Directed Assembly (directed + assembly)

Distribution by Scientific Domains


Selected Abstracts


Integration of Density Multiplication in the Formation of Device-Oriented Structures by Directed Assembly of Block Copolymer,Homopolymer Blends

ADVANCED FUNCTIONAL MATERIALS, Issue 8 2010
Guoliang Liu
Abstract Non-regular, device-oriented structures can be directed to assemble on chemically nanopatterned surfaces such that the density of features in the assembled pattern is multiplied by a factor of two or more compared to the chemical pattern. By blending the block copolymers with homopolymers and designing the chemical pattern rationally, complicated structures such as bends, jogs, junctions, terminations, and combined structures are fabricated. Previously, directed assembly of block copolymers has been shown to enhance the resolution of lithographic processes for hexagonal arrays of spots and parallel lines, corresponding to the bulk morphologies of block copolymer systems, but this is the first demonstration of enhanced resolution for more complicated, device-oriented features. This fundamental knowledge broadens the range of technologies that can be served by the directed assembly of block copolymers. [source]


Directed Assembly of Polymer Blends Using Nanopatterned Templates

ADVANCED MATERIALS, Issue 7 2009
Ming Wei
The direct assembly of polymer blends on chemically functionalized surfaces is shown to produce a variety of nonuniform complex patterns. This method provides a powerful tool for easily producing nonuniform patterns in a rapid (30 s), one-step process with high specificity and selectivity for a variety of applications, such as nanolithography, polymeric optoelectronic devices, integrated circuits, and biosensors. [source]


Nanoparticle Inks for Directed Assembly of Three-Dimensional Periodic Structures,

ADVANCED MATERIALS, Issue 19 2003
Q. Li
Colloidal inks, comprised of concentrated barium titanate nanoparticle gels, were directly assembled via a robotically controlled deposition technique. 3D periodic lattices were created through layer-by-layer patterning of parallel rods, whose periodicity far exceeded the dimension of the nanoparticle building blocks. The Figure shows a scanning electron microscopy image of a 3D periodic lattice (top view). [source]


Quartz Binding Peptides as Molecular Linkers towards Fabricating Multifunctional Micropatterned Substrates

ADVANCED MATERIALS, Issue 3 2009
Turgay Kacar
Quartz-binding peptides (QBPs) are used as both ink and linker for microcontact printing and self-assembly, for the co-immobilization of streptavidin-coated quantum dots and fluorescein. Directed assembly of the quantum dots is carried out following microcontact printing of biotinylated QBP1 on a quartz surface. The remaining untouched regions are occupied by the mediated-assembly of fluorescein linked with QBP1. [source]


Directed self-immobilization of alkaline phosphatase on micro-patterned substrates via genetically fused metal-binding peptide

BIOTECHNOLOGY & BIOENGINEERING, Issue 4 2009
Turgay Kacar
Abstract Current biotechnological applications such as biosensors, protein arrays, and microchips require oriented immobilization of enzymes. The characteristics of recognition, self-assembly and ease of genetic manipulation make inorganic binding peptides an ideal molecular tool for site-specific enzyme immobilization. Herein, we demonstrate the utilization of gold binding peptide (GBP1) as a molecular linker genetically fused to alkaline phosphatase (AP) and immobilized on gold substrate. Multiple tandem repeats (n,=,5, 6, 7, 9) of gold binding peptide were fused to N-terminus of AP (nGBP1-AP) and the enzymes were expressed in E. coli cells. The binding and enzymatic activities of the bi-functional fusion constructs were analyzed using quartz crystal microbalance spectroscopy and biochemical assays. Among the multiple-repeat constructs, 5GBP1-AP displayed the best bi-functional activity and, therefore, was chosen for self-immobilization studies. Adsorption and assembly properties of the fusion enzyme, 5GBP1-AP, were studied via surface plasmon resonance spectroscopy and atomic force microscopy. We demonstrated self-immobilization of the bi-functional enzyme on micro-patterned substrates where genetically linked 5GBP1-AP displayed higher enzymatic activity per area compared to that of AP. Our results demonstrate the promising use of inorganic binding peptides as site-specific molecular linkers for oriented enzyme immobilization with retained activity. Directed assembly of proteins on solids using genetically fused specific inorganic-binding peptides has a potential utility in a wide range of biosensing and bioconversion processes. Biotechnol. Bioeng. 2009;103: 696,705. 2009 Wiley Periodicals, Inc. [source]


Facile Fabrication of Monolithic 3D Porous Silica Microstructures and a Microfluidic System Embedded with the Microstructure

ADVANCED FUNCTIONAL MATERIALS, Issue 9 2010
ZuoYi Xiao
Abstract Monolithic 3D porous silica structures are fabricated into a multilayer framework with a bimodal pore size distribution in the micrometer and sub-micrometer range. The fabrication , which involves directed assembly of colloidal spheres, transfer printing, and removal of a sacrificial template , yields robust and mechanically stable structures over a large area. The structure becomes monolithic upon pyrolyzing the stacked layers, which induces necking of the particles. The monolithic microstructures can easily be embedded in microchannels with the aid of photolithography, leading to the formation of a microfluidic system with a built-in microstructure in a site- and shape-controlled manner. Utilization of the system results in a fourfold increase in the mixing efficiency in the microchannel. [source]


Integration of Density Multiplication in the Formation of Device-Oriented Structures by Directed Assembly of Block Copolymer,Homopolymer Blends

ADVANCED FUNCTIONAL MATERIALS, Issue 8 2010
Guoliang Liu
Abstract Non-regular, device-oriented structures can be directed to assemble on chemically nanopatterned surfaces such that the density of features in the assembled pattern is multiplied by a factor of two or more compared to the chemical pattern. By blending the block copolymers with homopolymers and designing the chemical pattern rationally, complicated structures such as bends, jogs, junctions, terminations, and combined structures are fabricated. Previously, directed assembly of block copolymers has been shown to enhance the resolution of lithographic processes for hexagonal arrays of spots and parallel lines, corresponding to the bulk morphologies of block copolymer systems, but this is the first demonstration of enhanced resolution for more complicated, device-oriented features. This fundamental knowledge broadens the range of technologies that can be served by the directed assembly of block copolymers. [source]


Micropatterning: Quartz Binding Peptides as Molecular Linkers towards Fabricating Multifunctional Micropatterned Substrates (Adv. Mater.

ADVANCED MATERIALS, Issue 3 2009
3/2009)
The cover shows a fluorescent microscopy image of co-assembly of streptavidin functionalized quantum dots (SA-QD) and fluorescein molecules self-assembled using biotinylated and conjugated quartz binding peptides (QBP-bio and QBP-fluorescein). Mehmet Sarikaya and co-workers describe how inorganic binding peptides can act as universal linkers on p. 295. Stamping of the QBP-bio using micro-contact printing is followed by directed assembly of SA-QD (red). The QBP-fluorescein is then immobilized on the bare silica (green) to generate uniform bifunctional micropatterns. [source]