本實驗利用標準微影、蝕刻製程與熔接接合方式製造奈米與微米管道系統。當施加電場於此管道系統中時，由於奈米管道內部電雙層重疊現象，使得奈米管道內部產生離子選擇之特性。而造成奈米管道內正、負離子通量之差異，形成奈米介面處濃度極化之效應。而本文主要包含兩部份：(1)奈米管道幾何對於濃度極化之效應。(2)奈米管道於樣本堆疊之應用。
第一部份，利用奈米管道對於離子之選擇特性，於奈米管道中形成一正離子通量。當施加電壓時，即造成於管道中高電位端產生濃度極化效應，於接地端產生離子聚集效應。濃度極化效應會造成局部離子消耗(depletion)現象，並產生高濃度梯度介面。本論文討論奈米管道長度與寬度對於離子消耗區域之影響。當改變奈米管道長度時消耗區域隨之變化，並且使用電性量測估算消耗區域內部導電率與電場強度。利用電流守恆與歐姆定律，將奈、微米管道系統之3維模組簡化成2維模組，模擬奈、微米介面之初始電場分佈。由模擬可知，當增加奈米管道寬度時，由於電場集中效應過大，導致奈米管道寬度被忽略。
第二部份，利用奈米管道對於離子之選擇特性，因奈米管道中對負離子產生排斥現象，於電場作用下可觀察到消耗區之形成。本論文於管道系統中施予定電壓與偏壓模式，於管道內部分別產生離子累積現象與離子堆疊現象。本論文探討電壓差對於離子累積現象與離子堆疊現象之影響。離子累積現象由於受高電位端所造成電遷移作用與電場增幅區之影響，當增加其高電位端時，同時加強離子累積速度與濃度。離子堆疊現象是由於電壓差所造成電滲作用以及電場增幅區之排斥作用，而造成離子堆疊於其介面。當增加電壓差即增加電滲流之效應，同時增加其離子堆疊濃度。

As the channel dimension scales down to the thickness of the electrical double layer, an inherent ion-permselectivity allows the counterions passing through the nanochannel but repels the coions out of the nanochannel. Under the action of an electrical field, the concentration polarization effect would generate the ionic depletion effect at the anodic side of the nanochannel. In this thesis, the ionic transport within the nanochahnel and the effect of concentration polarization were investigated. The fabrication of the nanochannel was achieved by using the standard photolithography and wet etching technique. The scope of this thesis includes: (1) geometric effect of nanochannel acts on concentration polarization. And (2) applications of nanochannel in microfluidics.
The first part of this thesis, we change the nanochannel length and width to investigate the depletion region. We utilized electrical measurements to estimate the electrical conductivity and the electrical field intensity within the depletion region. Besides, a numerical simulation was conducted to compute the distribution of electrical field as the onset of the depletion effect. Results show the extent of depletion region is sensitive to the length effect, but is insensitive to the width of the nanochannel.
The second part of this thesis, the bias-voltage model combining the ionic depletion effect was utilized to investigate the ion accumulation effect and ion stacking effect in microchannels. The ion accumulation is induced by the difference of the electromigration between the depletion region and non-depletion region. The bias-voltage model is used to generate an extra electroosmotic flow to create an ion convective flux into the stacking region. Results show both of the accumulation and stacking effect were enhanced when the bias was increased.

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