Presenting braille information on two fingers using vibratory patterns from an array of shape-memory alloys

In this study, a wearable Braille display is developed to present Braille information on two fingers (an index finger and a middle finger). We use shape-memory alloy (SMA) wires as an actuator that generates micro-vibration by applying pulse current. Possible vibrating patterns are firstly examined to find the best frequency and timing for presenting Braille information on two fingers. The display has six dots to present one Braille character at one time. For Braille presentation, the actuators in the display are driven by pulse current with the same or different frequencies and different time durations. In addition, to increase recognition rate, we add a button by which a subject starts or restarts Braille presentation. Users' experiments are conducted to verify the ability of the Braille display.