A prototype camera that powers itself from the light coming in through the lens has been built by researchers at Columbia University.
Normal cameras work using photodiodes - semiconductors that convert light into current. Photovoltaic cells used in solar panels work in a very similar way, but instead of using the current as information to build a picture, it's collected up and then sent onward. The two processes are similar enough that the Columbia team were able to build a sensor that can alternate between both tasks, and they claim it's the first of its kind.
"A few different designs for image sensors that can harvest energy have been proposed in the past," Shree K. Nayar, the professor who led the team, said in a press release about the project. "However, our prototype is the first demonstration of a fully self-powered video camera."
Here's a sample of the output:
The researchers used off-the-shelf components to build an image sensor measuring 30 x 40 pixels (a paltry 0.0012 megapixels), which they housed in a 3D printed body. When the shutter is pressed, the pixels are first used to record the image in front of them then switched to a mode that harvests energy to charge the sensor's power supply - a small capacity.
That power supply could also theoretically be used to charge a rechargeable battery for a phone or smartwatch.
While the resulting video from the camera isn't too impressive (in fact it's more scary than anything), if the technology is further developed them the applications are huge. CCTV, industrial monitoring, agriculture, wearable technology and other connected devices could all benefit - not to mention the camera industry themselves.
One day, your DSLR might never run out of batteries again.