Wouldn’t it be great if you only had to remember to charge your Smarthone once a week, or maybe even once a month? IEEE Fellow Arokia Nathan and colleagues from Cambridge University have made a discovery that might just make such dreams come true.
As Nathan et all describe in their paper published on IEEE Spectrum, they have come up with a way to reuse wasted light that escapes out the sides and back of the typical phone. Instead of it being lost, they use solar cells to capture that light and create energy from it.
Modern Smartphone displays are actually a sandwich, Nathan explains, made up of special type of “gorilla” glass and hidden electronics. The problem with the current design however is that in order to make the display bright enough to read in virtually any environment, a lot gets wasted leaking out the sides or back, where the uses can’t see it. Nathan and his team wondered if it wouldn’t be possible to put tiny little solar cells along the sides and a somewhat larger one in back.
Then, any light that leaks out would find its way to the solar cell where it would be converted to electricity and sent to the phone’s battery, adding to its charge. It’s truly a win-win situation as the more the phone is used, the more light leaks out and the more the solar cell captures it and recharges the battery.
The only down side is that despite the constant battery charging there is still more power being used by the phone than is replenished by the solar cell, which means at some point, the phone will still need recharging. But, thanks to this new research, it might be a week or month before that happens.
Other factors are at work too of course, such as the strength of the processor; the faster it “thinks” the more power it uses. So to do the newer 4G phones which required more powerful hardware to handle the increased network speed.
Also draining juice is the type of display. Those that cover the whole face, such as the iPad, obviously use a lot more than those that are half screen, half keypad.
The new design is still just a proof-of-concept of course, which means that even though it works, users won’t likely see it for at least a year as engineers works out how to incorporate them into existing cell phone lines.