Sung Jong Hwan, Shuler Michael L
School of Chemical and Biomolecular Engineering, Cornell University, 115 Weill Hall, Ithaca, NY 14853, USA.
Biomed Microdevices. 2009 Aug;11(4):731-8. doi: 10.1007/s10544-009-9286-8.
Formation of air bubbles is a serious obstacle to a successful operation of a long-term microfluidic systems using cell culture. We developed a microscale bubble trap that can be integrated with a microfluidic device to prevent air bubbles from entering the device. It consists of two PDMS (polydimethyldisiloxane) layers, a top layer providing barriers for blocking bubbles and a bottom layer providing alternative fluidic paths. Rather than relying solely on the buoyancy of air bubbles, bubbles are physically trapped and prevented from entering a microfluidic device. Two different modes of a bubble trap were fabricated, an independent module that is connected to the main microfluidic system by tubes, and a bubble trap integrated with a main system. The bubble trap was tested for the efficiency of bubble capture, and for potential effects a bubble trap may have on fluid flow pattern. The bubble trap was able to efficiently trap air bubbles of up to 10 mul volume, and the presence of captured air bubbles did not cause alterations in the flow pattern. The performance of the bubble trap in a long-term cell culture with medium recirculation was examined by culturing a hepatoma cell line in a microfluidic cell culture device. This bubble trap can be useful for enhancing the consistency of microfluidic perfusion cell culture operation.
气泡的形成是使用细胞培养的长期微流控系统成功运行的严重障碍。我们开发了一种微尺度气泡捕获器，它可以与微流控装置集成，以防止气泡进入该装置。它由两个聚二甲基硅氧烷（PDMS）层组成，顶层提供阻挡气泡的屏障，底层提供替代的流体路径。气泡不是仅依靠其浮力，而是被物理捕获并防止进入微流控装置。制作了两种不同模式的气泡捕获器，一种是通过管子连接到主微流控系统的独立模块，另一种是与主系统集成的气泡捕获器。对气泡捕获器进行了气泡捕获效率测试，以及其对流体流动模式可能产生的潜在影响的测试。该气泡捕获器能够有效捕获体积达10微升的气泡，并且捕获的气泡的存在不会导致流动模式的改变。通过在微流控细胞培养装置中培养肝癌细胞系，研究了气泡捕获器在长期细胞培养和培养基循环中的性能。这种气泡捕获器对于提高微流控灌注细胞培养操作的一致性可能是有用的。
