Joule heating‐enabled electrothermal enrichment of nanoparticles in insulator‐based dielectrophoretic microdevices
Joule heating‐enabled electrothermal enrichment of nanoparticles in insulator‐based dielectrophoretic microdevices
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DOI：
10.1002/elps.202000192
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发表时间：
2020-09
期刊：
影响因子：
2.9
通讯作者：
Amirreza Malekanfard;Zhijian Liu;Le Song;A. Kale;Cheng Zhang;Liandong Yu;Yongxin Song;X. Xuan
中科院分区：
文献类型：
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作者：
Amirreza Malekanfard;Zhijian Liu;Le Song;A. Kale;Cheng Zhang;Liandong Yu;Yongxin Song;X. Xuan
基于绝缘体的介电泳法(IDEP)利用绝缘结构周围形成的电场梯度来操纵粒子，以满足不同的微流体应用。与传统的电极基介电层析相比，IDEP微器件具有制作简单、不需要水电解、结构坚固等优点。然而，通道内绝缘体的存在可能会因为流体的局部放大焦耳加热而引起热效应。在这项工作中，所产生的电热流循环被用来在基于棘齿的IDEP微器件中捕获和浓缩纳米颗粒(直径小于或等于100 nm)。这种焦耳加热使纳米粒子的电热富集化随着交流电或直流电场的增加而增长。对于较大的颗粒和具有对称棘轮的微通道，它也变得更有效。此外，还开发了一个深度平均的数值模式来理解和模拟各种参数效应，该模式对实验观测结果进行了较好的预测。
Insulator‐based dielectrophoresis (iDEP) exploits the electric field gradients formed around insulating structures to manipulate particles for diverse microfluidic applications. Compared to the traditional electrode‐based dielectrophoresis, iDEP microdevices have the advantages of easy fabrication, free of water electrolysis, and robust structure, etc. However, the presence of in‐channel insulators may cause thermal effects because of the locally amplified Joule heating of the fluid. The resulting electrothermal flow circulations are exploited in this work to trap and concentrate nanoscale particles (of 100 nm diameter and less) in a ratchet‐based iDEP microdevice. Such Joule heating‐enabled electrothermal enrichment of nanoparticles are found to grow with the increase of alternating current or direct current electric field. It also becomes more effective for larger particles and in a microchannel with symmetric ratchets. Moreover, a depth‐averaged numerical model is developed to understand and simulate the various parametric effects, which is found to predict the experimental observations with a good agreement.