Assistive Technology: Intuitive, High Resolution Tactile Displays for the Visually Impaired

Abstract

Assistive Technology: Intuitive, High Resolution Tactile Displays for the Visually Impaired æXin Xie and Carol Livermore æTactile displays can offer an alternative means of perceiving information for people who are visually impaired. Traditional navigational tools (e.g. canes or assistance animals) are valuable aids to mobility and avoiding obstacles, but there remains a pressing need for technologies that enable the user to acquire graphical information and situational alerts or to navigate in unstructured environments. State of the art tactile displays lack the necessary combination of high resolution and high refresh rate to enable these applications. To address this gap we are creating compact, rapidly-refreshable tactile displays that provide information in an intuitive format as part of a broader system under collaborative development for situational awareness, navigation, and perception of graphical information. Such a device consists of many tactile pixels (ñtactelsî). Each tactel is driven by a piezoelectric extension actuator that expands and contracts in the horizontal direction and is robust under finger pressure. A scissor mechanism on each actuator amplifies the small horizontal oscillations into large vertical oscillations with an amplification factor of up to 40x. The use of high frequency (~250 Hz) actuations increases the usersÍ sensitivity to the signals, and the tactelsÍ inherently high refresh rate enables the coding of information not only as static spatial patterns, but also as easily-recognizable spatio-temporal signals. This poster presents the parametric modeling and design of the tactile array device, along with the experimental implementation of first generation, proof of concept tactels.