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Microcontact Printing (microcontact + printing)
Selected AbstractsImproved Microcontact Printing of Proteins using Hydrophilic Thermoplastic Elastomers as Stamp Materials,ADVANCED ENGINEERING MATERIALS, Issue 12 2007C. Trimbach Recently, the microstructuring of biological species, such as proteins, using microcontact printing (,CP), has become very popular. Microstructuring of proteins is useful for a variety of applications, such as biosensors, controlled cell growth and adhesion and microarrays for bioanalytical detection. Here the authors investigated the microcontact printing of proteins using a hydrophilic thermoplastic elastomeric stamp material. The emphasis is placed on the quality of the printed patterns with respect to inking time and protein concentration in the ink. [source] Nanopatterning by an Integrated Process Combining Capillary Force Lithography and Microcontact PrintingADVANCED FUNCTIONAL MATERIALS, Issue 4 2010Xuexin Duan Abstract A novel nanopatterning process was developed by combining capillary force lithography (CFL) and microcontact printing (µCP). Flat polydimethylsiloxane (PDMS) was used as the substrate in CFL, and after chemical functionalization, as the stamp in µCP, which increased the resolution of both methods. The polymer patterns, produced by CFL on a thin polymer film on the flat PDMS substrate, acted as a mask to oxidize the uncovered regions of the PDMS. The chemical patterns were subsequently formed by gas phase evaporation of a fluorinated silane. After removal of the polymer, these stamps were used to transfer thiol inks to a gold substrate by µCP. Gold patterns at a scale of less than 100,nm were successfully replicated by these chemically patterned flat PDMS stamps. [source] Microcontact Printing: Limitations and AchievementsADVANCED MATERIALS, Issue 22 2009András Perl Abstract Microcontact printing (µCP) offers a simple and low-cost surface patterning methodology with high versatility and sub-micrometer accuracy. The process has undergone a spectacular evolution since its invention, improving its capability to form sub-100,nm SAM patterns of various polar and apolar materials and biomolecules over macroscopic areas. Diverse development lines of µCP are discussed in this work detailing various printing strategies. New printing schemes with improved stamp materials render µCP a reproducible surface-patterning technique with an increased pattern resolution. New stamp materials and PDMS surface-treatment methods allow the use of polar molecules as inks. Flat elastomeric surfaces and low-diffusive inks push the feature sizes to the nanometer range. Chemical and supramolecular interactions between the ink and the substrate increase the applicability of the µCP process. [source] Microcontact Printing as a Versatile Tool for Patterning Organic Field - Effect Transistors,ADVANCED MATERIALS, Issue 12 2005R. Parashkov Patterning of organic field-effect transistors can be easily accomplished by microcontact printing combined with subsequent electroplating and electrode-peeling transfer. The method is based on area-selective electrodeposition and diffusion electropolymerization performed on metallized substrates with a previously patterned self-assembled monolayer, which is used as a template in the subsequent deposition of drain and source contacts (see Figure). [source] Microcontact Printing of CdS/Dendrimer Nanocomposite Patterns on Silicon Wafers,ADVANCED MATERIALS, Issue 5 2004C. Wu Micrometer-scale patterns of blue photoluminescing CdS nanoparticles can be produced by microcontact printing on a hydroxyl-terminated silicon wafer surface (see Figure). The CdS nanoparticles were synthesized with amine-terminated generation eight dendrimers as stabilizers. The resulting CdS/dendrimer composite is directly printable due to hydrogen bonds between dendrimer and surface. [source] Patterning of Electrostatic Charge on Electrets Using Hot Microcontact Printing,ANGEWANDTE CHEMIE, Issue 36 2009Dan Zhao Heiße Sache: Ein topographisch gemusterter Poly(dimethylsiloxan)(PDMS)-Stempel wird auf 50,220,°C erhitzt und nutzt dann diese Wärmeenergie als ,Tinte" für ein Mikrokontaktdrucken (,CP), indem er chemisches Vernetzen, Zersetzen oder andere Umwandlungen auslöst. Die Heiß-,CP-Technik kann Muster aus elektrostatischen Ladungen auf Elektreten durch selektive thermisch stimulierte Entladung (TSD, siehe Bild) oder Depolarisierung erzeugen. [source] Microcontact Printing: Limitations and AchievementsADVANCED MATERIALS, Issue 22 2009András Perl Abstract Microcontact printing (µCP) offers a simple and low-cost surface patterning methodology with high versatility and sub-micrometer accuracy. The process has undergone a spectacular evolution since its invention, improving its capability to form sub-100,nm SAM patterns of various polar and apolar materials and biomolecules over macroscopic areas. Diverse development lines of µCP are discussed in this work detailing various printing strategies. New printing schemes with improved stamp materials render µCP a reproducible surface-patterning technique with an increased pattern resolution. New stamp materials and PDMS surface-treatment methods allow the use of polar molecules as inks. Flat elastomeric surfaces and low-diffusive inks push the feature sizes to the nanometer range. Chemical and supramolecular interactions between the ink and the substrate increase the applicability of the µCP process. [source] Combinatorial Fabrication of Fluorescent Patterns with Metal Ions Using Soft Lithography,ADVANCED MATERIALS, Issue 8 2006L. Basabe-Desmonts A new combinatorial methodology for the fabrication and direct visualization of fluorescent and metal-ion micrometer patterns is presented. Microcontact printing is used to transfer different metal salts onto a variety of fluorescent monolayers on glass (see figure). [source] Symmetry-breaking in mammalian cell cohort migration during tissue pattern formation: Role of random-walk persistenceCYTOSKELETON, Issue 4 2005S. Huang Abstract Coordinated, cohort cell migration plays an important role in the morphogenesis of tissue patterns in metazoa. However, individual cells intrinsically move in a random walk-like fashion when studied in vitro. Hence, in the absence of an external orchestrating influence or template, the emergence of cohort cell migration must involve a symmetry-breaking event. To study this process, we used a novel experimental system in which multiple capillary endothelial cells exhibit spontaneous and robust cohort migration in the absence of chemical gradients when cultured on micrometer-scale extracellular matrix islands fabricated using microcontact printing. A computational model suggested that directional persistence of random-walk and dynamic mechanical coupling of adjacent cells are the critical control parameters for this symmetry-breaking behavior that is induced in spatially-constrained cell ensembles. The model predicted our finding that fibroblasts, which exhibit a much shorter motility persistence time than endothelial cells, failed to undergo symmetry breaking or produce cohort migration on the matrix islands. These findings suggest that cells have intrinsic motility characteristics that are tuned to match their role in tissue patterning. Our results underscore the importance of studying cell motility in the context of cell populations, and the need to address emergent features in multicellular organisms that arise not only from cell-cell and cell-matrix interactions, but also from properties that are intrinsic to individual cells. Cell Motil. Cytoskeleton 61:201,213, 2005. © 2005 Wiley-Liss, Inc. [source] Improved Microcontact Printing of Proteins using Hydrophilic Thermoplastic Elastomers as Stamp Materials,ADVANCED ENGINEERING MATERIALS, Issue 12 2007C. Trimbach Recently, the microstructuring of biological species, such as proteins, using microcontact printing (,CP), has become very popular. Microstructuring of proteins is useful for a variety of applications, such as biosensors, controlled cell growth and adhesion and microarrays for bioanalytical detection. Here the authors investigated the microcontact printing of proteins using a hydrophilic thermoplastic elastomeric stamp material. The emphasis is placed on the quality of the printed patterns with respect to inking time and protein concentration in the ink. [source] Planar Alignment of Columnar Discotic Liquid Crystals by Isotropic Phase Dewetting on Chemically Patterned SurfacesADVANCED FUNCTIONAL MATERIALS, Issue 6 2010Jonathan P. Bramble Abstract A novel method of creating planar aligned columnar discotic liquid crystals (cDLCs) on surfaces, which also gives control over the azimuthal angle, is presented. Surfaces are chemically patterned with stripes via microcontact printing of organothiol self-assembled monolayers (SAMs) on gold, or via deep UV patterning of organosilane SAMs on silicon. These are then used to isolate long droplets of cDLCs by dewetting in the isotropic phase. Upon cooling from the isotropic into the hexagonal columnar phase, polarizing microscopy reveals that the cDLC aligns in a planar orientation. Results for three triphenylene derivatives (HAT-6, HHTT, H7T) and for a phthalocyanine derivative (8H2Pc) are presented. H7T and HAT-6 are found to align with the director perpendicular to the stripe direction, but HHTT and 8H2Pc align parallel to the stripe direction. This relatively simple new method for creating planar aligned columnar phases of DLCs gives control over the azimuthal angle: a condition required for organic field-effect transistor applications of cDLCs. [source] Nanopatterning by an Integrated Process Combining Capillary Force Lithography and Microcontact PrintingADVANCED FUNCTIONAL MATERIALS, Issue 4 2010Xuexin Duan Abstract A novel nanopatterning process was developed by combining capillary force lithography (CFL) and microcontact printing (µCP). Flat polydimethylsiloxane (PDMS) was used as the substrate in CFL, and after chemical functionalization, as the stamp in µCP, which increased the resolution of both methods. The polymer patterns, produced by CFL on a thin polymer film on the flat PDMS substrate, acted as a mask to oxidize the uncovered regions of the PDMS. The chemical patterns were subsequently formed by gas phase evaporation of a fluorinated silane. After removal of the polymer, these stamps were used to transfer thiol inks to a gold substrate by µCP. Gold patterns at a scale of less than 100,nm were successfully replicated by these chemically patterned flat PDMS stamps. [source] Formation of Hierarchically Structured Thin FilmsADVANCED FUNCTIONAL MATERIALS, Issue 14 2009Ming Wang Abstract Here, we report the preparation of hierarchically structured polymer brushes with well-defined geometries via multiple step microcontact printing (MS-µCP) of inks containing different ratios of initiator-terminated thiols and non-reactive alkylthiols. Thick (and dense), polymer brushes grew from self-assembled monolayers (SAMs) with high concentration of initiator-terminated thiols, and these brushes exhibited high chemical etch-resistance, compared to thin (and less dense), brushes grown from more dilute initiator-terminated SAMs. Upon etching, patterned crosslinking polymer brush films decorated with thin layers of Au, could be lifted off the surface to form geometrically well-defined free-standing hierarchical films. These polymer brush films showed interesting buckling instabilities when compressed. Areas with different brush thicknesses and Au backing showed markedly different buckling behavior, leading to unusual patterns of wrinkles with different wavelengths and orientations toward the force field. [source] High-Resolution Contact Printing with Chemically Patterned Flat Stamps Fabricated by Nanoimprint LithographyADVANCED MATERIALS, Issue 27 2009Xuexin Duan Chemically patterned flat stamps provide an effective solution to avoid mechanical stamp-stability problems currently encountered in microcontact printing. A new method is developed to fabricate chemical patterns on a flat PDMS stamp using nanoimprint lithography. Sub-100,nm gold patterns are successfully replicated by these chemically patterned flat PDMS stamps. [source] Quartz Binding Peptides as Molecular Linkers towards Fabricating Multifunctional Micropatterned SubstratesADVANCED MATERIALS, Issue 3 2009Turgay 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] Microcontact Printing as a Versatile Tool for Patterning Organic Field - Effect Transistors,ADVANCED MATERIALS, Issue 12 2005R. Parashkov Patterning of organic field-effect transistors can be easily accomplished by microcontact printing combined with subsequent electroplating and electrode-peeling transfer. The method is based on area-selective electrodeposition and diffusion electropolymerization performed on metallized substrates with a previously patterned self-assembled monolayer, which is used as a template in the subsequent deposition of drain and source contacts (see Figure). [source] Stamps for Submicrometer Soft Lithography Fabricated by Capillary Force Lithography ,ADVANCED MATERIALS, Issue 13 2004M. Bruinink A convenient, inexpensive technique for fabrication of stamps for submicrometer soft lithography from masters with micrometer-size features is presented. Templates fabricated by capillary-force lithography are robust against replica molding of stamps. The Figure shows the resulting metal structure after employing such a second-generation stamp in microcontact printing of octadecanethiol and subsequent wet chemical etching of the underlying gold. [source] Fabrication of Diverse Microcapsule Arrays of High Density and Good StabilityMACROMOLECULAR RAPID COMMUNICATIONS, Issue 12 2010Jie Yang Abstract Microcapsule arrays attract a lot of interest due to their potential applications in sensing technology. A strategy for fabricating diverse microcapsule arrays through covalent linking is reported here. The self-assembly of microcapsules was directed by using a poly(allylamine hydrochloride) (PAH)-patterned template, which was created via microcontact printing. The microcapsules with PAH as the outermost layer were treated with glutaraldehyde and then covalently immobilized on the PAH regions, resulting in ordered microcapsule arrays. The arrays had a high density of capsules and the aggregate number in a pattern could be well controlled by adjusting the area of the PAH pattern. A single microcapsule array could be obtained if the diameter of the PAH region was smaller than that of the microcapsules. These covalently assembled arrays could survive through successive incubation in solutions of high ionic strength and extreme pHs. Such good stability ensures further treatments, such as chemical reactions and loading of functional substances. [source] Template-directed patterning of polymers and biomaterialsMICROSCOPY RESEARCH AND TECHNIQUE, Issue 6 2007Amol Chandekar Abstract A novel method of patterning surfaces with synthetic or biological polymers is demonstrated. It consists of using microcontact printing to pattern a gold surface with an adsorbate that imparts hydrophilicity; the remainder of the surface is covered with one that imparts hydrophobicity. 16-Mercaptohexadecanoic acid (MHDA) and 1H,1H,2H,2H-perfluorodecanethiol, respectively, have been used as the hydrophilic and hydrophobic adsorbates. This functionalized gold surface then serves as a template for patterning hydrophilic polymers and biomaterials, which are either spin-coated or drop-cast onto the surface. Using this methodology, it is shown by atomic force microscopy, scanning electron microscopy (SEM), and fluorescence microscopy that micron-scale patterns of a poly(ethylene)- block -poly(ethylene oxide) copolymer, poly- L -tryptophan, and bovine collagen can be fabricated, with these mimicking the MHDA patterns. For the block copolymer, it is found by atomic force microscopy that the heights of the polymer patterns decrease as their widths decrease. This is believed to be due to the inherent instability of tall, narrow polymer structures and the tendency of the polymer to minimize its exposed surface area. For poly- L -tryptophan, two different molecular weights of this polyamino acid have been studied, and different morphologies within the patterned regions are observed. While oligomeric poly- L -tryptophan (1,000,5,000 g/mol) gives smooth MHDA-covered patterns, the higher molecular weight (15,000,50,000 g/mol) yields fibrous ones. Microsc. Res. Tech., 2007. © 2007 Wiley-Liss, Inc. 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