A touchable tablet developed at École polytechnique fédérale de Lausanne ( EPFL), Switzerland, helps visually impaired users navigate around unfamiliar places. The lightweight, reconfigurable touchscreen tablet generates graphical information that can be ‘read’ with the user’s fingers.
The device incorporates 192 buttons that move up and down in a few milliseconds to create patterns depicting 
Magnetized buttons move up and down to generate shapes. Image credit: EPFLstreet maps or a building’s layout. The actuators are fast enough to make individual buttons vibrate.
Each button contains a tiny magnet placed between two coils and two thin layers of steel. Any given button can be moved up or down by generating a local magnetic field by driving current through one of the coils for five milliseconds. The magnetized buttons then remain in the up or down position because they attach to one of the two steel plates. The 12 x 15 cm tablet is equipped with Bluetooth, so it can connect to computers and tablet PCs.
In addition to navigation, the tablet could also be used to help visually impaired schoolchildren. The researchers say the tablet could be connected to the board to instantly reproduce all the shapes and graphics drawn by a geometry teacher.
