IBM Research - Zurich , Säumerstrasse 4 , 8803 Rüschlikon , Switzerland.
Nano Lett. 2019 Dec 11;19(12):8855-8861. doi: 10.1021/acs.nanolett.9b03687. Epub 2019 Nov 14.
Accurate deposition of nanoparticles at defined positions on a substrate is still a challenging task, because it requires simultaneously stable long-range transport and attraction to the target site and precise short-range orientation and deposition. Here we present a method based on geometry-induced energy landscapes in a nanofluidic slit for particle manipulation: Brownian motors or electro-osmotic flows are used for particle delivery to the target area. At the target site, electrostatic trapping localizes and orients the particles. Finally, reducing the gap distance of the slit leads sequentially to a focusing of the particle position and a jump into adhesive contact by several nanometers. For 60 nm gold spheres, we obtain a placement accuracy of 8 nm. The versatility of the method is demonstrated further by a stacked assembly of nanorods and the directed deposition of InAs nanowires.
在基板上的特定位置准确沉积纳米颗粒仍然是一项具有挑战性的任务，因为它需要同时实现稳定的长程输运和对目标位置的吸引力，以及精确的短程定向和沉积。在这里，我们提出了一种基于纳米流道中几何诱导的能量景观来进行颗粒操纵的方法：布朗马达或电渗流用于将颗粒输送到目标区域。在目标位置，静电捕获将颗粒定位并定向。最后，减小狭缝的间隙距离会依次导致颗粒位置的聚焦和通过几个纳米的跳跃进入粘附接触。对于 60nm 的金球，我们获得了 8nm 的放置精度。该方法的多功能性通过纳米棒的堆叠组装和 InAs 纳米线的定向沉积进一步得到证明。
