本文選題：液滴微流控 + 恒壓驅動　； 參考：《東南大學》2016年碩士論文

【摘要】：液滴微流控是微流控技術的一個重要的分支,對液滴的操控如液滴融合、裂分、混合、分選、捕獲等技術具有非常重要的意義,液滴分選就是從大量液滴中分離出目標液滴,可以用來提純、濃縮目標液滴。微液滴生成和操控的前提條件是穩(wěn)定的流體驅動,流體的驅動方式多種多樣,常用的驅動方式是注射泵,但它有許多固有的缺點,比如分配過程易受溫度變化、膠內(nèi)氣泡、螺桿轉速的影響,而且紋波比較大、單個注射器流量范圍小。氣壓驅動泵比注射泵的紋波小,響應速度快,但是目前市場上的氣壓驅動泵價格昂貴,控制范圍不大。欲實現(xiàn)兼具這些優(yōu)點的氣壓泵,本論文研制了一臺適用于微流控領域的雙氣缸的恒壓微流泵。兩個氣缸的氣壓控制完全獨立,適用于液滴微流控研究。與現(xiàn)有的一些氣壓泵相比,恒壓微流泵的氣壓控制范圍廣、精度較高、氣壓穩(wěn)定、響應速度快。穩(wěn)定時的氣壓波動范圍為±1 mbar,氣壓控制范圍為0.0～10.0 bar。可以用兩款上位機軟件和它進行WiFi通信,用戶可以選擇使用PC機或安卓平板電腦,上位機軟件實時記錄實驗數(shù)據(jù),可以提示各種運行參數(shù),具有友好的交互界面。使用CAD軟件設計了兩種液滴分選芯片,分別利用了壓電陶瓷的逆壓電效應和非均勻電場對液滴的介電泳力,利用恒壓微流泵搭建了液滴分選系統(tǒng)。首先利用搭建的液滴分選系統(tǒng)生成液滴,研究了氣壓為0～240 mbar時液滴直徑、液滴生成速度與油相水相氣壓之比的關系。發(fā)現(xiàn)當油相氣壓值固定時,油相和水相氣壓比值越大,液滴直徑越小,液滴生成速度也越慢;而當油相與水相氣壓比值相同時,油相氣壓越大,液滴直徑越小,液滴生成的速度也越快。利用搭建的液滴分選系統(tǒng),用設計的兩種微流控芯片做了液滴分選�；趬弘娞沾傻姆诌x芯片在氣壓為0～200mbar時給PZT加單個脈沖,改變總持續(xù)時間T和高電平時間Th能夠實現(xiàn)單個液滴分選,目前可以實現(xiàn)11 Hz的液滴流中對單個液滴的分選。然后當油相氣壓為10000 mbar,水相為1000 mbar時生成305 Hz的液滴,對PZT施加連續(xù)的方波,發(fā)現(xiàn)可以分選,且分選率會隨著高電平持續(xù)時間Th增加而增加。基于介電泳的分選芯片在氣壓為0～450 mbar時給金電極施加合適的電壓幅值和頻率,可以把液滴全部拉到目標流道中。且達到全分選時電壓幅值越高頻率就要降低。當電壓過高或者頻率過大時可能使液滴碎裂,故需要選擇好參數(shù)。恒壓微流泵系統(tǒng)適合作為微流控的驅動。基于恒壓微流泵系統(tǒng)的液滴分選是比較基礎的研究,為以后高速微液滴分選打下基礎。
[Abstract]:Droplet microfluidic is an important branch of microfluidic technology. Droplet control, such as droplet fusion, fracturing, mixing, sorting, trapping and so on, is of great significance. Droplet sorting is the separation of target droplets from a large number of droplets. Can be used to purify, concentrate the target droplets. The prerequisite for the formation and control of microdroplets is stable fluid drive, which is often used in injection pumps, but it has many inherent disadvantages, such as the distribution process is susceptible to temperature changes, bubbles in the gel, Screw speed, and the ripple is relatively large, a single syringe flow range is small. The ripple of pneumatic drive pump is smaller than that of injection pump, and the response speed is fast, but the price of pneumatic drive pump is expensive and the control range is not large. In order to realize the pressure pump with these advantages, a double cylinder constant pressure microflow pump suitable for microfluidic control is developed in this paper. The pressure control of the two cylinders is completely independent and suitable for droplet microfluidic research. Compared with some existing air pressure pumps, the constant pressure microflow pump has the advantages of wide air pressure control range, high precision, stable air pressure and fast response speed. The range of pressure fluctuation is 鹵1 mbar. and the control range is 0.010 bar. when the pressure is stable, the range of pressure fluctuation is 鹵1 mbar. Two host computer software and it can be used for WiFi communication, users can choose to use PC or Android tablet computer, PC software records the experimental data in real time, can prompt a variety of operating parameters, with a friendly interactive interface. Two kinds of droplet sorting chips were designed by using CAD software. The inverse piezoelectric effect of piezoelectric ceramics and the dielectric electrophoretic force of non-uniform electric field on the droplet were used respectively, and the liquid drop sorting system was built by using the constant pressure microflow pump. Firstly, the droplet was generated by the designed system, and the relationship between the droplet diameter, droplet formation velocity and the ratio of oil to water pressure was studied when the air pressure was 0 ~ 240 mbar. It is found that the larger the ratio of oil to water pressure is, the smaller the droplet diameter is and the slower the droplet formation rate is when the pressure ratio of oil phase to water phase is fixed, while the larger the pressure ratio of oil phase to water phase is, the smaller the droplet diameter is. The faster the droplets form. Using the designed droplet sorting system and two microfluidic chips designed, the droplet sorting is carried out. A single pulse is added to the chip based on piezoelectric ceramic when the pressure is 0~200mbar. The single drop can be sorted by changing the total duration T and the high level time Th. At present, the single drop can be sorted in the droplet flow of 11 Hz. Then, when the pressure of oil phase is 10000 mbarand the water phase is 1000 mbar, 305Hz droplets are generated, and the continuous square waves are applied to PZTs.It is found that the separation rate increases with the increase of high level duration Th. The separation chip based on dielectric electrophoresis can apply the appropriate voltage amplitude and frequency to the gold electrode at the pressure of 0 ~ 450 mbar, which can pull all the droplets into the target channel. The higher the voltage amplitude is, the lower the frequency will be. When the voltage is too high or the frequency is too high, the droplets may be broken, so we need to select good parameters. The constant pressure microflow pump system is suitable for microfluidic drive. The separation of droplets based on the constant pressure microflow pump system is a relatively basic study, which will lay the foundation for the separation of high speed microdroplets in the future.
【學位授予單位】：東南大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：TN492

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