill, whose other research interests involve making sense of how the brain’s neurons fire under certain stimuli, began this invention as a side project related to work on developing lensless implantable systems for imaging brain activity. This type of imaging system could be useful as part of an implantable probe for imaging neurons that have been modified to glow when they are active.

Gill’s camera is just a flat piece of doped silicon, which looks something like a tiny CD, with no parts that require off-chip manufacturing. As a result, it costs just a few cents to make and is incredibly small and light, as opposed to conventional small cameras on chips that $1 or more and require bulky focusing optics.

The scientists call their camera a planar Fourier capture array (PFCA) because it uses the principles of the Fourier transform, a mathematical tool that allows multiple ways of capturing the same information. Each pixel in the PFCA reports one component of the Fourier transform of the image being detected by being sensitive to a unique blend of incident angles.

The work is detailed online in the July 6 issue of Optics Letters.

For more information, visit: www.cornell.edu