| 摘要: | 奈米碳管自1991年被發現後，由於其具許多特殊的性質，特別是在結構的尺度上及電子的傳遞特性，使其成一新興的奈米材料。其它，如高抗拉強度、高熱傳導率及高承受電流強度等，使得奈米碳管在應用的領域上更加寬廣。然而奈米的結構尺度也限制碳管的實際發展，因為目前能夠操作奈米碳管的工具，僅僅只有原子力顯微鏡而已。因此在應用奈米碳管前，要如何克服操作上所遭遇的困難，就成為相當值得研究的課題。 在本文裡，將利用類似生物實驗中，常用來分離不同蛋白質的電泳技術，對不同長度的奈米碳管，進行長度篩選的研究。利用改變電泳實驗中，所施加的外加偏壓類型(直流及交流偏壓)及順序，觀察不同長度的奈米碳管，在實驗中的移動情形，並發現到長度較長的奈米碳管，在實驗中的移動速度要比較短的碳管快。 我們也利用了電泳實驗中，奈米碳管會向電場強度較強的方向 (電極)做移動的特性，將奈米碳管跨接在電極的兩端之間，並以控制電泳實驗中的碳管濃度，改變電極之間的碳管數量。最後，透過量測奈米碳管間的電子傳遞信號，可應用在以奈米碳管製作電子元件方面的研究。在我們的研究中，已成功的由電極兩端，量測到通過碳管的電流訊號，完成以碳管製作氣體偵測器的初步工作。 在以碳管製作場效應電晶體的方面，則是觀察到當閘極偏壓改變時，電晶體的源極與集極之間的電流量(即流經碳管之間的電流)，會受到閘極與源極間電場的影響而有所改變，這也表現出了場效應電晶體的基本工作方式。 上述利用電泳的方式，在操控奈米碳管方面及其相關的運用，顯現出了相當有效的結果，而電泳的實驗裝置與成本則是遠小於其它的操控工具。因此，在操控奈米尺度的材料上，電泳將成為一有效並且方便的工具。 After being found in 1991, the carbon nanotube becomes a rising nanomaterial because of its many special properties, in particular, the dimension of its structure and the conductivity of electrons. Other properties, such as the high tension, heat conductivity, and electric current tolerance broaden the applications of the carbon nanotube. However, the naronic structure limits the advance of the applications of the carbonate nanotube, since so far the atomic force microscope is the only tool to control the carbon nanotube. Therefore, before talking about the applications, to overcome the difficulties in controlling the carbon nanotube is a worthwhile subject. In this thesis, we will use the electrophoresis, which is usually used to separate proteins in biological experiments, to bolt the carbon nanotubes of different length. By changing the bias (with alternative or direct current) applied to the carbon nanotubes and its order, we observe nanotubes of different length and find that the longer nanotubes have higher velocity than those of short length. We impose the character of nanotubes' movement to higher electric field to connect the electrodes with the nanotubes. Then we change the number of tubes between electrodes by tuning the concentration of carbon nanotube in the electrophoresis experiments. Subsequnetly, through measuring the electric signal between nanotubes, the system can be used to design electronic devices. In our work, the electric signal flowed through the nanotubes is detected successfully and the preparing work of producing the gaseous sensor made of nanotubes is done. In the aspect of producing the field effect transistor made of carbon nanotubes, we observe that the change of current between the source and the drain depends on the gate voltage. This implies the fundamental operation of the field effect transistor. The above method using electrophoresis shows sufficient result in controlling the carbon nanotube and the related applications. The cost of the experimental set of electrophoresis is much lower than other manipulative tools, consequently, electrophoresis will be an efficient and convenient technique to control nanomaterials. |
