Display of virtual braille dots by lateral skin deformation: feasibility study

When a progressive wave of localized deformations occurs tangentially on the fingerpad skin, one typically experiences the illusion of a small object sliding on it. This effect was investigated because of its potential application to the display of Braille. A device was constructed that could produce such deformation patterns along a line. Blind subjects' ability to read truncated Braille characters (‘○○’, ‘○•’, ‘•○’, and ‘••’) using the device was experimentally tested and compared to their performance with a conventional Braille medium. While subjects could identify two-character strings with a high rate of success, several factors need to be addressed before a display based on this principle can become practical.