本研究利用介電泳方式組裝奈米線於微流體晶片內之微電極間隙，首先利用微電極形狀與微流體流速可精準組裝單根或多根奈米線感測器，也設計混成組裝方式形成複合式金屬奈米線與光電半導體奈米線之感測器，並利用局部電場燒結提升感測器性能，最後應用於有機揮發氣體感測。以介電泳方式組裝奈米材料，其優點為不需要繁複的前處理步驟、可在室溫下操縱組裝奈微米材料、只需超微量奈米線溶液，因此在製作和操控上都相當的便利省時；但利用介電泳方式組裝奈米材料，其缺點為準確度較難以控制，因此本研究設計不同微電極結構，探討介電泳奈米線組裝之行為，以達到介電泳奈米線精密組裝，並進一步以電燒結與混成奈米線提升其性能。
在介電泳組裝奈米材料製程上，本研究對於各種介電泳參數做了一系列的探討：奈米材料、溶劑、外加電場頻率、流速、電極形狀，以及利用混成方式輔助奈米線之組裝。在不同的奈米材料與溶劑中，其介電性質與導電度會直接影響介電泳的模式。而在不同的外加電場頻率與流速中，隨著外加電場頻率與流速增加，其奈米線組裝數量會減少，其中在一般式電極當中，電極間距10 μm其組裝的誤差與穩定度比電極間距20 μm來的好。而在手指式電極當中，適當地調整外加電場頻率與流速，可使每個微電極尖端上組裝單一根奈米線，達到介電泳奈米線精密組裝。另外，本論文研究所提出的混成方式輔助奈米線之組裝，可在較大間距微電極下製作出最小達100 nm奈米線間隙之結構，再將短奈米線接於此間隙，可以避免傳統製作奈米電極之昂貴且繁複的電子束微影製程。本研究並進一步探討局部電燒結對降低奈米線間之能障與提升電性之影響。
本論文研究開發之介電泳晶片應用於有機揮發氣體之感測上，由實驗結果可知，在各式介電泳晶片當中，其中以電燒結混成式效果最佳，對於100 ppm濃度下之氨水，室溫下其靈敏度可高達28.02%電阻抗增加率，為一般形式微電極的3.68倍，偵測極限最低可達1 ppm左右，反應時間為60秒，S/N比為14.432。本研究所開發之光電式有機揮發氣體感測器，可以用紫外光來作為控制閘極，提升訊號反應，並當作切換開關以控制有機揮發氣體之感測。此開發之有機揮發氣體感測器未來有潛力應用於疾病呼吸檢測以及環境安全檢測等多方應用。

This paper presents an improved TiO2 based vapor sensor fabricated by dielectrophoretically assembling TiO2 nanowires. Dielectrophoresis (DEP) offers the controllable, selective and massive manipulation of target nanowires. However, it is difficult to achieve precise assembly of nanowires based on dielectrophoresis. In this article we present a novel microelectrode design finger-type electrode to achieve precise assembly of nanowires based on dielectrophoresis.
In this thesis, several important parameters including nanomaterial, solvent, AC frequency, flow rate, and the tip of electrode have been investigated systematically. In different nanomaterial or solution, the induced motion is determined by the dielectric properties and the conductivity of the nanomaterial and solution. And the number of nanowires will reduce with the increase of frequency and flow rate. In the finger-type electrodes, it could be to achieve precise assembly of nanowires based on dielectrophoresis by adjusting appropriately the DEP parameters. Furthermore, compared with the traditional electrode fabrication, electron-beam lithography, there are many the advantages of simple process, low cost, and convenience by using our novel hybrid electrode.
According to experimental results, compared with the traditional nanowire nanosensors, our novel hybrid nanosensors after electrical sintering process exhibited higher sensitivity and lower limit of detection. The sensitivity of our novel hybrid nanosensors is 28.02% under 100 ppm concentration. The limit of detection is 1 ppm. The response time is 120 second. The S/N ratio is 14.432.With the aid of UV light, the sensor exhibits high sensitivity to vapor pollutants including NH3, acetone, and ethanol at room temperature. Our volatile organic compounds (VOCs) nanosensors is of increasing interest for a broad variety of applications in environmental safety monitoring and biomedical breath analysis.

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