Electroactive polymer key to durable, affordable full-screen Braille displays

March 28, 2012

(PhysOrg.com) -- A team of North Carolina State University researchers are one step closer to creating a workable, affordable full-screen Braille computer display that would allow the blind to scan Web pages in much the same way that sighted people do.

The team, composed of textile, electrical and computer engineers, had previously introduced a design that could translate both words and into tactile displays. They wanted to test different materials for use in the actuators, which move the pins that create the Braille dots, to ensure that the raised dots would support the weight of readers’ fingers and enable them to scroll through the material quickly.

Textile engineer Dr. Tushar Ghosh developed an actuator based on silicone tubes, and found that this material resulted in lighter-weight, less expensive devices that still performed as expected.

“Conventional refreshable Braille displays usually incorporate ceramics, or hard materials, in order to do the work of moving the pins up and down to create letters,” says Ghosh. “But they are heavy, difficult to work with and expensive. Electroactive polymer-based silicone tubes are lightweight, flexible, can be processed easily and are inexpensive to manufacture.”

“The result is a device that brings us closer to durable, lightweight and affordable full-screen refreshable Braille displays,” Ghosh says.

The research, which was funded by the U.S. Dept. of Education, appears in Sensors and Actuators A.

The paper was co-authored by NC State electrical and Dr. Paul Franzon, Dr. Neil Di Spigna, Dr. Peichun Yang and graduate students P. Chakraborti, and H.A. Karahan Toprakci.

Explore further: Braille keyboard provides new features

More information: “A Compact Dielectric Elastomer Tubular Actuator for Refreshable Braille Displays”, Authors: P. Chakraborti, H.A. Karahan Toprakci, P. Yang, N. Di Spigna, P. Franzon, T. Ghosh, North Carolina State University, Published: Online in Sensors and Actuators A.

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.

Related Stories

Braille keyboard provides new features

March 11, 2006

Researchers have developed a new Braille computer keyboard with features that are particularly useful for transcribing scientific texts and musical scores.

Snail Braille reader could read books to the blind

May 6, 2011

(PhysOrg.com) -- To most of us, Braille is largely a mystery. It feels really cool, but the idea of actually reading it is kind of a pipe dream. Our sense of touch simply is not as sensitive as that of a blind person. That ...

Here come the quantum dot TVs and wallpaper

December 13, 2011

(PhysOrg.com) -- A British firm's quantum dot technology will be used for flat screen TVs and flexible screens, according to the company’s chief executive.

Recommended for you

Fighting climate change with 'poop power'

December 2, 2015

The stench of clogged toilets fills the air at the US capital's wastewater treatment facility. And for good reason—it's one of the world's largest projects to transform human waste into electricity.

Roboticists learn to teach robots from babies

December 1, 2015

Babies learn about the world by exploring how their bodies move in space, grabbing toys, pushing things off tables and by watching and imitating what adults are doing.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.