Mechanism Design for Improved Resolution in Refreshable Tactile Graphics

Tactile perception is a medium that enables the blind to read text and diagrams. The available books are bulky and at times, expensive. Refreshable Braille Displays are commercially available devices that display one line at a time but a medium for reading diagrams remains absent from the market. Such a device would require thousands of independently actuated dots that need to be packed in a constrained area. Even if such scale is achieved, it comes with high costs and power consumption. Technologies have been developed that use small arrays of actuators but those are limited to reading braille text. The ability to identify and read diagrams remains essential for the blind to grasp knowledge and pursue their interests. A cost efficient and reliable device could empower the visually impaired and provide the advantages that auditory aids never could. This report discusses the choice and design of different actuators so as to develop graphics that offer a better resolution through a decrease in the dot to dot distance compared to existing devices, along with a cost-efficient mechanism. It finally discusses the design of a braille cell using a bimetallic actuator which offers improved resolution.