Tiny lens-free camera takes pixel-perfect pictures

Compiled by BioPhotonics staff

A microscopic device that fits on the head of a pin, contains no lenses or moving parts, and costs just pennies to make could someday revolutionize surgery, robotics and other science applications.

The camera, invented and developed by a group led by Cornell University postdoc Patrick Gill in the lab of Alyosha Molnar, is one-hundredth millimeter thick and one-half millimeter on each side. It resolves images about 20 pixels across. The quality does not compare to that of portraits done in a studio, but it is sufficient to shed light on things previously hard to see.

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

His camera is composed of a flat piece of doped silicon that looks like a tiny CD and contains no parts that require off-chip manufacturing. As a result, the lightweight camera costs mere cents, as opposed to the $1 or more for a conventional small camera on a chip requiring bulky focusing optics.

Dubbed planar Fourier capture array (PFCA), the camera uses the principles of the Fourier transform, a mathematical tool that allows multiple ways of capturing the same information. The sensitivity of each pixel in the PFCA to a unique blend of incident angles allows it to report one component of the Fourier transform of the image detected.

The scientists said they will continue to work on improving the camera’s resolution and efficiency. They believe the concept could be used as a component in cheap electronic systems, such as a device that detects the angle of the sun, or a microrobot that uses a simple visual system for navigation.

The work is detailed online in the July 6 issue of Optics Letters (doi: 10.1364/OL.36.002949).