生物微粒之電性阻抗量測及區別技術

Electrical Characteristic Measurements and Discrimination of Bioparticles by Electrorotation and Impedance Measurement Method.

指導教授 : 黃榮堂    研究生 : 林佳慶   製造科技研究所 92年


摘要

 此篇論文是運用微機電(MEMS)技術,製做出可量測微小的細胞微粒之介電係數及導電度的量測晶片,以提供各生物細胞或是菌類的量測機制。此實驗主要是利用介電泳對於細胞所產生之電泳效應,來對細胞做一個非接觸式的量測。

在本論文的實驗中,將有條理的利用Electrorotation(Rot)逐步對細胞、細菌的介電係數及導電度量測做一系列的實驗,其中首先要瞭解電泳、介電泳的基本原理,電極形狀設計以及透過模擬軟體分析出電場的分佈狀況。在實驗的步驟中(1)利用氯化鉀(KCL)與去離子水調配出不同導電度的介質溶液,並找出最適合的溶液,對生物微粒做操控及吸附(Trapping)的實驗 (2)建構生物微粒的模型(model):將生物微粒建構出一單殼模型(Single shell model)(3)生物微粒的性質改變:利用加熱或是病毒的感染,來改變操縱變因,正常與感染之間的比較(4)生物微粒的衰亡:量測出粒子活性的變化反映在特性曲線上的趨勢。

在實驗的結果中,本研究成功地利用純物理的量測方式,量測出微粒之間的微小差異性,脫離了傳統化學檢測方式,不需花費時間等待化驗結果;另外也成功利用電泳的方式操控粒子的移動並加收集。當粒子的特性量測得知後,就可以依據微粒之間微小的差異,利用電場加以分離純化,對於物理性的整合檢測晶片提供了關鍵的數據。對於未來的發展,以純物理的微機電技術,來製作微電極、微流道,並以介電泳與電泳效應對於介電細胞進行操控,是本研究最終實現檢測晶片的目標。檢測晶片以低成本的材料生產製作,可以快速且有效率檢驗出結果,也是本研究與傳統化學檢測有所區別的優勢所在。

關鍵詞:微機電(MEMS)技術、介電泳、電泳、Electrorotation(Rot)、誘導偶極矩(Dipole moment)、檢測晶片

ABSTRACT

 In this thesis, a novel microelectrode chip for Bio-particle’s permittivity and conductivity measurement is manufactured by MEMS technique. Using this chip, we can measure the electrical characteristic of cells and bacteria through employing DEP effect with un-contact method.

Experiments are implemented by using ROT method to measure permittivity and conductivity of a series of cells and bacteria progressively. In the beginning, it is to realize the principle of EP and DEP, design the shape of electrode and simulate the electric field distribution. Then, several main steps of the experiments are implemented:(1)Different conductivity of medium: Use KCL to obtain different conductivity medium, then drive and measure bio-particle to get different result. In this way, we can obtain different critical point with different medium conductivity and range of positive and negative DEP effect. (2) The property change of Bio-particle: Change the operation factor by heating or infecting particles by virus, then compare with normal ones. (3) Declination of bio-particle: Measure the activity change of bio-particle and its tendency response on the characteristic curve of ROT.

In the result of experiment, we measure the small difference of particle by physical method successfully instead of the traditional chemical method, so that it can save time to wait making a chemical assay. In addition, using DEP force can move and collect bio-particles. Base on the small difference of characteristic among bio-particles, it can use electric field effect to separate and purify them. Furthermore itcan provide important data for integrated Bio-chip. In the feature, because of employing MEMS technology to fabricate micro-electrode and micro-channel, a pure “physical” biochip may be achieved through manipulating the bio-particle by DEP or EP force and measuring their electrical properties. Since Biochip is low cost and high efficiency, it may be more advantageous than chemical assay.

Keywords:Microelectrode, MEMS, dielectrophoresis, DEP,Electrorotation(Rot), Electrophoresis, Lab-on-a-chip, Dipole moment