This is my first post, but here's a fact, the e-ink particles are a janus particle composed of negatively charged black plastic on one side and positively charged white plastic on the other (each bead is thus a dipole) kept between two plates as a matrix, applied voltage aligns the black side or the white side.
The point is there is no screen burn in so its a "screensaver" in name only; as the e-ink is really an electrophoretic display:
http://en.wikipedia.org/wiki/Electronic_paper