Tiny, lens-free camera developed for scientific use
By Ben Coxworth
July 6, 2011
It fits on the head of a pin, has no lens or moving parts, can be made for just a few cents, and yet it can take a photo of the Mona Lisa in which she's actually sort of recognizable ... it's called the Planar Fourier Capture Array (PFCA), and it's a tiny camera developed at New York's Cornell University. Although you might choose not to use it for photographing your child's birthday party, it could come in quite handy in the fields of science and technology.
The PFCA was developed by a group led by postdoctoral associate Patrick Gill, in the lab of Alyosha Molnar, Cornell assistant professor of electrical and computer engineering.
It's basically just a flat piece of doped silicon, containing no parts that require off-chip manufacturing. This allows it to stay very small, measuring one-hundredth of a millimeter thick, and a half-millimeter on each side. It can also be produced at a cost of just a few cents. Miniature cameras that are manufactured separately from the chips upon which they're mounted, on the other hand, are larger and cost about a dollar a piece to produce.
The PFCA takes its name from the Fourier transform, a mathematical tool in which the same information can be captured in different ways. When capturing an image, each of its pixels reports one component of the image being detected, by being sensitive to that image's unique blend of incident angles. A computer then combines these different components into one image.
Pictures produced by the camera are only about 20 pixels across - pretty low resolution, but enough for certain applications. Implanted in a test subject's brain, for instance, it could image neurons that have been modified to glow when active. It could also be used in electronic devices that measure the angle of the Sun, in miniature robots that require a simple navigational vision system, or in various other capacities.
The Cornell team is now working on improving its resolution and efficiency.
"To me, the most exciting aspect of our invention is that this is the first camera that doesn't use mirrors, lenses, or moving parts," Gill told us. "This is a new class of camera that challenges the ideas of what we've always thought a camera had to be."