近年來，生醫科技領域使用3D細胞球體大量應用於醫療檢測、組織工程、再生醫學及腫瘤藥物研究等廣泛領域。其中，以駐表面聲波(Standing Surface acoustic wave, SSAW)結合微流體操控使細胞進行凝聚為最有效率的方式之一，只需不到一天的時間即可形成3D細胞球體，達到球體生成高效率、高通量、高精確度及對細胞活性低傷害等特點。而形成球體方法為在鈮酸鋰(LiNbO3)壓電基板上製作一對指叉狀電極(Interdigital Transducer, IDT)，並施加訊號於電極而產生兩反向表面聲波(Surface acoustic wave, SAW)，兩反向波將相互干涉形成SSAW，使細胞開始匯聚於駐波節點的方式，只需花費1秒即可使細胞聚集，並在1天內成功培育出細胞球體，且細胞球體體積大小均勻。
對於先前研究提出使用表面聲波形成細胞球體的方法，本研究將針對兩個部分進行改善。第一，使用可替換式的細胞培養裝置，讓壓電基板達到重複利用之目的。第二，簡化可替換式細胞培養裝置之製作方式。本研究的目標將結合上述兩特點，達到降低成本、重複使用生醫晶片設置及加速細胞球體生成率之目的。
本研究同步使用COMSOL有限元素模擬分析軟體，來確認可替換式細胞培養裝置生成細胞球體的可行性及效率。透過軟體的靜電、固體力學、層流及粒子追蹤模板進行分析，並使用頻域及時間相依確認可替換式細胞培養裝置之性能。最終，透過模擬結果設計出晶片。晶片製作以半導體微影及蝕刻技術在4吋鈮酸鋰壓電基板上製作指叉狀電極，以微機電技術翻模製作PDMS流道並貼合於蓋玻片上形成可替換式細胞培養裝置，後續使用沸點低且不影響細胞活性的甘油作為訊號傳遞的耦合劑，達到電極重複利用及節省細胞球體實驗設置的製程成本。
實驗結果以多流道的可替換裝置模式，呈現出粒子與細胞排列聚集，實驗結果可形成將近800個粒子或細胞的聚集簇，不僅能夠在1秒內形成聚集簇，亦同時達到高通量及高產量之目的，提升後續細胞球體的生成效率。實驗結果顯示，成功將粒子、MDA-MB-231細胞與Huh-7細胞進行排列聚集，且成功使用MDA-MB-231細胞及Huh-7細胞製作出細胞球體。
本研究實現了在可替換式裝置上進行粒子與細胞操控，並能夠同步在可替換式裝置內成功培育細胞球體。此裝置的特點為首次使用低成本且製程容易的蓋玻片可替換式裝置，展示出粒子與細胞排列並生成細胞球體的技術。而我們同步達成在一片4吋LiNbO3壓電材料上能夠做出兩個培養裝置。

In recent years, 3D cell spheroids have been used in a wide range of fields such as medical testing, tissue engineering, regenerative medicine, and oncology drug research in the field of biomedical technology. Among them, the use of Standing Surface Acoustic Wave (SSAW) combined with microfluidic manipulation of cell coalescence is one of the most efficient ways to form 3D cell spheroids in less than a day. 3D cell spheroids can be formed in less than one day, achieving high efficiency, high throughput, high precision and low damage to cell activity. The spheroids formation method is based on a pair of interdigital transducer (IDT) on a LiNbO3 piezoelectric substrate and applying a signal to the electrodes to generate two inverse Surface acoustic waves (SAW), which interfere with each other to form a SSAW, resulting in the aggregation of cells at the nodes. It takes only 1 second for the cells to gather in the nodes. This method can successfully grow cell spheroids within 1 day and can make cell spheroids of uniform size.
In this study, COMSOL finite element simulation software was used simultaneously to confirm the feasibility and efficiency of the replaceable cell culture device for generating cell spheroids. Electrostatic, solid mechanics, laminar flow, and particle tracking templates were analyzed by the software, and the performance of the alternative cell culture device was confirmed using frequency domain and time dependence. Finally, wafers were designed from the simulation results. IDTs were fabricated on a 4-inch LiNbO3 piezoelectric substrate by semiconductor microfilming and etching, and the PDMS flow channels were molded by microelectromechanical technology and laminated onto cover slides to form the replaceable cell culture device. Glycerol, which has a low boiling point and does not affect the cellular activity, was used as the coupling agent to achieve the goal of reusing electrodes and saving the cost of the experimental setup of cell spheroids.
The experimental results demonstrated the alignment and aggregation of particles and cells in a multi-channel replaceable device mode, which resulted in the formation of clusters of nearly 800 particles or cells, which not only formed clusters within 1 second, but also achieved high throughput and high yield, and enhanced the efficiency of the subsequent generation of cell spheroids. The results showed that the particles, MDA-MB-231 cells and Huh-7 cells were successfully aligned and aggregated, and the cell spheroids were produced using MDA-MB-231 cells and Huh-7 cells.
In this study, we have realized particle and cell manipulation on a convertible device and have successfully grown cell spheroids in the convertible device simultaneously. This device is characterized by the first demonstration of the technology to generate cell spheroids by aligning particles and cells using a low-cost and easy-to-process cover-slip replaceable device. We have also achieved the simultaneous fabrication of two devices on a 4-inch piece of LiNbO3 piezoelectric material.

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