| Abstract
| - A wide variety of methods are now available for the synthesis of colloidal particle having controlled shapes,structures, and dimensions. One of the main challenges in the development of devices that utilize micro- and nanoparticlesis still particle placement and integration on surfaces. Required are engineering approaches to control the assemblyof these building blocks at accurate positions and at high yield. Here, we investigate two complementary methodsto create particle assemblies ranging from full layers to sparse arrays of single particles starting from colloidalsuspensions of gold and polystyrene particles. Convective assembly was performed on hydrophilic substrates to createcrystalline mono- or multilayers using the convective flow of nanoparticles induced by the evaporation of solvent atthe three-phase contact line of a solution. On hydrophobic surfaces, capillary assembly was investigated to createsparse arrays and complex three-dimensional structures using capillary forces to trap and organize particles in therecessed regions of a template. In both methods, the hydrodynamic drag exerted on the particle in the suspension playsa key role in the assembly process. We demonstrate for the first time that the velocity and direction of particles inthe suspension can be controlled to perform assembly or disassembly of particles. This is achieved by setting thetemperature of the colloidal suspension above or below the dew point. The influence of other parameters, such assubstrate velocity, wetting properties, and pattern geometry, is also investigated. For the particular case of capillaryassembly, we propose a mechanism that takes into account the relative influences of these parameters on the motionof particles and that describes the influence of temperature on the assembly efficiency.
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