Coffee-Ring Effect-Based Three Dimensional Patterning of Micro/Nanoparticle Assembly with a Single Droplet

Abstract

We develop a novel patterning technique to create 3D patterns of micro and nanoparticle assembly via evaporative self-assembly based on the coffee-ring effect of an evaporating suspension. The principle of the technique is analyzed theoretically by the scaling analysis of main parameters of the process and the scaling effect, the effect of the volume, the concentration of the suspension, and the effect of surface treatment on the patterning are studied. On the basis of the presented technique, we demonstrate that the patterns of 3D assembly of various sizes of microparticles (Silica), metal oxide nanoparticles (TiO(2), ZnO), and metallic nanoparticles (Ag) can be successfully generated by low-concentrated particle suspension (1.25-5 wt %) without additional sintering steps, and we also show the geometries of the patterns can be finely controlled by adjusting the parameters of the process.

Numerical simulation of the impact and deposition of charged particulate droplets

“…The approach developed provides a fast computational tool to analyze particulate cluster-droplets. Recently, the author has started a collaboration (see Choi et al [3][4][5] and Demko et al [8]) with an experimental team at UC Berkeley, and the use of the numerical tool to guide the experiments is currently underway The numerical approach and model can be used on virtually any type (shape) of cluster-droplet domain. Since the results are derived from a direct numerical simulation, one can also post-process other more detailed statistical information.…”

“…There are a large variety of industrial deposition techniques, and we refer the reader to the surveys of the state of the art found in Martin [31,32]. Beyond the previously mentioned applications, there are a variety of other areas where cluster of particulates arise, such as small-scale manufacturing processes (see, for example, Luo and Dornfeld [27][28][29][30], Arbelaez et al [1,2], Ciampini et al [6,7], GomesFerreira et al [20], Ghobeity et al [16,17], Choi et al [3][4][5] and Demko et al [8]). Improper handling of these clusters can lead to manufacturing inconsistencies/variability which can strongly affect the overall product quality, in particular if the manufactured devices have small dimensions.…”

“…It is probably more accurate to refer to this as ''resistance to sliding'' at such small scales, however, for brevity, we refer to the effect as ''friction'' 4. They do not move relative to one another.…”

On the thermal response of a surface deposited laser-irradiated powder particle

“…Applications include, for example, optical coatings and photonics (Nakanishi et al [2]), MEMS applications (Fuller et al [3], Samarasinghe et al [4] and Gamota et al [5]) and Biomedical devices (Ahmad et al [6]). In terms of processing techniques, we refer the reader to Sirringhaus et al [7], Wang et al [8], Huang et al [9], Choi et al [10][11][12][13] and Demko et al [14,15] for details. Thus, in order for emerging additive approaches to succeed, one must draw upon rigorous theory and computation to guide and simultaneously develop design rules for upscaling to industrial manufacturing levels.…”

Zigzag-shaped nickel nanowires via organometallic template-free route

“…For instance, coffee ring effect is a well-known drying process which drives particles on the edge of hemispherical droplets, resulting in the formation of circles of particles (Deegan, et al, 1997) (Deegan, 2000). This phenomenon has been observed during the deposition of nanoscale and microscale particles (Choi, et al, 2010). Very interestingly, coffee ring effect could also bring some benefit to deposit connected rings.…”