It’s truly amazing, the wealth of information we all have at
our fingertips — that is, of course, unless your fingertips are
how you have to access that information. An innovative new tablet that
uses magnetically configurable bumps may prove to be a powerful
tool for translating information like maps and other imagery to
a modality more easily accessed by the visually impaired.
The tablet, unnamed as yet, has evolved and improved over the
past few years as part of Europe’s BlindPAD
project, which aims to create a cheap, portable alternative
to touchscreen devices. It’s developed by researchers at the
École polytechnique fédérale de Lausanne.
The latest prototype is about the size of a thick iPad mini,
and it uses a clever mechanism to raise and lower the bumps that
form images, letters or Braille (although they’re rather large
for it). Each little bump is attached to a magnet; the magnet is
always attached to one of two steel layers, and can be switched
by running a current briefly through an adjacent coil. Like an
e-paper screen, no power is required to keep it in its current
position, making it very efficient.
The process is quick enough, though, that the dots can animate
or vibrate for feedback, and could detect being pressed or
glided over by a hand.
The idea isn’t to create a Kindle for the blind, however;
Braille displays must be much higher density. That usually
requires a different type of haptic display,
such as the one used by Blitab. The BlindPAD tablet has 12
rows and 16 columns, for a total of 192 potential bumps,
“taxels” as some have called them. That’s much better suited to
things better shown than described.
“People can read with a Braille display, and detect nearby
obstacles with a white cane,” said EPFL’s Herbert Shea in a news
release. “Our tablet, which will not cost much to produce,
will provide graphic information in real time, so the user can
check out the layout of a room or street before venturing into
It could indicate where safe crossings are on a map of a
corner, tell which of two doorways goes to the appropriate
locker room, or allow a visually impaired student to inspect a
chart or geometry problem in class as easily as their sighted
peers. A study performed last year found
that using the tablet instead of the equivalent in raised dots
on paper had similar benefits for young students.
Our results demonstrate that programmable maps are an
effective way to display graphical contents in
educative/rehabilitative contexts. They can be at least as
effective as traditional paper tests yet providing superior
flexibility and versatility.
BlindPAD’s tablet is still very much in development, but it’s
come a long way since its earlier iterations. The current one
is more efficient, wireless and at least kind of
The technique could also be applied, Shea said, to sighted
people in the form of, for example, gloves that press on the
hand, giving similar spatial information or perhaps tactile
feedback in virtual reality.
The team is showing their latest results at the ACM CHI conference in Denver this