近年來隨著生醫產業的蓬勃發展，無論是生物檢測、病原體分析、藥物篩檢、化學合成、食品安檢、環境評鑑，微米粒子的分離或排序都扮演著重要的角色。簡便的分離方式較能進行分析和鑑定，而傳統方法的缺點為，儀器設備昂貴、分析時間冗長、分離步驟繁瑣等都會增加上述流程的難度。相較於其他方式，聲輻射力根據粒子或細胞的大小、密度、壓縮比來進行分離的特性，使其不需要對細胞預先標記或表面改質，可以使細胞在新鮮的狀態下進行分離，且幾乎適合所有種類的微粒。同時，利用表面駐波裝置晶片來控制粒子或細胞移動到壓力節點或反節點，分離和聚焦的過程具有很高的操作性、靈活性和生物相容性。
儘管聲波力擁有許多分離微米粒子上的優點，以往表面駐波晶片都是一次性使用，且晶片製備過程繁瑣、價格昂貴，不具經濟效益，因此本研究目的是讓表面駐波晶片可重複穩定使用，並探討聯結層對粒子聚焦的影響。藉由在微流道和電極晶片之間置入一層聯結層，讓聲波藉由聯結層導入微流道中影響粒子或細胞，我們使用PDMS、水、十二烷作為聯結層的材料，由實驗結果可知使用PDMS時須緊密貼合於壓電材料和微流道裝置之間，才能使聲波導入微流道中，而使用水時在高電壓一段時間下會有揮發或氣泡產生等現象。另外，十二烷具有高沸點、低黏度等特性，可以使聲波在微流道中形成穩定的節點，且能解決使用水所產生的問題，因此使用聯結層的方式可以讓聲波晶片重複再利用，以達到節省成本、增加測試的方便性等目的。

In this study, PDMS film, water, PDMS-water and n-dodecane were used as a coupling layer to contact a reusable disposable SSAW microchips. When using PDMS as a coupling layer, clamping or pressing is needed to ensure PDMS in contact with substrate. When using water or PDMS-water as a coupling layer, bubble generation was observed at high voltage applied(28 Vpp) or longer operation, and stable SSAW could not be formed stably in the channel. When using n-dodecane as a coupling layer, bubble generation was not observed at high voltage applied(41 Vpp) or longer operation(>5 min). The velocity of particle aggregation is close to that when using directly bonded chip. Therefore, using n-dodecane as a coupling layer can make IDT reusable and disposable.

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