A Tactile Display is a dynamic device which transmits information to blind people by the sense of touch. The stimulation of the human skin can take place in different ways: principally by pressure, vibration or heat. The information can be in the form of images, Braille script and even colours. Braille Displays are a specific class of Tactile Display which can only reproduce Braille symbols.
The scope of the present work is to present a new configuration for actuators in a Braille Display. Shape Memory Alloy wires have been used to raise the single dots of each Braille cell. These actuators can be used in any Braille Display based on pressure stimulation of the fingertips. This kind of wire, when heated, reduces its length by 3% to 4% of its room temperature length. Thanks to this property the dots are raised in a way which will be explained in the present work.
Our guidelines have been to design and develop a low cost Display which could be incorporated in everyday appliances. Furthermore, the low power consumption of the whole system is another important merit factor for its future marketing. The performance constraints such as response time and tactile perception have been satisfied.