Virtual Braille Dots


Vincent Levesque, Jerome Pasquero and Vincent Hayward


This project was created to investigate the possibility of using the lateral skin stretch technology of the STReSS2 tactile display for Braille. The project was initially conducted at VisuAide inc. and is now being continued in McGill's Haptics Laboratory.

This research project resulted in the VBD device. The prototype consists of an array of 12 piezoelectric benders mounted on a linear slider. The device is used by applying the fingerpad to the tip of the benders and sliding the display laterally. Lateral skin strain patterns are varied based on the position of the display to create the illusion of brushing against Braille dots. This prototype validates the approach for a single row of Braille dots.

vbd_sys.jpg (10111 bytes)

vbd_closeup.jpg (4778 bytes)


The following movie shows activation patterns of the actuators that induce the sensation of virtual Braille dots. When the slider on which the tactile display is mounted scans over a virtual dot, a traveling wave of skin deformation moving in the direction opposite to the slider movement and with the same speed induces the impression that the dot being explored is stationary. If the slider is kept immobile while the activation wave is traveling, one feels the dot moving across the fingertip.