Back in August 2011 E Ink sent me a nice gift - a picture frame with an E Ink "display". It's not really a display as you can't change the image - it's just like a printed photo, using a monochrome E Ink panel. Now it's been over a year since I received the frame, and when I look at it seems the image hasn't changed at all. We all know that E Ink displays are bi-stable - they do not require any energy to show a static display (the picture the frame has no batteries, of course) - but the displays are actually persistent for years.

Persistant framed E Ink display

E Ink says that if the display if sealed and protected properly - it simply will not deteriorate, unless exposed to extreme temperature (a strong magnetic or electric field should not effect the display). In fact, E Ink says that they have a display that was turned off in 2001 - and the image is still visible.

E Ink's electrophoretic e-paper displays are made from tiny micro-capsules that hold black and white particles held in liquid. Applying a charge to the electrodes placed below the capsules repels the white particles to the bottom - and the pixel turns black (a pixel is actually made from a lot's of microcapsules). Changing the color of the pixel can only be done by applying charge to the electrodes - and so once you set the color, it will not change by itself.