A Portable Pneumatically-Actuated Refreshable Braille Cell

This paper reports a portable pneumatically-actuated refreshable Braille cell. The cell is based on a micromachined, kinematically-stabilized endoskeletal 2 times 3 microbubble actuator array with 1 mm pitch and 1.5 mm diameter. The fabrication process involves SU-8 inclined rotational UV lithography, micromolding, and stereolithography (SLA). The displacement is 0.56 mm and the generated force is 66 mN at 100 kPa applied pressure, respectively. The device has a maximum operating frequency of 200 Hz, suggesting potential uses not only as a Braille display but also for vibratory tactile applications, shape exploration, texture recognition, and other contact sensation-driven applications. The presented fabrication approach is scalable to a full page Braille display.