近日,，《自然—通訊》（Nature Communications）期刊上發(fā)表了加拿大麥吉爾大學(xué)生物醫(yī)學(xué)工程系的Mohammad Ameen Qasaimeh和David Juncker與蒙特利爾大學(xué)Ecole Polytechnique分校的Thomas Gervais等學(xué)者的研究成果。他們共同開發(fā)了新型浮動顯微裝置，可用來研究包括腫瘤細胞的形成,、神經(jīng)元如何在大腦發(fā)育中自我調(diào)節(jié)等細胞過程,。
這個新型裝置以四極（quadrupoles）或成對的相同物體為基礎(chǔ),，兩個正極和兩個負極分別安排在正方形的四角,，使它們之間出現(xiàn)一個力場。靜電四極用于無線電天線中,，磁四極則用來集中在粒子加速器中的帶電粒子束,。建造這個裝置要在矽質(zhì)的尖端蝕刻出四個約1平方厘米的小孔。兩個來源孔（正極）會噴出細微的液體,，而另外兩個排水孔（負極）會將液體迅速吸回裝置中,。該裝置的作用類似于吸塵器，能懸浮于活組織切片或者黏附細胞層的表面,，根據(jù)不同的需要,，送出所需的化學(xué)液體來刺激、探測,、分離或殺死細胞。該裝置還能建立化學(xué)濃度梯度變化的區(qū)域,，以研究細菌和其他的細胞如何在體內(nèi)到處活動,，從而應(yīng)用在許多細胞重要過程的體外研究中。(生物谷Bioon.com)
doi:10.1038/ncomms1471
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Microfluidic quadrupole and floating concentration gradient
Mohammad A. Qasaimeh, Thomas Gervais & David Juncker
The concept of fluidic multipoles, in analogy to electrostatics, has long been known as a particular class of solutions of the Navier-Stokes equation in potential flows; however, experimental observations of fluidic multipoles and of their characteristics have not been reported yet. Here we present a two-dimensional microfluidic quadrupole and a theoretical analysis consistent with the experimental observations. The microfluidic quadrupole was formed by simultaneously injecting and aspirating fluids from two pairs of opposing apertures in a narrow gap formed between a microfluidic probe and a substrate. A stagnation point was formed at the centre of the microfluidic quadrupole, and its position could be rapidly adjusted hydrodynamically. Following the injection of a solute through one of the poles, a stationary, tunable, and movable—that is, 'floating'—concentration gradient was formed at the stagnation point. Our results lay the foundation for future combined experimental and theoretical exploration of microfluidic planar multipoles including convective–diffusive phenomena.
