A compact dielectric elastomer tubular actuator for refreshable Braille displays

Electroactive polymer actuators stimulated by appropriate levels of electric field are particularly attractive for human-assist devices such as Braille. The development of a full page refreshable Braille display is very important for the integration of the visually impaired into the new era of communication. In this paper, development of a compact dielectric elastomer actuator suitable for Braille application is reported. The actuators are fabricated from commercially available silicone tubes. The tube has been rendered mechanically anisotropic through asymmetric levels of applied pretension in circumferential and axial directions in order to direct the actuation strain in the axial direction of the actuator. Key performance parameters, such as displacement, force, and response time of the actuator are investigated. The test results demonstrate the potential of the compact, lightweight, and low cost dielectric elastomer as actuators for a refreshable full page Braille display.

► We developed an electroactive polymer (EAP) based tubular Braille actuator. ► We produced anisotropic actuation strain by applying directionally different prestrain on the tubular EAP actuator wall through tube inflation and applied axial strain. ► The actuator prototype showed enough displacement to lift the Braille dot the required amount. ► The blocking force was found to be about 0.05 N, which can be potentially improved by using appropriate actuator dimensions.