CHEMICAL IMPACT
Electronic Ink
he printed page has been a primary means of communication for over 3000 years, and researchers at the
Massachusetts Institute of Technology (MIT) believe they
have discovered why. It seems that the brain responds positively to fixed images on a sheet of paper, particularly
those areas of the brain that store and process “spatial
maps.” In comparison, information displayed on computer
screens or TV screens seems to lack some of the visual
signals that stimulate the learning centers of the brain to
retain knowledge. While modern technology provides us
with many other media by which we can communicate,
the appeal of written words on a piece of paper remains.
Surprisingly, the technology of printing has changed very
little since the invention of the printing press—that is, until
now.
In the past several years Joseph M. Jacobson and his
students at MIT have developed a prototype of a self-printing
T
page. The key to this self-printing “paper” is microencapsulation technology—the same technology that is used in
“carbonless” carbon paper and “scratch-and-sniff” cologne
and perfume advertisements in magazines. Jacobson’s system involves the use of millions of transparent fluid-filled
capsules containing microscopic particles. These particles
are colored and positively charged on one side and white
and negatively charged on the other. When an electric field
is selectively applied to the capsules, the white side of the
microparticles can be oriented upward or the colored side
can be caused to flip up. Appropriate application of an
electric field can orient the particles in such a way as to
produce words, and once the words have been created,
virtually no more energy is needed to keep the particles in
place. An image can be maintained on a page with consumption of only 50 millionths of an amp of power! The
entire display is about 200 mm thick (2.5 times that of paper)
and is so flexible and durable that it can be curled around a
pencil and can operate at temperatures from 4 to 158°F.
Presently, print resolution is not as good as a modern laser
printer, but reduction of the microencapsulated particles
from 50 to 40 mm should produce print that rivals the quality
of the laser printer.
The first commercial applications of this technology
are expected to appear in retail stores across the country
in the form of electronic signs that can be updated instantly
from a central location. The present technology is a long
way from being able to create electronic books, but this is
the eventual goal of Jacobson’s research team. It seems
very likely that this electronic ink technology will contribute greatly to the evolution of the printed page over the
next century.
Signs like this one created by E Ink are the first to use electronic ink,
which can be updated from a computer inside the store or from a
remote location.