Magnetohydrodynamic pumping in nuclear magnetic resonance environments
Magnetohydrodynamic pumping in nuclear magnetic resonance environments
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DOI：
10.1016/j.snb.2006.09.026
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发表时间：
2007-04-10
影响因子：
8.4
通讯作者：
de Rooij, N. F.
中科院分区：
文献类型：
--
作者：
Homsy, A.;Linder, V.;de Rooij, N. F.
我们提出了一个直流磁流体(MHD)泵作为核磁共振微流控芯片的组件。这是第一次在核磁共振环境下观察和演示MHD泵浦。该芯片在7T超导磁体中，在19V的施加电压下产生的最大流量为1.5亩L Min(-1)(微通道中的2.8 mm S(-1))，而功耗仅为38 mW。我们开发了一种简单的方法，通过监测芯片外毛细管中两种不相容液体的液-液界面的位移，来测量体积庞大的核磁共振磁体内的流量。我们将这种流量测量技术与另一种已建立的基于微珠位移的微流控技术进行了比较和验证。这使得我们能够表征和比较永磁体(B(1)=0.33T)和超导磁体(B(0)=7.05T)上的微泵产生的流量。我们观察到与磁场强度之比(B(0)/B(1)=21)相对应的流量增加了21倍，这与理论上流动与磁场强度的关系是一致的。最终目标是将MHD泵和平面线圈集成在一个用于核磁共振分析的微流控系统中。MHD泵在相对较低的流量下的高性能被视为核磁共振和核磁共振应用的一项资产。(C)2006爱思唯尔B.V.保留所有权利。
We present a DC magnetohydrodynamic (MHD) pump as component of a nuclear magnetic resonance (NMR) microfluidic chip. This is the first time that MHD pumping in an NMR environment was observed and demonstrated. This chip generates a maximum flow rate of 1.5 mu L min(-1) (2.8 mm s(-1) in the microchannel) for an applied voltage of 19 V with only 38 mW of power consumption in a 7 T superconductive magnet. We developed a simple method of flow rate measurement inside the bulky NMR magnet by monitoring the displacement of a liquid-liquid interface of two immiscible liquids in an off-chip capillary. We compared and validated this flow measurement technique with another established technique for microfluidics based on the displacement of microbeads. This allowed us to characterize and compare the flow rate generated by the micropump on top of a permanent magnet (B(1) = 0.33 T) with the superconductive magnet (B(0) = 7.05 T). We observed a 21-fold increase in flow rate corresponding to the ratio of the magnetic field intensities (B(0)/B(1) = 21) in accordance with the theoretical flow dependence on the magnetic field intensity. The final aim is to integrate MHD pumps together with planar coils in a microfluidic system for NMR analysis. The high performance of MHD pumps at relatively low flow rates is seen as an asset for NMR and MRI applications. (c) 2006 Elsevier B.V. All rights reserved.