Tiny Display

An e-paper breakthrough brings extremely high-resolution color

- By Simon Makin

VISUAL DISPLAYS HAVE STEADILY gotten smaller and held closer to our eyes as our viewing habits have shifted from cinema screens to TVs to computers, smartphones and virtual reality. This shift has required higher image resolution (usually through increased pixel counts) to provide enough detail. Conventional light-emitting pixels work poorly below a certain size: brightness drops, and colors bleed. The same isn’t true for reflective displays such as those used in many e-readers, whose pixels reflect ambient light rather than emitting their own—but creating those pixels typically requires larger components.

A new reflective display could shatter those restrictions with resolutions beyond the limit of human perception. In a recent study in Nature, scientists describe a reflective retina e-paper that can display color video on screens smaller than two square millimeters across.