Are you sick of being anxious if your smartphone succeed to stay alive during a very busy day?
The SunPartner Group, a 30-employee startup in Aix-en-Provence, France, is tryring to gine a solution to this common problem. How? They had the idea of taking advantage our little habit leaving our smart phones exposed on the sun and putting a “solar cell” on the them. A similar idea, using solar power in order the phones to be charges also had companies like the Samsung Crest and theSharp Solar Hybrid few years ago. At that time people weren’t inclined to put phones face down on the table—they missed alerts, and were worried about scratching the screen. And solar cells on the back of cell phones never caught on widely. Putting solar cells on the front of a mobile phone is harder, because today phone fronts are virtually all display. Startup Ubiquitous Energy, a spin off from the Massachusetts Institute of Technology, is developing a technology that makes the solar cells themselves transparent by using materials that only absorb infrared and ultraviolet light and let visible light pass through. Researchers at the University of California Los Angeles (UCLA) are taking a similar approach, while researchers at the University of Cambridge are weaving solar cells into organic light emitting diode (OLED) displays, where they can capture light leaked from the edges of the OLED elements as well as from outside the phone.
SunPartner is taking a lower tech approach it believes will get to the mass market much sooner. The company is using stripes of standard thin-film solar cells alternating with transparent film. It then adds a layer of tiny lenses that spread the image coming from the screen to make the opaque stripes disappear as well as to concentrate the rays coming in from the sun. (See illustration, below.)
SunPartner’s Matthieu De Broca says that the company’s current prototypes are 82% transparent while the future versions will reach the percentage of 90%.
The technology will not able to replace the typical way of charging; mobile device users will still plugging their phone in at night. It does, De Broca said, extend the battery life about 20% in normal use. And it can infinitely keep up with the phone’s modest power drain when it is idling in normal daylight. The SunPartner Group, founded by optician Joel Gilbert and businessman Ludovic Deblois, is currently working with three mobile device manufacturers to develop prototypes and expects the first models integrating the technology to be on the market in early 2014. Nokia is reportedly one of those companies.
Photo top: SunPartner’s invisible solar cells with a prototype phone. Credit: Tekla Perry