Barrett Comiskey

An electrophoretic ink for all-printed reflective electronic displays

It has for many years been an ambition of researchers in display media to create a flexible low-cost system that is the electronic analogue of paper. In this context, microparticle-based displays have long intrigued researchers. Switchable contrast in such displays is achieved by the electromigration of highly scattering or absorbing microparticles (in the size range 0.1–5 μm), quite distinct from the molecular-scale properties that govern the behaviour of the more familiar liquid-crystal displays. Microparticle-based displays possess intrinsic bistability, exhibit extremely low power d.c. field addressing and have demonstrated high contrast and reflectivity. These features, combined with a near-lambertian viewing characteristic, result in an ‘ink on paper’ look. But such displays have to date suffered from short lifetimes and difficulty in manufacture. Here we report the synthesis of an electrophoretic ink based on the microencapsulation of an electrophoretic dispersion. The use of a microencapsulated electrophoretic medium solves the lifetime issues and permits the fabrication of a bistable electronic display solely by means of printing. This system may satisfy the practical requirements of electronic paper.

The last book

In this paper we describe our efforts at the Massachusetts Institute of Technology Media Laboratory toward realizing an electronic book comprised of hundreds of electronically addressable display pages printed on real paper substrates. Such pages may be typeset in situ, thus giving such a book the capability to be any book. We outline the technology we are developing to bring this about and describe a number of applications that such a device enables.