Deterministic Deposition of Nanoparticles with Sub-10 nm Resolution

TL;DR

This paper introduces a nanofluidic-based method for precise nanoparticle placement with sub-10 nm accuracy, combining energy landscapes, electrostatic trapping, and gap reduction for controlled deposition.

Contribution

The authors present a novel geometry-induced energy landscape technique enabling deterministic nanoparticle deposition with nanometer precision, including complex nanostructure assembly.

Findings

Achieved 8 nm placement accuracy for 60 nm gold spheres

Demonstrated versatility with nanorod stacking and nanowire deposition

Validated the method's effectiveness for various nanoparticle types

Abstract

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.