With the emergence of early microfluidic devices, glass and silicon have been the main substrate material for fabrication. However, the expensive and complicated fabrication procedure constrains the further application. Polymers have become the promising materials under the condition of increasing demand for low-cost microfluidic devices. Polydimethylsiloxane (PDMS) is the most popular material, but PDMS has some limitation. Therefore, thermoplastics might be a good alternative to PDMS for different applications. In this regards, some superior fabrication methods are urgently need to be explored This paper describes a low-cost method for the fabrication four different thermoplastic microfluidic devices including polycarbonate (PC), polymethylmethacrylate (PMMA), polystyrene (PS) and polysulfone (PSU). This process consists of the fabrication of microfluidic features by hot embossing, followed by chloroform vapor assisted thermal bonding. A robust printed circuit board (PCB) served as embossing master is inexpensive and rapid to produce. Beside, PCB master can be used repeatedly over hundreds times without obvious fracture and deformation. The vaporized solvent assisted thermal bonding method allows strong bonded microfluidic devices to fabricate. Importantly, the whole fabrication process takes less than an hour. To demonstrate the performance of this bonding method, dimension loss ratio was also evaluated. In absorption and retention experiments, PMMA displays no absorption and little retention of fluorescent dyes compared to PDMS and PS showed the minimal absorption and retention of nanoparticles. In addition, we perform droplet formation and retention test using this microfabrication method as a demonstration. Among thermoplastic-based microfluidic chips, PC can prevent the water droplets from evaporation. In all, since each dye can be compatible with at least one of the tested substrates and PC can protect droplets against evaporation for long-term experiment, our fabrication method should meet the needs of different applications. Manipulation of droplets in a microfluidic channel has been one of the most important branches of microfluidics. We use this T-junction chip to form uniform droplets. Experiment results show that droplet size can be controlled with changing the flow rate ratio. The larger the flow rate ratio, the smaller the droplets generated. We demonstrate the cells can be successfully encapsulated into the droplet. The number of cells encapsulated in the droplets can be controlled well by adjusting the flow rate of aqueous. Moreover, we can simultaneously manufacture the identical size of droplets with a concentration gradient distribution.

微流控芯片起始於九十年代初期，由於其低樣品量和快速的分析速度等優點而被 廣泛應用于各個領域。如今，微流控芯片不僅能滿足分析化學，生物及其製藥方 面應用的需要，而且逐漸應用於環境監測，臨床診斷和法醫鑑定。早期的微流控 芯片是由硅和玻璃製成的。硅為基質的芯片透光性很差，玻璃的芯片又很易碎。 製作這些芯片不僅需要很專門的製作技術而且還會用到危險的試劑（例如氫氟 酸）。所以昂貴的成本阻礙了他們更為廣泛的應用。隨著這項技術的快速發展， 對簡易及其低成本的芯片的需要越來越迫切。聚合物將是一個很好的選擇。因為 他們有很好的生物兼容性以及光學透明性，無毒而且不易碎。越來越多的聚合物 被用來製做微流控芯片，其中 PDMS 被應用的最為廣泛。雖然 PDMS 有很多優 點，但是他也有相應的侷限性，例如對小分子物質的吸收以及粘附。熱塑性塑料 也是一個可供選擇的材料。可是現在還沒有一個製作方法能製作不同的材料的芯 片。 我們用同一種方法製成四種不同材料的芯片（包括 PMMA,PS,PC 和 PSU）。在 壓片過程中，我們選用了傳統的熱壓法。我們以微電子領域的 PCB 板作為熱壓 的模具。PCB 板不僅便宜而且容易製成，最重要的是它很耐用。在壓制數百片 材料后，它沒有明顯的變形和損壞。在粘接過程中，我們將傳統的熱鍵和方法和 溶劑輔助鍵和的方法相結合，用低溫低壓達到了最後粘接的效果。得到一塊完整 的芯片只需要一個小時。我們還用軌道尺寸的損失比例評價了我們的製作方法。 軌道的寬度和高度的損失比例都在 9％以內，證明了我們製作方法的可行性。同 時我們還選用十二種螢光染料以及一種螢光納米粒子測定四種熱塑性塑料對其 的吸收及其粘附。結果表明只有 PDMS 有明顯的吸收現象，而 PMMA 幾乎與所 有的螢光染料都有很好的兼容性，PS 卻與納米粒子有更好的兼容性。為了證明 我們所製作的以熱塑性塑料為基質的芯片也可以用于一些實際的應用，我們用經 典的“T”結構來製成油包水的液滴。並且觀察記錄了液滴隨時間大小的變化。 結果表明 PC 能夠很好保護液滴不受蒸發的影響。以上實驗結果驗證了我們製作 的四種不同材料芯片能夠被應用于不同的方面。我們還進一步做了相關油包水液滴的實驗。發現可以通過控制油相與水相的速度 來得到不同大小的液滴。當水相是多組分時，我們也可以通過調節不同水相的速 度比（總合保持一致）來得到不同濃度梯度的液滴。最後我們還成功的將 THP-1 懸浮細胞包在液滴內。為其更為廣泛的應用奠定了一定的基礎。 關鍵詞： 熱塑性塑料 製作方法 液滴