Efficient Micro/Nanoparticle Concentration using Direct Current-Induced Thermal Buoyancy Convection for Multiple Liquid Media
Efficient Micro/Nanoparticle Concentration using Direct Current-Induced Thermal Buoyancy Convection for Multiple Liquid Media
复制标题
利用直流电引起的热浮力对流对多种液体介质进行高效的微米/纳米粒子浓缩
DOI：
10.1021/acs.analchem.8b05105
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发表时间：
2019
影响因子：
7.4
通讯作者：
Jiang Hongyuan
中科院分区：
文献类型：
--
作者：
Zhang Kailiang;Ren Yukun;Tao Ye;Liu Weiyu;Jiang Tianyi;Jiang Hongyuan
热聚焦技术由于其无创性和操作机制简单，近年来受到越来越多的关注。然而，目前复杂的流体加热系统和较低的粒子聚焦速度限制了其进一步的应用。利用简单的氧化铟锡微加热器，我们提出了一种基于直流诱导热浮力对流的灵活而新颖的高效粒子聚焦方法。重要的是，为了避免电极上可能发生的电化学反应，微加热器通过薄玻片与感兴趣的颗粒流体隔离。通过静态聚焦4-μm二氧化硅颗粒、酵母细胞、绝缘缓冲液中的二氧化硅颗粒和100 nm铜微球，首次验证了该芯片的浓缩性能。5 μm和2 μm聚苯乙烯微珠的捕获表明，该芯片可以同时集中两种颗粒，也可以通过调节电压选择性地集中较重的颗粒。微球的不同浓度模式表明，微球可以通过改变微加热器的配置来灵活地操纵。此外，我们首次利用浮力对流在导电和绝缘溶液中实现了基于热的连续粒子聚焦，这表明该方法可以用于在多种液体介质中实现静态和连续的粒子操作。最后，通过对液压油中纳米铜颗粒的系统聚焦实验，验证了该装置在机械有效磨损测量中的可行性。因此，这种提出的方法将有望在广泛的片上应用。
Thermal-based microparticle focusing has recently received increasing attention due to its noninvasive nature and simple manipulation mechanism. However, its further application is limited by current complicated fluid heating systems and low particle focusing velocity. Using simple indium tin oxide-made microheaters, herein we propose a flexible and novel approach for efficient particle focusing based on direct current-induced thermal buoyancy convection. Importantly, for avoiding possible electrochemical reactions on the electrode, the microheaters are isolated from the granular fluids of interest by a thin glass slide. The concentration performance of the designed chip was first demonstrated by statically focusing 4-μm silica particles, yeast cells, silica particles in insulating buffer, and 100-nm copper microspheres. Also the trapping of a mixture of 5-μm and 2-μm polystyrene microbeads indicated that the chip can either simultaneously concentrate two kinds of particles or selectively focus the heavier ones by adjusting the voltages. Then the different concentration patterns of microbeads exhibited that the microspheres can be flexibly manipulated by changing the configurations of microheaters. Furthermore, for the first time, we achieved thermal-based continuous particle focusing in both conducting and insulating solutions using buoyancy convection, demonstrating that this method can be utilized to achieve both static and continuous particle manipulations in multiple liquid media. Finally, the feasibility of this device in effective wear measurement of machines was demonstrated by conducting systematic experiments of focusing nanocopper particles in the hydraulic oil. Therefore, this presented approach would be promising for a broad range of on-chip applications.