Refreshable Braille Display System Driven by Accordion‐Fold Liquid Crystal Elastomer Actuators

Abstract

Refreshable Braille display systems offer dynamic tactile approaches for the blind to obtain text information. However, existing refreshable Braille display systems using soft‐actuator‐driven Braille dots exhibit limitations of small strokes, complex mechanical structures, and high‐driving voltages, which inevitably lead to serious issues in safety, flexibility, and portability. To handle these issues, a novel refreshable Braille display system leveraging accordion‐fold liquid crystal elastomer actuators (AF‐LCEAs) is designed and created, which feature high stroke (1.47 mm), simple mechanical structure, and low driving voltage (20 V). The accordion‐fold structure with a high folding ratio of 59.7% not only enables significantly amplifying actuation strokes, but also brings a compact mechanical architecture for Braille dots. The structured‐LCE‐based refreshable Braille display system can be assembled modularly by multiple display units, which provides the capability to deliver rich and complex tactile information. In addition, a digital electro‐control matrix is designed to enable addressable, programmable electro‐actuation of the multiple LCE Braille dots to enable complicated refreshable tactile patterns. The Braille display system offers a versatile approach to engineering refreshable, portable, small‐sized Braille books useful for the blind.