Braille code display device with a PDMS membrane and thermopneumatic actuator

The Braille code display device with a PDMS (polydimethylsiloxane) membrane and thermopneumatic actuator is fabricated and tested. One dot (pixel) whose dimension is 3 mm x 3 mm among six dots in the Braille code is fabricated by using RIE (reactive ion etching), chemical wet etching, and E-beam evaporating. When applied input voltage is under 6 V_PP, the deflections of the membranes occur under the thickness of the silicon substrate. On the other hand, when 8 V_pp and 10 V_pp are applied at 40 mum and 110 mum thickness membranes, the deflections happen about 1 mm, 0.4 mm, 1. 3 mm, and 1.4 mm over the substrate, respectively. The deflection of fabricated device is accomplished over 2 times larger than 600 mum standard height designated by Korea Blind Union.