E-ink displays, mostly known for their application in ebook readers (ex. Amazon Kindle) are a great way to save power while still being able to enjoy content on fairly large screen. A company called Neoluxiim has decided to go the extra mile and added solar power supply to their e-ink "ink-in-motion" display. They are hoping their device will find its way to advertisers who wish to have large, animated, power-saving screens for pushing their advertising messages – think street displays, airport displays, etc.

The technology is quite simple in its application – take an e-ink screen, add a solar cell to the side, and possibly store excess energy in a small-sized battery to provide power for the display during low-light hours. You'll notice noone mentioned sunlight – that's because the solar cell harnesses light energy emitted from the surrounding lighting systems (street lights, indoor lights). Last but not least, see if you can cram all that in a 7.5 mm thin housing – Neluxiim did it. It's 265 by 165 mm, 7.5 mm thin, has an 18 month continuous usage period. The solar cell is 124 by 39 mm, 2mm thin. Here's what it looks like:

Come to think of it, this concept would probably be quite applicable within our very homes. A small electronic device charger which stores, otherwise lost, light energy from the many light sources in the house. It should be pretty cheap to make micro-solar cells and stick them in the path of light sources around the house, interconnect them, and store generated energy in a battery. Well, off to the local DIY store…