表面聲波微流體晶片是以聲輻射力作為主要驅動力來操控粒子或細胞的生
物晶片，與傳統聚焦法不同的地方在，粒子不須經過前處理，而可以根據其本
身體積、密度、壓縮比等性質進行聚集排列。此外，其樣品消耗少、可控性高
等優點，已然成為生醫工程領域的熱門研究方向。然而，在使用聚二甲基矽氧
烷(PDMS)與表面聲波駐波(SSAW)組成的微流體晶片中，過往研究對於流道中
壓力節點與壓力反節點的聚焦位置敘述甚少，儘管部分文獻中提出以 1D、2D
模擬預測聚焦結果，仍然存在不少與實驗結果相異之處。
對此，本研究首先以可重複使用之微流體晶片，探討不同聯結層厚度與底
板材質對螢光粒子聚焦速度的影響。接著，使用直接接合式微流體晶片並以改
變流道設計及側壁性質的方式，探討側壁效應對壓力節點分布的影響並嘗試穩
定消除側壁效應。最後，利用不同流道寬度置中對準壓力節點與反節點，對應
兩波長大小不同的雙邊指叉狀電極，探討壓力節點於流道中分布情形，並以
1D-HSW 分析預測節點數量及其成因。
研究結果顯示，可重複使用微流體晶片十二烷連結層厚度對粒子聚焦速度
的自然對數值呈線性衰減，且使用底板材質 PET 相較於玻璃透射聲波能力高出
約為 3.3 倍，但聚焦速度仍不及直接接合式晶片。對於側壁效應的研究，僅透
過區域性的側壁改質以及簡單的流道收縮突擴設計，並無法穩定消除側壁效
應。最後，分析不同流道寬度於 90μm-IDTs、180μm-IDTs 形成壓力節點位置，
以 1D-HSW 理論能夠大致預測其節點數量及分布，且平移流道 1/4 波長距離能
明顯改變流體壓力勢場的分佈。而節點預測失敗之結果，推測為流場內聲波駐
波以一定折角進入流場，同時波長發生改變導致其分布及數量並不如預期。

In SSAW-based microfluidic chips, particles will be trapped at either the pressure
nodes or antinodes depending on the properties of the particles, the fluid, and the
channel wall. For the PDMS-SSAW based microfluidic device, the number of
pressure nodal-lines varied with the microchannel width or acoustic wavelength has
been discussed. In this study, first, utilization of the reusable microchips was
proposed. Then, eliminating sidewall effect by using convergent-divergent channel
design or integrating the metallic block in the channel wall were investigated. Last,
the number of pressure nodal-lines in different microchannels was discussed and the
results were interpreted by 1D-HSW model.

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