Scientists create self-powering camera
By Elly Park
New York, NEW YORK - Scientists at Columbia University in New York have successfully built a camera that is capable of producing images using power harvested from the surrounding incident light.
The prototype self-powering camera takes an image each second, and in a well-lit scene it can operate indefinitely.
The team is led by Shree Nayar, Professor of Computer Science at Columbia Engineering,
"What we have designed here is an image sensor with pixels, with this new design that can not only capture pictures but also generate power from the pixels, in order to capture the images themselves. And that leads us to a fully powered image sensor," Nayar explained to Reuters on Thursday (April 16).
An image sensor is a sensor inside every camera that is responsible for capturing the image. It does so by converting the light information it receives into signals that convey the image. In modern cameras photo diodes, tiny devices inside each pixels of the image sensor, measure the amount of light that falls onto it, and Nayar said he noticed that the process is similar to photo diodes used inside solar panels to harvest energy.
"It turns out exactly the photo diode is also used in solar cells which are used in solar panels to harvest energy from light, except that they are being used in a slightly different circuit. So our thinking was to create, redesign the pixel in the camera so that it can serve both purposes."
In order to build the prototype Nayar worked with research engineer Daniel Sims, and used off-the-shelf components to fabricate an image sensor with 30x40 pixels - the lowest resolution needed for a human face to be recognized.
The pixel design is very simple, and uses two transistors. Continued...