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- 实验方案
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Edge Enriched Self-assembly of Au Nanoparticles: Coffee-Ring Effect during Microcontact Printing via Agarose Stamps
摘要： Amino functionalized surfaces were selectively modified via the combination of a wet agarose stamping technique and microcontact printing technique. Because of the specific reaction environments and diffusion of HNO2 confined in agarose stamp, the reaction of amino groups in the edge of the strip pattern was much more intense than other areas. The modified amino groups in the edge areas show higher affinity to Au-NPs than other areas, consequently, edge enriched Au-NPs patterns were observed after the self-assembly of Au-NPs. A “cylindrical droplet” model, in a manner analogous to coffee-ring effect, was proposed to describe the diffusion of HNO2 from the bulk to the edge in agarose stamp. By using such density varied Au-NPs patterns as templates for the growth of ZnO nanorods, we observed high density of Au-NPs resulting in high density and highly (001) oriented ZnO nanorods. In contrast, sparse and non-oriented ZnO nanorods were grew on low density of Au-NPs areas. Our findings might open new routes for the fabrication of gradient patterns and extend applications of Au-NPs patterns in surface enhanced Raman scattering and catalysis.
关键词： coffee-ring effect,gradient patterns,microcontact printing,agarose stamp,self-assembly
更新于2025-09-23 15:21:01
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Shaping Metallic Nanolattices: Design by Microcontact Printing from Wrinkled Stamps
摘要： A method for the fabrication of well-defined metallic nanostructures is presented here in a simple and straightforward fashion. As an alternative to lithographic techniques, this routine employs microcontact printing utilizing wrinkled stamps, which are prepared from polydimethylsiloxane (PDMS), and includes the formation of hydrophobic stripe patterns on a substrate via the transfer of oligomeric PDMS. Subsequent backfilling of the interspaces between these stripes with a hydroxyl-functional poly(2-vinyl pyridine) then provides the basic pattern for the deposition of citrate-stabilized gold nanoparticles promoted by electrostatic interaction. The resulting metallic nanostripes can be further customized by peeling off particles in a second microcontact printing step, which employs poly(ethylene imine) surface-decorated wrinkled stamps, to form nanolattices. Due to the independent adjustability of the period dimensions of the wrinkled stamps and stamp orientation with respect to the substrate, particle arrays on the (sub)micro-scale with various kinds of geometries are accessible in a straightforward fashion. This work provides an alternative, cost-effective, and scalable surface-patterning technique to fabricate nanolattice structures applicable to multiple types of functional nanoparticles. Being a top-down method, this process could be readily implemented into, e.g., the fabrication of optical and sensing devices on a large scale.
关键词： metallic nanolattices,oligomeric polydimethylsiloxane,microcontact printing,hydroxyl-functional poly(2-vinyl pyridine),gold,wrinkled stamps,nanoparticle assembly,polydimethylsiloxane wrinkles
更新于2025-09-23 15:19:57
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[IEEE 2018 International Symposium on Micro-NanoMechatronics and Human Science (MHS) - Nagoya, Japan (2018.12.9-2018.12.12)] 2018 International Symposium on Micro-NanoMechatronics and Human Science (MHS) - Uniform Transfection: Shock Wave Generation in Laser Ablation and Microcontact Printing
摘要： With the increasing need of regenerative medicines, cell therapy, and biopharmaceutical drug, it is necessary to develop a method for massively parallel delivery and uniform transfection. This research explores the possibility of using μCP (using cell adhesive and cell blocking agents) for printing massive number of cells on a substrate and using optoporation methods (nano-second pulsed radiation) to perforate cell membranes. With combining these two methods, a stand-alone micro-device capable of performing localized intracellular delivery will be developed. In this paper, we confirmed the generation of shock wave upon optoporation, tried intra-cellular delivery using Calcein, develop the stamp for micro-contact printing and performed the printing.
关键词： optoporation,laser ablation,uniform transfection,shock wave generation,microcontact printing
更新于2025-09-19 17:13:59
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Microcontact Printing with Laser Direct Writing Carbonization for Facile Fabrication of Carbon‐Based Ultrathin Disk Arrays and Ordered Holey Films
摘要： A nanometer-thick carbon film with a highly ordered pattern structure is very useful in a variety of applications. However, its large-scale, high-throughput, and low-cost fabrication is still a great challenge. Herein, microcontact printing (μCP) and direct laser writing carbonization (DLWc) are combined to develop a novel method that enables ease of fabrication of nanometer-thick and regularly patterned carbon disk arrays (CDAs) and holey carbon films (HCFs) from a pyromellitic dianhydride-oxydianiline-based polyamic acid (PAA) solution. The effect of PAA concentration and pillar lattice structure of the polydimethyl siloxane stamp are systematically studied for their influence on the geometrical parameter, surface morphology, and chemical structure of the finally achieved CDAs and HCFs. Within the PAA concentration being investigated, the averaged thickness of CDAs and HCFs can be tailored in a range from a few tens to a few hundred of nanometers. The μCP+DLWc-enabled electrically conductive CDAs and HCFs possess the characteristics of ease-of-fabrication, nanometer-thickness, highly regular and controlled patterns and structures, and the ability to form on both hard and soft substrates, which imparts usefulness in electronics, photonics, energy storage, catalysis, tissue engineering, as well as physical, chemical, and bio-sensing applications.
关键词： direct laser writing carbonization,holey carbon films,microcontact printing,carbon disk arrays
更新于2025-09-11 14:15:04
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Photothermally-Enhanced Molecular Delivery and Cellular Positioning on Patterned Plasmonic Interfaces
摘要： Photothermal conversion effect of plasmonic nanostructures is considered as a promising technique for cellular and molecular manipulations owing to controllability of local temperature. Therefore, this technique has been extensively applied to biological studies such as controlling cellular behavior, delivery of biologics, and biomolecular detection. Herein, we propose a novel method for directed cell positioning and photothermally-modulated molecular delivery to the cells using patterned plasmonic interfaces. Plasmonic substrates with gold nanorods (GNRs) and cell adhesion molecules fabricated by microcontact printing are optimized for cellular positioning on designated patterns. Through the photothermal conversion effect of GNRs on the pattern, we further demonstrate on-demand, light-induced delivery of drug molecules to the target cells. We expect that this approach will provide a new way to study single cellular behaviors and enhance molecular delivery to the target cells.
关键词： drug delivery,Photothermal conversion,gold nanorods,cell positioning,microcontact printing,plasmonic interfaces
更新于2025-09-11 14:15:04
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Reference Module in Materials Science and Materials Engineering || Sub-Micrometer Patterning Using Soft Lithography
摘要： The development of lithographic techniques that allow for controlling material properties at sub-micrometer length scales has become central to progress in many scientific and technological areas. In microelectronics, for example, optical lithography has enabled high-volume manufacturing of integrated circuits at ever-increasing density, complexity, and performance. This evolution has become possible in part through incremental changes toward shorter radiation wavelengths, high-index lens materials, advanced projection systems, and optimized resist formulations, pushing back the limits in resolution set by optical diffraction. By using current state-of-the-art step-and-repeat exposure tools it is possible, for example, to achieve a minimum transistor gate length of 20 nm and a dynamic random access memory periodicity (half-pitch) of 50 nm. Scanning beams of high-energy particles comprising atoms, ions, and electrons have also evolved into robust and mature technologies, which are being used for micro- and nanofabrication purposes. Each of these techniques can create arbitrary features at very high resolution (eg, 5 nm and below), but their serial nature limits the scope of applications to selected, low-volume fabrication tasks. Many of these techniques relies on complex and expensive equipment, making them unpractical for research in common laboratory environments. Moreover, they are not well suited for applications in a number of emerging fields, such as biotechnology or plastic electronics, where sensitive materials being incompatible with resist and development procedures, curved or uneven substrates, and large-areas are of primary concern.
关键词： replica molding,Soft lithography,sub-micrometer patterning,microcontact printing,edge-spreading lithography
更新于2025-09-04 15:30:14