介電式液態透鏡與光圈之研究

Studies of dielectric liquid lenses and irises

蔡智偉(Chih-Wei Tsai)

指導教授 ： 葉哲良

國立清華大學/工學院/奈米工程與微系統研究所/博士(2010年)

摘要

The studies in this dissertation focused on developing dielectric liquid lenses and dielectric liquid irises. Their main body composed of two immiscible dielectric liquids with identical densities. When an external electric field passed through the liquid interface, a dielectric force generated deforms the liquid interface to achieve the function of variable focus for a liquid lens and variable aperture for a liquid iris.
A simple force balance model was proposed to derive a experimental equation, which describes the relationship between actuation contact angle and actuation voltage of the dielectric liquid lens. A dynamic equation was constructed to be the foundation of improving the focusing time. Innovative concentric comb electrodes were proposed to lower the actuation voltage and shorten the actuation time.
The measured results of the dielectric liquid lens in this study achieved a great improvement compared to the published results. The experimental dielectric liquid lens shows that the contact angle changed from 7 ° to 63 ° while the effective voltage range is from 4 to 40Vrms. The maximum diopter change was larger than 154 D, as well as the power consumption downed to 0.3 mW.
The study of the dielectric liquid iris proposed is firstly demonstrated in the world. The iris has a capability to continuously vary its aperture with a truly circular shape. The experimental iris had the initial aperture of aperture 4 mm while its aperture shrunk to 1.5 mm under the maximum actuation voltage of 160Vrms and its transmittance in the range of visible light was above 85%.

關鍵字

調變光學元件 ； 液態透鏡 ； 液態光圈 ； 介電力

並列摘要

本研究專注於開發具低耗電量與低驅動電壓的介電式液態透鏡與介電式液態光圈。其基本主體主要是以兩不互溶之等密度介電溶液組成，當外加電場通過兩液體所形成的介面時，由於兩液體具有介電常數差異，因而在介面上產生介電力，本研究即利用介電力作為兩光學調變元件的驅動機制。介電力會調變液態透鏡內之液體介面的形狀以達到調變屈光度的效果，在液態光圈則會調變液體介面的位置以控制光圈大小。
在介電式液態透鏡的研究主要是在於性能提升以及基本理論機制建立。藉由深入了解介電式液態透鏡的驅動機制，作為性能提升的基礎。本論文提出以作用力平衡模型建構出油珠接觸角與驅動電壓的經驗方程式，並且建立介電式液態透鏡的動態方程式以分析其調變時間。藉由理論分析，本論文提出新式的同心指叉式電極以降低驅動電壓以及縮短調變時間。在介電式液態透鏡性能提升研究的具體成果主要有下列幾點：實驗之介電式液態透鏡的直徑為5.0 mm，在接觸角從7°到63°的變化範圍內，其最大驅動電壓範圍為40 Vrms，屈光度變化可達到154D以及最大耗電量在0.3 mW。
本研究之介電式液態光圈是世界首創之調變液態光圈，其特性為具有連續性調變圓形光圈的能力。實驗量測之介電式光圈的起始孔徑為4 mm，在最大驅動電壓為160Vrms的作用下，其孔徑縮小為1.5 mm，孔徑變化率為62%。由於其驅動機制與介電式液態透鏡相同，故耗電量低，其最大耗電量為5 mW，可見光範圍內之光穿透率在85%以上。

並列關鍵字

adaptive optical component ； liquid lens ； liquid iris ； dielectric force

參考文獻

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