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 3mm x 3mm 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 6Vpp, the deflections of the membranes occur under the thickness of the silicon substrate. On the other hand, when 8Vpp and 10Vpp are applied at 40μm and 110μm thickness membranes, the deflections happen about 1mm, 0.4mm, 1.3mm, and 1.4mm over the substrate, respectively. The deflection of fabricated device is accomplished over 2 times larger than 600μm standard height designated by Korea Blind Union.