The Strategist

Camera To Click Images Indefinitely Using The Energy Of Light

04/21/2015 - 16:16

Nayar and his team invent a new digital camera that uses the “incidental light” to capture images. Now, no more need of harmful lithium batteries to power cameras, the self-powered camera can continue to click pictures indefinitely.

Columbia – 21 April 2015 – Shree K. Nayar, a professor of Columbia Engineering, who specialises in ‘Computer Science’, along with his research team has “invented a prototype video camera”, the first of its kind” that does not rely on any external source of power. The said video camera is entirely “self- powered”, capable of producing an image every second. This device can continue to click pictures indefinitely if placed under favourable conditions meaning in a “well-lit indoor scene”. The pixels are designed such that they measure “incident light” and convert the same into electricity.
Mr. Nayar, the director of “Computer Vision Laboratory at Columbia Engineering” points out that almost “two billion cameras” of different kinds were sold in the global market. Furthermore, he adds:
"We are in the middle of a digital imaging revolution. I think we have just seen the tip of the iceberg. Digital imaging is expected to enable many emerging fields including wearable devices, sensor networks, smart environments, personalized medicine, and the Internet of Things. A camera that can function as an untethered device forever - without any external power supply - would be incredibly useful."  
Professor Nayar has been conducting leading researches in the field of “computational imaging” wherein he strove to combine the apparently separate devices solar panels and digital cameras. According to him, even though both are designed for separate purposes, there lies a common thread between them, the same constructive component, as “one measures light while the other converts light to power”.
Any digital camera contains “an image sensor” chip within itself which has millions of pixels controlled by photodiodes. The role of the photodiodes is to produce electrical current as and when they are exposed to light. Consequently, each pixel determines the intensity of light to which it was exposed. Interestingly, the same photodiodes convert the sunlight into electricity when used “in solar panels”. The former uses it as a “photoconductive mode”, while the latter as a “photovoltaic model”.
Nayar’s research team consisting of Mikhail Fridberg, a consultant of “ADSP Consulting” and Daniel Sims BS'14, a “research engineer”, fabricated “an image sensor with 30x40 pixels” by using mass produced materials wherein each pixel operates “in the photovoltaic mode”.  The said pixel designs incorporate two simple transistors whereby:
“...the pixels are used first to record and read out the image and then to harvest energy and charge the sensor's power supply”.
BBC reports that the picture quality generated by the self-powered camera has a grainy finish to it. Thus, BBC informs that:
“The camera's creators are now refining the device and are looking into ways to commercialise the technology.”
Moreover, the camera can also generate power to run other electrical gadgets like watches or cell phones. Besides, the image sensors are capable of charging by using rechargeable batteries. Nevertheless, Nayar and his team made sure that the sensors are entirely “self-powered”, thus they introduced a capacitor which is capable of storing just the adequate energy harvested. He says:
"A few different designs for image sensors that can harvest energy have been proposed in the past. However, our prototype is the first demonstration of a fully self-powered video camera."