使用液態金屬之電濕潤效應製作高對比電控光閥

Fabrication of High Contrast Light Valves Based On Electrowetting of The Liquid Metal

何志銘(Chih-Ming Ho)

指導教授 ： 蔡宗惠

大同大學/電機資訊學院/光電工程研究所/碩士(2009年)

摘要

本論文以電濕潤效應為基礎，使用液態金屬製作高對比之電控光閥為實驗主軸。我們使用的材料為液態金屬“鎵”和透明導電液，取代電濕潤效應之電控光閥中所常用之水和油滴。因液態金屬在透明導電液中且能夠形成水滴般之形態，並施加一電壓後液態金屬受到電壓電流之控制使得展開成薄膜般之形態，其操作模式類似於電濕潤效應。然而液態金屬呈現收縮至水滴形態與玻璃基板之間的接觸角可達到約為130°，並當施加一電壓時液態金屬受到電壓電流之控制呈現展開而似像薄膜般之形態其與玻璃基板之間的接觸角可以達到約為10°以下。液態金屬收縮時，能夠可以使其背光光源穿透，形成明顯為亮(ON)之狀態。然而液態金屬展開時，其金屬之特性可以將背光光源全部反射，形成明顯為暗(OFF)之狀態，因而液態金屬從收縮轉換至展開之形態形成明顯的亮和暗之間的高對比性。由於液態金屬光閥從收縮轉換至展開之間變化可以達到於影像顯示之切換速度，故此一原型有其發展成顯示器之潛力。
經由利用此一現象來製作高對比之電控光閥，並透過液態金屬收縮和展開之形態變化，可以達到高對比至106：1。

關鍵字

液態金屬 ； 接觸角 ； 高對比

並列摘要

Fabrication of high contrast light valve based on electrowetting of liquid metal is demonstrated. We have used gallium which is a liquid metal and transparent conductive solution to replace the water and oil droplet for conventional electrowetting display. Light valve structure consisted of liquid metal (eg. Ga)/transparent conductive solution (eg. H2SO4) was fabricated on an optically transparent substrate. At zero voltage, the initial contact angle of the gallium droplet on interface surface is 130 . When apply a dc voltage, the contact angle of the gallium droplet to the glass substrate can be decreased to as low as 10 with very high reversibility. The liquid metal was extended as the thin film on substrate surface. Operating low voltage is actuated of gallium form retract to expend. The phenomenon lead us to complete a light valve. When the liquid metal retracted, the backlight source provided light transmissions through the light valve module. When the liquid metal is expanded as the thin film, back-light reflected by such a soft metal film. As a result, the high contrast ratio of the formation can be observed. Furthermore, the operation speed of such light valve can achieve to video-speed switching.
We also proceed to minimize the dimensions of the light valve to conventional display pixel size. It shows that such prototype has high contrast ratio.

並列關鍵字

liquid metal ； contact angle ； high contrast ratio

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