焦耳熱對微流道中電滲影響之初探

On a preliminary investigation of Joule heat effect on electroosmotics in microchannels

李銘哲(Jerry Ming-Che Lee)

指導教授 ： 許文翰

國立臺灣大學/工學院/工程科學及海洋工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.02350

摘要

本論文的研究內容是求解微流體晶片流場之控制方程式，它包含了外加電場之Laplace方程式、壁面電位之Poisson-Boltzmann方程式、不可壓縮之Navier-Stokes方程式、壓力Poisson方程式、能量方程式以及濃度方程式，以便了解焦耳熱效應對微流道中電滲現象的影響。論文係架構在二維正交的座標上，於非交錯網格上壓力與速度耦合配置方式下，採用有限差分方法離散控制方程式，並運用對流－擴散－反應的數值算則，以期準確的求解流體力學以及電滲流相關方程式。

　　由前人研究顯示，若不考慮溫度對流場的影響，則速度曲線不會改變。本研究的主要貢獻，是在固定外加電場強度及緩衝溶液濃度下，改變Zeta電位值（Zeta potential）或電導率強度，進而觀察溫度如何影響流場，並找出在何種狀況下所造成的速度曲線變化為最大，而不可忽略能量方程式。

關鍵字

焦耳熱 ； 生物晶片 ； 微流晶片 ； 電滲流

並列摘要

In order to know the effect of the Joule Heating in micro channels, the governing equations for the microfluidic, including Laplace equation, Poisson-Boltzmann equation, incomepressible Navier-Stokes equations, pressure Poisson equation, energy equation and concentration equation, are numerically simulated by the finite difference method in the non-staggerd two-dimensional grid system. For the sake of accuracy, the convection-diffusion-reaction numerical scheme is employed for all the hydrodynamic and electroosmotic flow equations.

　　If the temperature effect is not taken into account in the flow field, the curve of velocity remains the same. The contribution of this thesis, under the prescribed applied potential and concentration of the electrolyte solution, is to change the Zeta potential or the electrical conductivity for observing the relation between the temperature and fluid fields. Our aim is to know under what conditions we can not neglect the energy equation.

並列關鍵字

Joule heat ； Biochip ； Microfluidic ； Electroosmotic flow ； EOF

參考文獻

[24] 林瑞國, “不可壓縮黏性熱磁流之科學計算方法”, 2005, 博士論文, 國立台灣大學工科海洋所, 36-40, 107-110, 233-240, 259-263

[1] 鍾劍鋒, “設計與模擬微量樣本聚焦/分離/切換蒐集在電驅動微流體系統晶片之應用”, 2004, 碩士論文, 國立成功大學工科所

[2] G. Y. Tang, C. Yang, C. K. Chai, H. Q. Gong, “Numerical analysis of the thermal effect on electroosmotic flow and electrokinetic mass transport in microchannels”, 2004, Analytica Chimica Acta 507, 27-37

[3] G. Y. Tang, D. Yan, C. Yang, H. Q. Gong, J. C. Chai, Y. C. Lam, “Assessment of Joule heating and its effects on electroosmotic flow and electrophoretic transport of solutes in microfluidic channels”, 2005, Electrophoresis, 27, 628-639

[4] G. Y. Tang, C. Yang, H. Q. Gong, J. C. Chai, “Modeling of Electroosmotic Flow and Capillary Electrophoresis with the Joule heating Effect: The Nernst-Planck Equation versus the Boltzmann Distribution”, 2003, Langmuir, 19, 10975-10984