Braille Displays Get New Life With Artificial Muscles
Research with tiny artificial muscles may yield a full-page active
Braille
system that can refresh
automatically and come to life right beneath your fingertips.
Yosi-Bar Cohen, a senior researcher at NASA's Jet Propulsion Laboratory
in
Pasadena, Calif,
was inspired during a business trip to Washington, D.C., where a
convention
for people with
visual impairments was taking place.
Bar-Cohen came up with an idea to create a "living Braille," a digital,
refreshable Braille device
using electroactive polymers, also known as artificial muscles. He wrote
up
a technology report
and included information in a related book that he published. His
writings
inspired other
scientists and engineers to create active displays using this technology,
and prototypes are now
under development around the world.
"I hope that sometime in the future we will have Braille on an iPhone.
It
will be portable and
able to project a picture of a neighborhood popping up in front of you in
the form of raised dots,"
said Bar-Cohen. "A digital Braille operated by artificial muscles could
provide for rapid
information exchange, such as e-mail, text messaging and access to the
web
and other electronic
databases or archives."
According to the World Health Organization, about 314 million people are
visually impaired
worldwide; 45 million of them are blind.
Recently, Bar-Cohen was contacted by the Center for Braille Innovation of
the Boston-based
National Braille Press to reach out to the Electroactive Polymer
community
and take advantage
of his role in this field. The National Braille Press is a non-profit
Braille printing and publishing
house that promotes the literacy of blind children through Braille.
Current Braille Display Technologies
The challenge for creating an active Braille display is in packing many
small dots into a tiny
volume.
Unlike hardcopy Braille, a refreshable display requires the raising and
lowering of a large number
of densely packed dots that allow a person to quickly read them.
Currently,
commercial active
Braille devices are limited to a single line of characters. A full page
of
Braille typically has 25
lines of up to 40 characters per line. Characters are represented by six
or
eight dots per cell,
arranged in two columns. To produce a page of refreshable Braille using
electroactive polymers
requires individually activating and controlling thousands of raiseable
dots.
Developing New Braille Technologies
Some of the leading-edge work in Braille technology was developed at SRI
in
Menlo Park, Calif.
Richard Heydt, a senior research engineer there who was involved in
developing a prototype
says, "The electroactive polymer technology seems to be a natural fit for
Braille and tactile
display applications."
The Braille display developed at SRI is based on activating a type of
polymer consisting of a thin
sheet of acrylic that deforms in response to voltage applied across the
film. The individual Braille
dots are defined by a pattern on this film, and each dot is independently
activated to produce the
dot combinations for Braille letters and numbers.
In currently available active refreshable Braille displays, each dot is a
pin driven by a small motor
or electromagnetic coil. In contrast, in the SRI display the actuators
are
defined regions on a
single sheet of film. Thus, while each dot is raised or lowered by its
own
applied voltage, there
are no motors, bulky actuators, or similar components. Since the system
has
far fewer discrete
components for a Braille dot array, it would be potentially much lower in
cost.
"The contributions of the developers of electroactive materials to making
a
low-cost, active
Braille display would significantly improve the life of many people with
visual impairments,
while advancing the field to benefit other applications" said Bar-Cohen.
Looking for the 'Holy Braille'
The Boston-based National Braille Press has recently established a Center
for Braille Innovation.
They're looking for the "Holy Braille," a full-page electronic Braille
display, at a low cost.
"We feel that the exciting field of electroactive polymer technology has
matured to the point
where it can provide real solutions for Braille displays. We welcome and
encourage anyone who
wants to take part in Braille innovation," said Noel H. Runyan, National
Braille Press, Center for
Braille Innovation
In the spring of 2010, Bar-Cohen is including a special session on
tactile
displays at an SPIE
conference. SPIE is the international society for optics and photonics.
Tactile displays will be
presented and possibly demonstrated at the conference. He hopes these
baby
steps may someday
lead to a full-page Braille system that will allow people to feel and
"see"
the universe beneath
their fingers.
JPL is managed for NASA by the California Institute of Technology in
Pasadena.
