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Digital cameras and solar panels have more in common than you might realize. At their core, both convert light into electric current — it's just that a camera does so to measure light's intensity, and a solar panel does it to create usable power.
A group of Columbia University engineers recently took advantage of this similarity to create something pretty cool: a camera that powers itself.
The camera, which is made from off-the-shelf parts and will be presented next week at the International Conference on Computational Photography, doesn't take especially sharp pictures. Instead, it's intended as a proof of concept:
A short video made from photos taken by the self-powered camera. (Computer Vision Laboratory, Columbia Engineering)
What makes the camera special is its image sensor. Normally, this component senses the intensity of the light hitting the lens with millions of photodiodes — semiconductors that convert light into electric current, which gets encoded as digital data.
But in this camera, the photodiodes cycle back and forth between the image-taking mode and an energy-harvesting mode, in which the current instead charges the battery. This means that if the camera is in a bright area, it can continuously take a photo every second, indefinitely, without ever needing an external charge. The scientists claim it's the first camera that's fully self-powered.
Eventually, this sort of technology could be used in what's called the "Internet of Things": the growing network of ubiquitous wifi-connected devices like smart thermostats, locks, and light bulbs.
A cheap, small camera that can be left on indefinitely could have all sorts of uses. It could perhaps be part of an array of face-recognizing security cameras, for instance, or a series of cameras that sense when someone's in the room to adjust the heating or lighting accordingly.
Read more: Everything's connected — how tiny computers could change the way we live
