Texture: Refreshable braille display

The idea

Texture is an ebook reader for the visually impaired. It started development as a low cost alternative to the expensive (~2000-4000 USD) refreshable braille displays currently available. The main focus of the project so far has been on the development of cost efective and robust actuators to form the braille dots.

The concept

Texture is being developed with the intention of giving the visually impaired as much freedom to access digital content as we possess.

Hardware

At first, shape memory alloys were chosen because other cost efficiency and ease of manufacture, their drawback being their slow refresh rate (of about 1 second). A few braille cells were developed as prototypes and their performance was found to be unsatisfactory. The nitinol wires  were failing frequently and  not actuating fast enough.

The initial design of the braille dot, with the nitinol wires.

The development was moved to a new concept using piezoelectric discs to vibrate the small braille pins to denote whether it is “on or off”. The current prototypes are more reliable than the nitinol actuators. The  current work has been targeted towards improving the design of the actuator so that the it can be fit into a smaller space.

Alternatively, we are exploring the  viability of using electrical stimulation to make the user perceive the braille dots.

Future work

After the actuator design has been consolidated , work will progress towards developing the entire device and focus will be on the usability and interaction design for the device.

References

New Technology Enables Many-Fold Reduction in the Cost of Refreshable Braille Displays – John Roberts, NIST.