Two research groups at the University of Tokyo have succeeded a joint development of a braille display sheet using organic transistors. The technology uses organic transistors formed on a flexible substrate to drive actuators made of polymer materials. The research groups claim this is the world's first case that ever succeeds in driving a display using organic transistors and actuators, both formed on a single substrate. The braille display sheet is an electronic board that forms raised letters by projecting and retrojecting the surface using electricity. Unlike the current braille displays using piezo actuators and solenoids, which are several centimeters thick and heavy, this display sheet is as thin as about 1 mm and weighs no more than a few grams.

In addition, the sheet allows users to roll it when carrying, given its flexibility resulted from the use of a polyimide substrate. The research groups aim to commercialize the technology within 4-5 years, expecting applications such as portable electronic books for the blind and IC cards with a service point display.

The prototype uses organic transistors to drive flexible actuators with a hemisphere edge, which push up a silicon rubber sheet on the display surface to form braille letters. A sheet can display 24 letters with 4 rows x 6 lines of picture cells, each of which consists of 3 rows x 2 lines of projections measuring 1 mm in diameter. The display area measures 4 x 4 cm and forms letters at 1 frame per second. When letters are displayed, the height of a projection is about 0.5 mm. Via - Techon