Electrostatic trapping of a colloidal monolayer near a charged wall

Sequential plasma processes combined with specific lithographic methods allow for the fabrication of advanced material structures. In the present work, we used self-assembled colloidal monolayers as lithographic structures for the conformation of ordered Si submicrometer pillars by reactive ion etching. We explored different discharge conditions to optimize the Si pillar geometry. Selected structures were further decorated with gold by conventional sputtering, prior to colloidal monolayer lift-off. The resulting structures consist of a gold crown, that is, a cylindrical coating on the edge of the Si pillar and a cavity on top. We analysed the Au structures in terms of electronic properties by using X-ray absorption spectroscopy (XAS) prior to and after post-processing with thermal annealing at 300 °C and/or interaction with a gold etchant solution (KI). The angular dependent analysis of the plasmonic properties was studied with Fourier transformed UV-vis measurements. Certain conditions were selected to perform a surface enhanced Raman spectroscopy (SERS) evaluation of these platforms with two model dyes, prior to confirming the potential interest for a well-resolved analysis of filtered blood plasma.

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Creating a nano-sized light source by electrostatic trapping of nanoparticles in a nanogap

Journal of Micromechanics and Microengineering ◽

10.1088/0960-1317/16/7/023 ◽

2006 ◽

Vol 16 (7) ◽

pp. 1285-1289 ◽

Cited By ~ 10

Author(s):

K Hoshino ◽

K Yamada ◽

K Matsumoto ◽

I Shimoyama

Keyword(s):

Light Source ◽

Electrostatic Trapping

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Development of a polystyrene colloidal monolayer processin the technology of microsphere lithography

Engineering Journal Science and Innovation ◽

10.18698/2308-6033-2020-10-2026 ◽

2020 ◽

Author(s):

E.V. Panfilova ◽

T.H.H. Nguyen ◽

V.A. Dyubanov

Keyword(s):

Colloidal Suspension ◽

Polystyrene Microspheres ◽

Hexagonal Symmetry ◽

Laboratory Equipment ◽

Langmuir Blodgett ◽

Colloidal Films ◽

Atomic Force ◽

Colloidal Monolayer ◽

Regular Arrays ◽

Research Show

The study introduces an operation of deposition of a polystyrene microspheres monolayer from a colloidal suspension, based on the Langmuir ― Blodgett method. The operation plays a key role in the technology of microsphere lithography. The paper describes the laboratory equipment developed to produce ordered colloidal films and monolayers, shows the main modes of the process, and presents the results of studying the surfaces of samples using an atomic force microscope. Findings of research show that the films obtained are close-packed monolayers of microspheres in accordance with the hexagonal symmetry, which are suitable to be used as templates. By means of them and by the method of microsphere lithography, it is possible to obtain regular arrays of nanoparticles of a given size for products of photonics, sensorics, and nanoelectronics.

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Morphology-Controlled 2D Ordered Microstructure Arrays by Surface Modification of Colloidal Template

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.265 ◽

2008 ◽

Vol 8 (9) ◽

pp. 4436-4440 ◽

Cited By ~ 1

Author(s):

Jian-Hong Lee ◽

Ing-Chi Leu ◽

Yi-Wen Chung ◽

Min-Hsiung Hon

Keyword(s):

Surface Characteristics ◽

Two Dimensional ◽

Polystyrene Spheres ◽

Self Assembled Monolayer ◽

Periodic Arrays ◽

Colloidal Monolayer ◽

Surface Modified ◽

Modified Polystyrene ◽

First Time ◽

Structure Patterns

In this paper, we describe a convenient approach for fabricating two-dimensional, ordered TiO2 bowl-like structure and inverted-bowl-like structure patterns consisting of submicrometer arrays on a self-assembled monolayer film, for the first time using a surface-modified polystyrene colloidal monolayer as the template. Typically, the well-ordered two-dimensional TiO2 bowl-like structures were obtained by liquid phase deposition within the interstitial voids in assemblies of polystyrene spheres followed by the dissolution of the polystyrene template with dichloromethane. Otherwise, through a simple wet treatment by immersing in the sulfuric acid at 50 °C, the surface characteristics of polystyrene were turned from hydrophobic to hydrophilic. The ordered inverted-bowl-like structures could be prepared on this treated surface. We believe that this method could be extendable to colloidal template with smaller dimensions, and to periodic arrays made of other materials.

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