A refreshable braille cell display uses a single moving part per tactile element. Tactile elements, formed from stainless steel tubing, are assembled in densely arranged modules. Lower ends of the tactile elements extend beneath the modules and are in contact with a pressurized medium. Shape...http://www.google.co.uk/patents/US5685721?utm_source=gb-gplus-sharePatent US5685721 - Refreshable braille-cell display implemented with shape memory alloys
