Suppose you had a tablet that only displayed one line of text at a time. It would be pretty frustrating, but it's a limitation that blind users of braille-displaying devices are faced with constantly. Thanks to new technology being developed at the University of Michigan, however, full-page refreshable braille tablets could soon be on their way.
In existing devices that have changeable braille displays, the individual dots making up each character are represented by small pins, each one of which is pushed up by an electric motor. Those motors take up some space, so unless the device is going to be huge, only a small number of them can be used – hence the single-line format.
Additionally, because they're so intricate and incorporate so many components, such machines typically cost several thousand dollars. By contrast, it is hoped that the U Michigan technology could result in a tablet costing less than US$1,000.
Led by associate professor Sile O'Modhrain, the team's pneumatic system uses pumped air or liquid instead of motors and pins. Each braille dot takes the form of a tactile bubble that forms beneath the display's rubber surface. For each new page, different combinations of those bubbles are raised to represent different multiple lines of text. As an added benefit, a tablet featuring the new system could also display simple graphics such as charts or tables.
Although the bubbles are fed by tubes in the existing prototype, microfluidic channels would be used in the finished product – similar technology is already utilized in the Phorm iPad mini case, which causes tactile bumps to temporarily form over each letter on the tablet's onscreen keyboard display.
More information is available in the following video. A somewhat similar system is under development at North Carolina State University.