在微粒子表面進行塗層或是表面改質，常常使用在醫藥科學、毒性檢測、化學與工程學當中。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需要對粒子本身進行一些前處理或是針對不同的粒子需要不同的流道設計，而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)的方式，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層或是表面改質，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單一流道內進行橫向移動，以及找出最適合的操作參數，並嘗試在PS粒子表面塗層PAH帶正電高分子。初步的結果顯示，對於未修飾過的粒子，不同的帶電高分子濃度會影響電性的表現，但滯留時間的長短影響電性最為顯著；另外對於有修飾過的粒子，由於本身官能基的影響，在濃度不同以及滯留時間長短的影響下，電性測試的結果都比未修飾過粒子來的高且穩定。

In this study, surface acoustic wave microchips were used to perform conformal coating of microparticles. The reusable chips were constructed where the PDMS channel was bonded to the thin glass slide and n-dodecane was used as a coupling layer between the glass slide and the lithium niobate substrate. The results showed that, for the fluorescent PS particles, the electric charge of the outer layer was affected by the concentration of the coating solution, and the residence time of the particles in the coating solution. It was also found that the residence time plays an important role in determining the electric charge. For the carboxylate conjugated particles, the zeta potential of the coated particles and their stability were higher than the coated fluorescent PS particles.

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