Strategy for repetitive pinched injections on a microfluidic device.
Strategy for repetitive pinched injections on a microfluidic device.
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DOI：
10.1021/ac035475y
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发表时间：
2004-09
影响因子：
7.4
通讯作者：
Christopher D. Thomas;S. Jacobson;J. Ramsey
中科院分区：
文献类型：
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作者：
Christopher D. Thomas;S. Jacobson;J. Ramsey
制作了一个具有交叉交叉点和两个近距离三通交叉点的微流体阀，并对重复挤压注射进行了评估。在类似于标准夹紧阀的分析通道中，利用电动势来调动样品并控制交叉路口的扩散输运，从而产生短轴向范围的样品塞。在样品通道中增加一个三通路口，使样品在“回拉”条件下保持靠近注射阀，从而更快地加载到十字路口。第二个三通路口允许在分析通道中单向输送，从而在分析期间加载后续注入。两个三通路口分别位于距离十字路口80微米处。注射频率为1,2.5,5和10hz，占空比为0.5，用于样品加载和分配。配药时给微芯片施加1 kV， 15次注射峰面积的相对标准偏差为1.6%。由于分析通道中存在三通交叉，与标准挤压注射相比，重复注射的峰宽（4sigma）从71微米增加到96微米。
A microfluidic valve was fabricated with a cross intersection and two tee intersections in close proximity and evaluated for repetitive pinched injections. Electrokinetic forces were used to mobilize the sample and control diffusive transport at a cross intersection to produce sample plugs of short axial extent in an analysis channel similar to the standard pinched valve. The addition of a tee intersection in the sample channel maintained the sample close to the injection valve under "pullback"conditions allowing more rapid loading into the cross intersection. A second tee intersection allowed unidirectional transport in the analysis channel enabling loading of subsequent injections during an analysis. The two tee intersections were each located 80 microm from the cross intersection. Injection frequencies of 1, 2.5, 5, and 10 Hz were tested with a duty cycle of 0.5 for sample loading and dispensing. With 1 kV applied to the microchip during dispensing, the relative standard deviation of the peak areas for 15 injections was 1.6%. The peak width (4sigma) for the repetitive injections increased from 71 to 96 microm compared to a standard pinched injection due to the presence of the tee intersection in the analysis channel.