在醫藥科學、化學與工程學當中，常常在微粒子表面進行塗佈或是表面改質。而目前微流體塗層或是表面改質的技術大多利用磁力或是或是慣性力讓粒子穿越多層的化學物質。利用磁力或是流體力學的方式往往對於粒子本身會有一些前處理或是對於不同的粒子需要不同的流道設計，這些前處理可能會破壞某些粒子特性，若通入粒子為細胞，這些處理可能直接殺死細胞。因此我們研發一個方式，利用單邊指叉狀(interdigital transducer, IDT)電極在壓電材料上產生表面聲波(surface acoustic wave , SAW)，讓聲波傳遞至流道內並且推動粒子橫跨多層流道，利用聲波的特性就不須對於粒子或細胞進行預先標記或是表面處理，也不會對微粒子有任何的汙染，可以使細胞在新鮮的狀態下進行表面塗佈或是表面改質，這樣的方法幾乎適用於所有微粒子。
本研究旨在探討如何利用聲波晶片使粒子在彎曲流道內進行橫向移動，以及找出最適合的操作區間，並嘗試在PS粒子表面塗佈PAH與PSS等兩種帶電高分子。由實驗可知，聲波力會因為流道距離IDT越遠而遞減，在使用聯結層的情況下，最靠近IDT的流道(第一流道)內的粒子受到聲波力最強，次靠近IDT的流道(第二流道)內的粒子受到聲波所產生的peripheral streaming作用明顯，其餘流道內粒子受力隨流道與IDT距離的增加而遞減。粒子在經過多層流後表面電位因帶電高分子的層塗而改變，確實達成了粒子的表面層塗。

In this study, the serpentine, surface acoustic wave microchips were used to perform conformal coating of microparticles. The reusable chip was used where the PDMS channel was bonded to the thin glass and n-dodecane was used as a coupling layer to contact a lithium niobate substrate. The results showed that the particles can move across the channel after applying SAW. Accumulation of particles along the channel wall was observed at high voltage applied (40VPP). The particles were not able to move across the channel when low voltage was applied (<30VPP). Using reusable chip with the serpentine channel design, the particles can be coated with polyelectrolyte.

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