Department of Biomedical Engineering, University of California at Irvine, Irvine, CA 92697, USA.
Lab Chip. 2012 Jan 7;12(1):139-45. doi: 10.1039/c1lc20626e. Epub 2011 Nov 10.
A novel on-chip microfluidic switch is demonstrated that utilizes the acoustic microstreaming generated by an oscillating air-liquid interface to switch cells/particles into bifurcating microchannels. The air-liquid interface of the Lateral Cavity Acoustic Transducers (LCATs) can be actuated by an external acoustic energy source causing the interface to oscillate. The oscillating interface results in the generation of vortex-like microstreaming flow within a localized region of the surrounding liquid. This streaming was utilized here to deflect cells/particles into a collection outlet. It was demonstrated that the switching zone could be controlled by varying the actuation time of the LCAT. An LCAT based microfluidic switch is capable of achieving theoretical switching rates of 800 cells/particles per second. It was also demonstrated that K562 cells could be switched into a collection channel with cell viability comparable to that of controls as determined by Trypan blue exclusion assay.
一种新型的片上微流控开关被展示出来，它利用由振荡气液界面产生的声微流来将细胞/颗粒切换到分叉微通道中。横向腔声换能器（LCATs）的气液界面可以通过外部声能源来驱动，使界面发生振荡。振荡界面导致在周围液体的局部区域产生涡旋状的微流动。这里利用这种流动将细胞/颗粒偏转到收集出口。实验证明，通过改变 LCAT 的激励时间，可以控制开关区。基于 LCAT 的微流控开关能够实现理论上 800 个细胞/颗粒每秒的开关速度。实验还表明，通过台盼蓝排除试验确定，K562 细胞可以切换到收集通道，其细胞活力与对照细胞相当。
