有鑑於奈米科技的發展潛能，及對未來生活可能產生的影響，因此近年一直是熱門的研究課題。於奈米科技中，流體在奈米尺度下的流動為其中一項研究課題，除了能讓我們有機會探索在奈米尺度下的流動行為以及現象外，更能加以應用在如分離或偵測等許多方面。然而，在製作奈米流道時，不是製程繁瑣，就是所使用之儀器昂貴，因此大多數奈米流體的研究皆以理論分析以及模擬為主。
本研究提出以矽晶圓為基材製作矽微脊結構，並在矽微脊結構上旋轉塗佈PDMS（polydimethyl siloxane），利用PDMS-矽微脊複合結構為模具，灌注PDMS翻製微流道（microchannel），在封閉流道時，藉由施加壓力以得到次微米流道。實驗結果顯示，我們可以運用矽基加工技術（silicon-based micromachining）中的誘導感應偶合電漿離子蝕刻（inductive coupled plasma-reactive ion etching，ICP-RIE），進行一段式或二段式蝕刻以製作矽微脊結構。以一段蝕刻的方式製得的矽脊結構表面較為平滑，但對寬遮罩進行蝕刻時，由於電漿分佈不均，難以準確控制蝕刻時間；而以二段蝕刻的方式，雖然能準確控制蝕刻時間，但得到的矽脊結構表面較粗糙。利用蝕刻所製得的矽微脊長度可達約1 mm。而旋轉塗佈PDMS於矽微脊上所製得的PDMS-矽微脊複合結構，可以用來翻製出低深寬比，截面為三角形之 PDMS微流道。由於PDMS材質強度較弱，可藉由在封裝流道時，因流道塌陷而縮減其尺寸。若在接合過程中再施加壓力，則可以進一步縮減流道尺寸而得到長950 μm、深700 nm、高500 nm之PDMS次微米級流道。

Owing to its potential technology breakthrough to impact the human life, micro/nanotechnology has been heavily pursued in recent years. Study of fluidics at nanoscale is one of the research topics, which not only provides us with the opportunity to better understand the flow behavior at nanoscale and explore new phenomena but also can be used for many applications such as separation, detection, and so on. However, unlike microfluidics, most of the research regarding nanofluidics has been found to relate to theoretical analyses and simulation due to lacking the easy access to nanochannels. In this study, we propose a relatively simple and less expensive alternative to fabricate long sub-micron channels. The microridges are first obtained through inductively coupled plasma- reactive ion etching (ICP-RIE) process, followed by spin-coating and casting of polydimethyl siloxane (PDMS). The results show that both one-step and two-step ICP-RIE processes can be applied to fabricate long microridges. For the one-step process, the surface of the microridges is smooth but the etching time is relatively difficult to control due to the wider mask used. For the two-step process, better control of etching time is possible; however, the surface of the microridges is relatively rough. The length of the microridges can reach up to 1 mm. Spin coating of PDMS on the microridges results in PDMS/microridges composite mold and the lower the spin speed, the lower the aspect ratio of the mold. The triangular shaped PDMS microchannels can be obtained by casting PDMS on the PDMS/microridges composite mold. After bonding, the dimensions of the sealed PDMS microchannels are further reduced because of the collapse of the microchannel edges. With pressure applied during bonding process, fabrication of long sub-micron PDMS channels can be achieved.

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