Could this be a window to eeeenfinite power? Maybe not quite, but it could be a cool way to extend the lifetime of your smartphone, tablet or e-reader.

A startup called Ubiquitous Energy has been showing prototypes of a translucent film that charges devices with solar energy. The idea is that in the future, the film could be built into device screens, passively juicing your Kindle anytime you read by a sunny window or in the park. It could even keep devices charged during trips to countries for which you don't have the right plugs.