Continuous Capture – The Self-Powered Camera

Renewable energy is growing, with us spotting more and more house sporting solar panels on their roofs to supplement their energy supply. But we are still yet to create the elusive perpetual motion, the hypothetical machine that can run indefinitely without using an outside power source. Of course, scientists don't stop trying to create something because they are told it might be impossible. And they certainly strive to create devices that require as little battery power as possible to run. Which brings us to the Self-Powered Camera, presented to the International Conference on Computational Photography (ICCP) in Texas, on 24 April. Scientists from New York's Columbia University in the US have created a prototype of a video camera that is powered by the light it uses to take a picture. The Self-Powered Camera converts the light that falls on its sensor into electricity, which generates enough energy to take a photo, the light from which is converted into electricity, and... you get the idea. In theory, the device could keep taking pictures forever, or at least until its components corrode! Professor Shree Nayar is the Director of the University's Computer Vision Laboratory, where the camera was invented. He said that we are in the middle of what he calls a "digital image revolution", and there's still much more to come from digital imaging. "[It] is expected to enable many emerging fields," he said. "A camera that can function as an untethered device forever, without any external power supply, would be incredibly useful." Professor Nayar stumbled upon the idea when he realised that solar panels and digital cameras use almost the same component to handle light, something called a photodiode. In solar panels, the photodiodes act like a dam with water, set to "photovoltaic mode". It means they stop the charge of a battery to store up power - like a dam stores up water. Photodiodes in cameras are in "photoconductive mode", so instead of storing power, they pass it along to another part of the camera, like an open dam. By creating a prototype in which the photodiodes alternate between both the capture and the charge mode continuously, the camera sensor can continually take pictures or videos without having any kind of additional power source. The camera is housed in a 3D-printed shell, making it look pretty old-school (left, in the cover photo). However, is is able to take a picture each second and the team was even able to shoot a very short video to demonstrate the camera's abilities. At the moment, the prototype sensor grid is only 30 by 40 pixels in size, with each pixel only using two semiconductors, and the camera is capable of taking very grainy black and white images. Despite that, this is a greatly advanced first step, that could mean a lot for renewable energy and technology design in the future. Professor Nayar explained that there have been different designs in the past for similar image sensors able to harvest energy, but the Self-Powered Camera is the first of its kind. The team's next step is to make a solid-state image sensor with many more pixels, working in the same self-powering way as this prototype. If they are able to accomplish that, then they could potentially produce a standalone camera with a multitude of uses. They claim that the process could even be used to produce power for other devices, such as phones or tablets, when the camera isn't specifically set to capture images. It could function as an inbuilt power generator. However, in its present form, the device isn't yet capable of performing in this manner. There is great potential for this technology to evolve and be adapted for so many things, so let's hope that it catches on quickly! And here's that video we told you about: [video width="600" height="275" id="gDtwn-evLkk" type="youtube"]