Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang, Malaysia.
Department of Electronic Engineering, Faculty of Engineering, Hadhramout University, Mukalla, Yemen.
Electrophoresis. 2022 Feb;43(3):487-494. doi: 10.1002/elps.202100268. Epub 2021 Nov 5.
The assembly of carbon nanotubes (CNTs) across planner electrodes using dielectrophoresis (DEP) is one of the standard methods used to fabricate CNT-based devices such as sensors. The medium drag velocity caused by electrokinetic phenomena such as electrothermal and electroosmotic might drive CNTs away from the deposition area. This problem becomes critical at large-scale electrode structures due to the high attenuation of the DEP force. Herein, we simulated and experimentally validated a novel DEP setup that uses a top glass cover to minimize the medium drag velocity. The simulation results showed that the drag velocity can be reduced by 2-3 orders of magnitude compared with the basic DEP setup. The simulation also showed that the optimum channel height to result in a significant drag velocity reduction was between 100 μm and 240 μm. We experimentally report, for the first time, the assembly and alignment of CNT bridges across indium tin oxide (ITO) electrodes with spacing up to 125 μm. We also derived an equation to optimize the CNT's concentration in suspensions based on the electrode gap width and channel height. The deposition of long CNTs across ITO electrodes has potential use in transparent electronics and microfluidic systems.
使用介电泳（DEP）在平面电极上组装碳纳米管（CNT）是制造基于 CNT 的器件（如传感器）的标准方法之一。由于 DEP 力的高衰减，电热和电渗等电动现象引起的介质曳力可能会将 CNT 从沉积区域中驱离。在大规模电极结构中，这个问题变得尤为关键。在此，我们模拟并实验验证了一种使用顶部玻璃盖的新型 DEP 装置，以最大程度地降低介质曳力速度。模拟结果表明，与基本的 DEP 装置相比，曳力速度可降低 2-3 个数量级。模拟还表明，要实现显著的曳力速度降低，最佳通道高度在 100μm 到 240μm 之间。我们首次实验报告了 CNT 桥在间距高达 125μm 的氧化铟锡（ITO）电极上的组装和对齐。我们还根据电极间隙宽度和通道高度推导了一个优化悬浮液中 CNT 浓度的方程。长 CNT 在 ITO 电极上的沉积在透明电子学和微流控系统中有潜在的应用。
