光電鉗操控液晶微球之研究

Abstract

光電鉗是利用介電泳力來操控微米等級微粒的技術，具有即時的操控性以及能夠同時多點獨立操控的特性，由於其非接觸以及非破壞性的特性，在生醫以及材料科學上遂成為一項值得開發的重要技術。本論文主要是透過光電鉗來操控微米等級之液晶球，並研究在介電泳力與黏滯力兩作用力相互平衡之情況下，液晶球之運動特性。由實驗結果我們發現，介電泳力在 20－100 kHz 的頻率範圍內皆以斥力的形式存在於系統中。在本論文中，我們研究改變交流頻率、外加電場、照光線寬、溶液濃度，及不同液晶球半徑大小等變因下，液晶微球在光電鉗操控下之介電泳力與最大移動速度(速度)之關係。

The optoelectronic tweezers (OET) is a tool to produce an optically controlled dielectrophoretic force by dynamic light patterns on a photo conducting layer. The OET has been developed as a powerful technique in the research of biomedical and material science due to the noncontact and nondestructive properties. In this thesis, we demonstrated, for the first time, the ability of OET to manipulate the liquid crystal (LC) droplets. The influences of the driving frequency, voltage, linewidth of light pattern, radius of the LC droplets and surfactant concentration on the dielectrophoretic force were investigated.