A Dynamic Tactile Interface for Visually Impaired and Blind People.

A team of researchers from five institutions, led by The City College of New York (CCNY), has been awarded $330,000 over three years from the National Science Foundation (NSF) to develop a tactile surface that can facilitate communication between visually impaired and blind persons and computers.

Currently, people who are blind access computers either through screen reading software which speaks the output or expensive Braille displays that can only handle text. “We’re trying to make a cheaper device that would receive information tactilely and also be able to receive graphic information,” said Dr. Ilona Kretzschmar, Assistant Professor of Chemical Engineering at The Grove School of Engineering at CCNY and principal investigator on the grant.

The project is titled “A Dynamic Tactile Interface for Visually Impaired and Blind People.” It proposes to use an electronically addressable and deformable polymeric film to develop the interface device.

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

“In a world that increasingly depends on graphical, pictorial and multimedia technology, visually impaired and blind people have struggled to keep up,” Professor Kretzschmar said. “If we can develop a viable dynamic tactile interface that allows graphic and pictorial information to be presented in real time in tactile rather than visual space, the amount of information available to visually impaired and blind individuals will increase dramatically.”

Professor Kretzschmar is producing Janus particles – particles with two halves and named for the Roman god Janus – to be added to the polymer film to increase its electro-active properties and run mechanical functions. The film will then be tested to measure its addressability, maximum elongation, durability and readability.

Through focus groups with both sighted and blind individuals, researchers expect to obtain feedback on how touch can best convey visual graphic displays, how much the material needs to change for optimal tactile detection and what is the best way to receive the information. Further studies will test tactile interface parameters and fine-tune those parameters for optimal apprehension and interpretability. By the end of the third year, the team expects to have built a prototype dynamic tactile tablet.

Development of a dynamic tactile interface will result in deeper understanding of the touch sense, its relation to vision and sense substitution, the researchers say. The tactile polymer technology could find application in other areas that rely on tactile perception, e.g. sensory materials used in virtual reality, robotics and medical applications.

In addition, it has the potential to be inexpensive and widely applicable to undergraduate engineering student design projects. Some of these could lead to other custom-designed devices for people with physical disabilities.