A team of researchers plan to create a dynamic electronic surface that lets blind or visually impaired people “feel” graphs, diagrams, and other visuals ordinarily displayed on computer screens. The device is expected to use an electro-active polymer film that can rise slightly and may even wiggle in response to electronic signals, letting users' fingertips sense a pattern. In addition, sound feedback could help users steer their fingers along the lines of a graph or diagram. Although it will take the prototype development about three years before it can convey relatively simple graphics, further advances may someday let blind people use the interface to sense more complex illustrations, including pictures and maps. “In a world that increasingly depends on graphical, pictorial, and multimedia technology, visually impaired and blind people have struggled to keep up,” says team leader Ilona Kretzschmar, assistant professor of chemical engineering at The City College of New York.

Costly instruments to help the blind access the Internet already exist, but they require Braille keyboards and can only process text. “We're trying to make a cheaper device that would receive information tactilely and also be able to receive graphic information,” said Kretzschmar.

The interface is expected to consist of three layers: A bottom layer will be a touch screen connected to a computer for audio feedback to sense the position touched on the screen. The middle layer with embedded electrodes address segments of the polymer top layer. The top is an electro-active polymer film covered with a thin gold film. Segments of the top layer will be able to extend out from the surface as voltage is applied from the corresponding electrode in the middle layer.

Furthermore, Kretzschmar is modifying the polymer film to increase its electro-active properties. The film will then be tested to measure its addressability, maximum elongation, durability, and readability. The team expects guidance from the National Federation of the Blind as to how much the material must change for best tactile detection and a way to receive such information.