表面聲波式二維多液珠控制平台之研發與應用

當表面聲波遇到液體和固體交界面時，表面波會被轉換成滲漏表面波(Leaky Rayleigh wave)和縱波的形式進入液體內，造成聲射流的現象(acoustic streaming)產生。利用這種現象，將微流體置放在經過疏水處理的基材上，配合交指差電極(IDT)所激發的聲波，當能量大過一定的臨界值時，水珠就會沿著聲波傳遞的方向移動。本論文以兩對斜交指叉式電極(SFIT)所構成的多重微流道系統為基礎，配合比例-積分控制器，同時對系統中不同位置的液珠做定位，期望能提升其實際應用的範圍。本論文結合以128°YX-LibO3為基底之斜交指叉式(SFIT)表面聲波元件和比例-積分控制器來發展一多液珠控制系統。利用斜交指叉式表面聲波元件的偵測功能與比例-積分控制器，可將微液珠控制在大約±100μm的誤差範圍以內。同時，藉由適當的調整比例-積分控制器的參數，液珠移動的速度可以提升且準確度並沒有降低。實驗結果顯示，利用這個系統可以輕易的控制多顆液珠在平台上自行移動與混合。

關鍵字

斜交指叉電極；比例-積分控制器；表面聲波；微流體

並列摘要

Recently, digital microfluidic devices which transport fluid without using a closed channel have attracted increasing attentions in biological applications. This thesis proposes a high-precision digital microfluidic system based on the integration of surface acoustic wave (SAW) technology and a proportional integrated (PI) control algorithm. In this system, we fabricate slanted finger interdigital transducers (SFITs) on a Y128X LiNbO3 substrate to excite and detect SAWs. Then, we employ the PI controller to achieve an accurate manipulation of the microdroplets. Results exhibit high manipulation accuracy and the droplets can be sped up by modulating the control parameters of the PI controller appropriately. Results of this study show the feasibility of using SAW for handling more than one biological process on a single chip and may find possible biological applications.

並列關鍵字

SFIT ； PI control ； SAW ； Digital microfluidic devices

參考文獻

2. S.K. Fan, C. Hashi, C.-J. Kim, “Manipulation of multiple droplets on NxM grid by cross reference EWOD driving scheme and pressure contact packaging”, Proc. Mems, pp. 694-697, 2003

3. Julia C. Chen, Ker-Jer Huang, and J. Andrew Yeh, “Droplet Manipulation on a Hydrophobic Textured Surface With Roughened Patterns”, Journal of microelectromchanical systems, vol. 15, no. 3, June 2006

4. Kunihiro Ichimura, Sang-Keun Oh, Masaru Nakagawa, “Light-Driven Motion of Liquids on a Photoresponsive Surface”, Science 288, 1624, 2000

5. P. Paik, V. K. Pamula, M. G. Pollack, R. B. Fair, “Electrowetting-based droplet mixers for microfluidic systems”, Lab Chip, 3, pp. 28-33, 2003

6. S. Shiokawa, Y. Matsui, T. Ueda, “Liquid Streaming and Droplet Formation Caused by Leaky Rayleigh Waves”, Proc. IEEE Ultra. Symposium, pp. 643 ~646, 1989

國際替代計量

表面聲波式二維多液珠控制平台之研發與應用

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