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.
credit – Molnar lab
A microscopic device fits on the head of a pin, contains no lenses or moving parts, costs pennies to make — and this Cornell-developed camera could revolutionize an array of science from surgery to robotics.
Their working prototype, detailed online in the journal Optics Letters July 6, is a 100th of a millimeter thick and one-half millimeter 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 things.
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 modified to glow when they are active.
The new 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 cost a dollar 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, which is a mathematical tool that allows multiple ways of capturing the same information. Each pixel in the PFCA reports one component of the so-called Fourier transform of the image being detected by having sensitivity to a unique blend of incident angles. While the Fourier components themselves are sometimes directly useful, a bit of computation can also transform Fourier components into an image.
The scientists will continue working to improve the camera’s resolution and efficiency, and they think their concept can lead to a myriad of applications. It could be a component in any cheap electronic system — in devices that, for example, detect the angle of the sun or a microrobot that requires a simple visual system to navigate.