E-readers are really starting to come of age with Amazon recently updating and reducing the price of the Kindle. The Nook, Sony Reader, and countless other e-readers are also doing swift business due to the benefits they offer over printed books.The combination of a paper-like screen and thousands of books stored in a very thin, portable device is a tempting offer. Combine that with a battery that can lasts months and you can see why these devices are popular. But there are a couple of areas where paper still wins out: it never needs a recharge and it is flexible.Electronic displays are always going to require power, and you could argue flexibility isn’t that important if the device is very thin and lightweight. Manufacturer AOU is trying to overcome both those problems though, and has this week shown off a flexible piece of e-paper that gets all the power it needs from solar cells.What AOU has managed to do is mount a flexible photovoltaic battery on to the back of a sheet of flexible e-paper. The result is an e-reader that can be rolled up, but also charged without going anywhere near a power socket. That also means it doesn’t require any cables or a plug.As e-paper only requires power when changing what is displayed on the display, the amount of energy required is very low. This prototype unit is 6-inches and has a resolution of 800 x 600. It only requires 218mW of power when refreshing a page. Under (strong) room lighting it’s possible to generate around 130mW, but outside in the sun it’s possible to page refresh without draining the battery at all.The other benefit of e-readers is a full battery can mean a month+ between charges, so you could leave this device lying in the sun for a few hours then use it for a number of weeks before needing to charge it again.AOU hasn’t stated if and when this flexible e-paper will come to market, but it only weighs 10 grams and is 0.127mm thick. If they can ensure the solar charging works well over extended periods, and price it competitively, I can see such a device being very popular. Maybe Amazon could pick it up and use it for the next generation of Kindles.via Tech-On!