Carbon nanotubes (CNTs) are promising building blocks for emerging wearable electronics and sensors due to their outstanding electrical and mechanical properties. However, the practical applications of the CNTs face challenges of efficiently and precisely placing them at the desired location with controlled orientation and density. Here, we introduce an electro-fluidic assembly process to assemble highly aligned and densely packed CNTs selectively on a substrate with patterned wetted areas at a high rate. An electric field is applied during the electro-fluidic assembly process, which drives the CNTs close to the patterned regions and shortens the assembly time. Meanwhile, the electric field orientates the CNTs perpendicular to the substrate and anchors one end of the CNTs onto the substrate. When pulling the substrate out of the CNT suspension, the capillary force at the air–water–substrate interface stretches the free end of the CNTs and aligns the CNTs along the pulling direction. By adjusting two governing parameters, the direct current voltage and the pulling speed, we have demonstrated well aligned CNTs assembled in patterns with widths from 1 to 100 μm and lengths from 20 to 120 μm at a rate 20 times higher than a fluidic assembly process. The aligned CNTs show improved electrical conductivity compared with the random networks and prove possibility for strain detection. Precise and reproducible control of the orientation and the placement of the CNTs opens up their practical application in the next-generation electronics and sensors.

中文翻译：

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使用电流体组装工艺组装高度对齐的碳纳米管

碳纳米管（CNT）由于其出色的电气和机械性能，是新兴的可穿戴电子设备和传感器的有前途的构建基块。然而，CNT的实际应用面临有效和精确地将它们以受控的取向和密度放置在所需位置的挑战。在这里，我们介绍了一种电流体组装工艺，可以将高取向和密集堆积的CNT选择性地高速率组装在具有图案化润湿区域的基板上。在电流体组装过程中施加了电场，这驱使CNT靠近图案化区域并缩短了组装时间。同时，电场使CNT垂直于衬底取向并且将CNT的一端锚定到衬底上。将基材从CNT悬浮液中拉出时，空气-水-基质界面处的毛细力会拉伸CNT的自由端，并使CNT沿拉动方向对齐。通过调节直流电压和拉动速度这两个控制参数，我们证明了排列整齐的CNT的图案宽度为1至100μm，长度为20至120μm，其速率比流体组装过程高20倍。与无规网络相比，对齐的CNT显示出更高的电导率，并证明了应变检测的可能性。CNT的方向和位置的精确且可重复的控制打开了它们在下一代电子设备和传感器中的实际应用。通过调节直流电压和拉动速度这两个控制参数，我们证明了排列整齐的CNT的图案宽度为1至100μm，长度为20至120μm，其速率比流体组装过程高20倍。与无规网络相比，对齐的CNT显示出更高的电导率，并证明了应变检测的可能性。CNT的方向和位置的精确且可重复的控制打开了它们在下一代电子设备和传感器中的实际应用。通过调节直流电压和拉动速度这两个控制参数，我们证明了排列整齐的CNT的图案宽度为1至100μm，长度为20至120μm，其速率比流体组装过程高20倍。与无规网络相比，对齐的CNT显示出更高的电导率，并证明了应变检测的可能性。CNT的方向和位置的精确且可重复的控制打开了它们在下一代电子设备和传感器中的实际应用。与无规网络相比，对齐的CNT显示出更高的电导率，并证明了应变检测的可能性。CNT的方向和位置的精确且可重复的控制打开了它们在下一代电子设备和传感器中的实际应用。与无规网络相比，对齐的CNT显示出更高的电导率，并证明了应变检测的可能性。CNT的方向和位置的精确且可重复的控制打开了它们在下一代电子设备和传感器中的实际应用。