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Letteratura scientifica selezionata sul tema "Microfabricatin"

Autore: Grafiati

Pubblicato: 31 agosto 2024

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Articoli di riviste sul tema "Microfabricatin"

De Maria, C., L. Grassi, F. Vozzi, A. Ahluwalia e G. Vozzi. "Development of a novel micro-ablation system to realise micrometric and well-defined hydrogel structures for tissue engineering applications". Rapid Prototyping Journal 20, n. 6 (20 ottobre 2014): 490–98. http://dx.doi.org/10.1108/rpj-03-2012-0022.

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Purpose – This paper aims to develop a novel micro-ablation system to realise micrometric and well-defined hydrogel structures. To engineer a tissue it is necessary to evaluate several aspects, such as cell-cell and cell-substrate interactions, its micro-architecture and mechanical stimuli that act on it. For this reason, it is important to fabricate a substrate which presents a microtopology similar to natural tissue and has chemical and mechanical properties able to promote cell functions. In this paper, well-defined hydrogel structures embedding cells were microfabricated using a purposely developed technique, micro-laser ablation, based on a thulium laser. Its working parameters (laser power emission, stepper motor velocity) were optimised to produce shaded “serpentine” pattern on a hydrogel film. Design/methodology/approach – In this study, initially, swelling/contraction tests on agarose and alginate hydrogel in different solutions of main components of cell culture medium were performed and were compared with the MECpH model. This comparison matched with good approximation experimental measurements. Once known how hydrogel changed its topology, microstructures with a well-defined topology were realised using a purposely developed micro-laser ablation system design. S5Y5 neuroblastoma cell lines were embedded in hydrogel matrix and the whole structure was ablated with a laser microfabrication system. The cells did not show damages due to mechanical stress present in the hydrogel matrix and to thermal increase induced by the laser beam. Findings – The hydrogel structure is able to reproduce extracellular matrix. Initially, the hydrogel swelling/contraction in different solutions, containing the main components of the most common cell culture media, was analysed. This analysis is important to evaluate if cell culture environment could alter microtopology of realised structures. Then, the same topology was realised on hydrogel film embedding neuronal cells and the cells did not show damages due to mechanical stress present in the hydrogel matrix and to thermal increase induced by the laser beam. The interesting obtained results could be useful to realise well-defined microfabricated hydrogel structures embedding cells to guide tissue formation Originality/value – The originality of this paper is the design and realisation of a 3D microfabrication system able to microfabricate hydrogel matrix embedding cells without inducing cell damage. The ease of use of this system and its potential modularity render this system a novel potential device for application in tissue engineering and regenerative medicine area.

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Du, L. Q., C. Liu, H. J. Liu, J. Qin, N. Li e Rui Yang. "Design and Fabrication of Micro Hot Embossing Mold for Microfluidic Chip Used in Flow Cytometry". Key Engineering Materials 339 (maggio 2007): 246–51. http://dx.doi.org/10.4028/www.scientific.net/kem.339.246.

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Micro hot embossing mold of microfluidic chip used in flow cytometry is designed and microfabricated. After some kinds of microfabrication processes are tried, this paper presents a novel microfabrication technology of micro hot embossing metal mold. Micro metal mold is fabricated by low-cost UV-LIGA surface micro fabrication process using negative thick photoresist, SU-8. Different from other micro hot embossing molds, the micro mold with vertical sidewalls is fabricated by micro nickel electroforming directly on Nickel base. Based on the micro Nickel mold and automation fabrication system, high precision and mass-producing microfluidic chips have been fabricated and they have been used in flow cytometry

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Han, Lei, Pingmei Ming, Shen Niu, Guangbin Yang, Dongdong Li e Kuaile Cheng. "Microfabricating Mirror-like Surface Precision Micro-Sized Amorphous Alloy Structures Using Jet-ECM Process". Micromachines 15, n. 3 (11 marzo 2024): 375. http://dx.doi.org/10.3390/mi15030375.

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Amorphous alloy (AA) is a high-performance metal material generally with significantly excellent mechanical and corrosion resistance properties and thus is considered as a desirable material selection for micro-scale articles. However, the microfabrication of AA still faces a variety of technical challenges mainly because the materials are too hard to process and easily lose their original properties, although at moderately high temperatures. In this study, jet-electrolyte electrochemical machining (Jet-ECM) was proposed to microfabricate the Zr-based AA because it is a low-temperature material-removal process based on the anode dissolution mechanism. The electrochemical dissolution characteristics and material removal mechanism of AA were investigated, and then the optimal process parameters were achieved based on the evaluation of the surface morphologies, surface roughness, geometrical profile, and machining accuracy of the machined micro-dimples. Finally, the feasibility was further studied by using Jet-ECM to fabricate arrayed micro-dimples using the optimized parameters. It was found that Jet-ECM can successfully microfabricate mirror-like surface AA arrayed precision micro-dimples with significantly high dimensional accuracy and geometrical consistency. Jet-ECM is a promisingly advantageous microfabrication process for the hard-to-machine AA.

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Folch, A., A. Ayon, O. Hurtado, M. A. Schmidt e M. Toner. "Molding of Deep Polydimethylsiloxane Microstructures for Microfluidics and Biological Applications". Journal of Biomechanical Engineering 121, n. 1 (1 febbraio 1999): 28–34. http://dx.doi.org/10.1115/1.2798038.

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Here we demonstrate the microfabrication of deep (>25 μm) polymeric microstructures created by replica-molding polydimethylsiloxane (PDMS) from microfabricated Si substrates. The use of PDMS structures in microfluidics and biological applications is discussed. We investigated the feasibility of two methods for the microfabrication of the Si molds: deep plasma etch of silicon-on-insulator (SOI) wafers and photolithographic patterning of a spin-coated photoplastic layer. Although the SOI wafers can be patterned at higher resolution, we found that the inexpensive photoplastic yields similar replication fidelity. The latter is mostly limited by the mechanical stability of the replicated PDMS structures. As an example, we demonstrate the selective delivery of different cell suspensions to specific locations of a tissue culture substrate resulting in micropatterns of attached cells.

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Banerjee, Arunav S., Richard Blaikie e Wen Hui Wang. "Microfabrication Process for XYZ Stage-Needle Assembly for Cellular Delivery and Surgery". Materials Science Forum 700 (settembre 2011): 195–98. http://dx.doi.org/10.4028/www.scientific.net/msf.700.195.

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In this paper, we present our ongoing work on developing a microfabricated XYZ stage-needle arrayed single crystal silicon (SCS) structure for cellular delivery and surgery. We discuss the device design and working principle based on electrostatic actuation. We also briefly discuss our microfabrication process flow and show some preliminary results of fabricating arrays of microneedles that are 250 µm long and 5 µm at the tip diameter.

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PARK, W. B., J. H. CHOI, C. W. PARK, G. M. KIM, H. S. SHIN, C. N. CHU e B. H. KIM. "FABRICATION OF MICRO PROBE-TYPE ELECTRODES FOR MICROELECTRO-CHEMICAL MACHINING USING MICROFABRICATION". International Journal of Modern Physics B 24, n. 15n16 (30 giugno 2010): 2639–44. http://dx.doi.org/10.1142/s0217979210065398.

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In this study, the mass fabrication of microelectrode tools for microelectrochemical machining (MECM) was studied using microfabrication processes. The cantilever type geometry of microelectrodes was defined by photolithography processes, and metal patterns were made for electrical contacts. Various fabrication processes were studied for the fabrication of microelectrode tools, such as wet etching, lift-off, and electroforming for metal layer patterning. MECM test results showed feasibility of the fabricated electrode tools. The microfabricated electrodes can be used as micromachining tools for various electrical micromachining of steel mold and parts of microdevices.

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Liu, Yue, Megan Chesnut, Amy Guitreau, Jacob Beckham, Adam Melvin, Jason Eades, Terrence R. Tiersch e William Todd Monroe. "Microfabrication of low-cost customisable counting chambers for standardised estimation of sperm concentration". Reproduction, Fertility and Development 32, n. 9 (2020): 873. http://dx.doi.org/10.1071/rd19154.

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Evaluation of sperm concentration is essential for research and procedures involving AI, cryopreservation and sperm quality assessment. Microfabrication technologies have shown tremendous potential for rapid prototyping and fabrication of devices to assist reproduction and fertility research, but such utility has not yet been made available for most reproduction laboratories. The aim of this study was to evaluate the feasibility of using microfabrication techniques to produce counting chambers for estimation of sperm concentration. Zebrafish (Danio rerio) spermatozoa were used as a model for evaluation of functionality of the chambers. These microfabricated enumeration grid chambers (MEGC) were composed of a polydimethylsiloxane (PDMS) coverslip with grid patterns (100 μm×100 μm) and a PDMS base platform to create a known volume with a 10-μm height to restrict the cells to a single layer. The results of cell counts estimated by two of three prototype MEGC devices tested were not significantly different from the control device, a commercially available Makler chamber. The material cost for a MEGC was less than US$0.10 compared with product costs of approximately US$100 for a standard haemocytometer and US$700 for a Makler counting chamber. This study demonstrates the feasibility of microfabrication in creating low-cost counting chambers to enhance standardisation and strengthen interdisciplinary collaborations.

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Alvarez-Escobar, Marta, Sidónio C. Freitas, Derek Hansford, Fernando J. Monteiro e Alejandro Pelaez-Vargas. "Soft Lithography and Minimally Human Invasive Technique for Rapid Screening of Oral Biofilm Formation on New Microfabricated Dental Material Surfaces". International Journal of Dentistry 2018 (2018): 1–5. http://dx.doi.org/10.1155/2018/4219625.

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Introduction. Microfabrication offers opportunities to study surface concepts focused to reduce bacterial adhesion on implants using human minimally invasive rapid screening (hMIRS). Wide information is available about cell/biomaterial interactions using eukaryotic and prokaryotic cells on surfaces of dental materials with different topographies, but studies using human being are still limited. Objective. To evaluate a synergy of microfabrication and hMIRS to study the bacterial adhesion on micropatterned surfaces for dental materials. Materials and Methods. Micropatterned and flat surfaces on biomedical PDMS disks were produced by soft lithography. The hMIRS approach was used to evaluate the total oral bacterial adhesion on PDMS surfaces placed in the oral cavity of five volunteers (the study was approved by the University Ethical Committee). After 24 h, the disks were analyzed using MTT assay and light microscopy. Results. In the present pilot study, microwell structures were microfabricated on the PDMS surface via soft lithography with a spacing of 5 µm. Overall, bacterial adhesion did not significantly differ between the flat and micropatterned surfaces. However, individual analysis of two subjects showed greater bacterial adhesion on the micropatterned surfaces than on the flat surfaces. Significance. Microfabrication and hMIRS might be implemented to study the cell/biomaterial interactions for dental materials.

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Starodubov, Andrey, Roman Torgashov, Viktor Galushka, Anton Pavlov, Vladimir Titov, Nikita Ryskin, Anand Abhishek e Niraj Kumar. "Microfabrication, Characterization, and Cold-Test Study of the Slow-Wave Structure of a Millimeter-Band Backward-Wave Oscillator with a Sheet Electron Beam". Electronics 11, n. 18 (9 settembre 2022): 2858. http://dx.doi.org/10.3390/electronics11182858.

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In this paper, the results of the microfabrication, characterization, and cold-test study of the previously proposed truncated sine-waveguide interaction structure with wideband-matched output couplers for the millimeter-band backward-wave oscillator (BWO) driven by a high-current-density sheet electron beam are presented. Computer-numerical-control (CNC) micromilling was used to fabricate the designed interaction structure. The first sample was microfabricated from an aluminum alloy to test the milling process. The final sample was made from oxygen-free copper. Scanning electron microscopy (SEM) and optical microscopy were used to investigate the morphology of the microfabricated samples, and stylus profilometry was used to estimate the level of the surface roughness. Cold S-parameters were measured in Q- and V-bands (40–70 GHz), using a vector network analyzer (VNA). Using the experimentally measured phase data of the transmitted signal, the dispersion of the fabricated interaction structure was evaluated. The experimentally measured dispersion characteristic is in good agreement with the numerically calculated.

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Creff, Justine, Laurent Malaquin e Arnaud Besson. "In vitro models of intestinal epithelium: Toward bioengineered systems". Journal of Tissue Engineering 12 (gennaio 2021): 204173142098520. http://dx.doi.org/10.1177/2041731420985202.

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The intestinal epithelium, the fastest renewing tissue in human, is a complex tissue hosting multiple cell types with a dynamic and multiparametric microenvironment, making it particularly challenging to recreate in vitro. Convergence of recent advances in cellular biology and microfabrication technologies have led to the development of various bioengineered systems to model and study the intestinal epithelium. Theses microfabricated in vitro models may constitute an alternative to current approaches for studying the fundamental mechanisms governing intestinal homeostasis and pathologies, as well as for in vitro drug screening and testing. Herein, we review the recent advances in bioengineered in vitro intestinal models.

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Più fonti

Tesi sul tema "Microfabricatin"

Feng, Chunhua. "Microfabrication-compatible synthesis strategies for nanoscale electrocatalysts in microfabricated fuel cell applications /". View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?CENG%202007%20FENG.

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Grebille, Bénédicte. "Photopolymérisation radicalaire contrôlée par ATRP : études mécanistiques, applications en sciences des matériaux et perspectives en microfabrication". Electronic Thesis or Diss., Lyon, École normale supérieure, 2024. http://www.theses.fr/2024ENSL0017.

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Au début du XXème siècle, Giacomo Luigi Ciamician, physico-chimiste, a mis en évidence l'intérêt de recourir à la lumière comme source d'énergie renouvelable pour des réactions chimiques. À la fin du siècle, la découverte de la polymérisation radicalaire contrôlée, notamment l'ATRP (« Atom Transfer Radical Polymerization »), a marqué une avancée majeure dans la chimie des polymères. Cette technique a été largement développée et utilisée dans divers domaines, notamment pour la fonctionnalisation de surfaces à travers l'ATRP amorcée sur surface (« Surface Initiated ATRP », SI-ATRP), offrant ainsi des applications variées allant de la biologie à l'ingénierie des matériaux. La présente thèse vise principalement à explorer l'utilisation de l'ATRP photoinduite dans le domaine de la microfabrication. Pour ce faire, un nouveau système multicomposants pour l'ATRP photoinduite a été développé et étudié en détail du point de vue physico-chimique. La compréhension en profondeur de l’impact de chaque constituant du système a permis d’atteindre de la polymérisation de manière hautement contrôlée dans de nombreuses conditions, entre autres à l’air libre. De plus, ce système, comprenant un photosensibilisateur capable d'effectuer une absorption à deux photons, a pu être appliqué à diverses fins. Il a permis de réaliser de l'ATRP amorcée sur surface sous atmosphère inerte mais également en présence de dioxygène. L'optimisation de cette technique de fonctionnalisation de surface a été effectuée en vue de son utilisation pour la microfabrication. De plus, ce système multicomposants a facilité la synthèse, par ATRP photoinduite, de photosensibilisateurs hydrosolubles, dotés de propriétés d'absorption à deux photons, à partir d'un nouveau macrophotoamorceur. Cette famille de macromolécules s'est avérée efficace pour le photoamorçage de polymérisation en émulsion, ouvrant ainsi la voie à des polymérisations en émulsion photoinduites à deux photons et possiblement à la microfabrication d’hydrogels
In the early 20th century, the physico-chemist Giacomo Luigi Ciamician, highlighted the benefits of using light as a suitable energy source for chemical reactions. At the end of this same century, the discovery of controlled radical polymerization, in particular ATRP (Atom Transfer Radical Polymerization), marked a major advance in polymer chemistry. This technique has been widely developed and used in a variety of fields, including surface functionalization through Surface Initiated ATRP (SI-ATRP), with applications ranging from biology to materials engineering. The main aim of this thesis is to explore the use of photoinduced ATRP in microprinting. For this purpose, a new multicomponent system for photoinduced ATRP has been developed and studied in detail from a physicochemical point of view. The thorough understanding of each component impact of the system has enabled to reach highly controlled polymerization under a wide variety of conditions, including in the open air. Moreover, this system, which includes a photosensitizer capable of two-photon absorption, has been used for a variety of purposes. It has been used to perform surface-initiated ATRP both in an inert atmosphere and in the presence of dioxygen. The optimization of the surface functionalization technique was used for microprinting. Furthermore, this multicomponent system facilitated the synthesis, by photoinduced ATRP from a new macrophotoinitiator, of water-soluble photosensitizers with interesting biphotonic absorption properties. This family of macromolecules has proved to be effective in photoinitiating emulsion polymerization, paving the way for two-photon photoinduced emulsion polymerization and potentially also to hydrogels microprinting

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Altay, Gizem. "Towards the development of biomimetic in vitro models of intestinal epithelium derived from intestinal organoids". Doctoral thesis, Universitat de Barcelona, 2018. http://hdl.handle.net/10803/664864.

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Intestinal epithelium is highly specialized tissue organized into crypt-villus units relevant for their effective barrier function and nutrient absorption. In the crypt units reside the proliferative intestinal stem cells (ISCs) that divide and differentiate while migrating along the villi to generate the epithelium. The proliferation, migration and differentiation of ISCs is governed by the tightly controlled spatio-chemical gradients of ISC niche factors; bone morphogenic protein (BMP), wingless/Int (Wnt) and epidermal growth factor (EGF) pathway modulators. In vitro models of the intestinal epithelium, for the most part, based on culturing of intestinal stem cells/crypts in 3D cultures forming structures called organoids. These structures faithfully recapture diverse cell populations and their multicellular organization of native intestinal epithelium. However, 3D closed geometry of intestinal organoids prevents access to the apical region of the epithelium, making them unsuitable for conventional functionality assays. Experimental modeling of intestinal epithelial biology and physiology are limited due to the lack in vitro platforms that recapitulate these key aspects of the small intestinal epithelium: its distinct cell populations, 3D architecture and the gradients of ISC niche biochemical factors along the crypt-villus axis. Here, we describe development of in vitro models of intestinal epithelium obtained from intestinal organoid-derived crypts. First, we present a method that takes the advantage of substrate stiffness to dictate the formation of monolayers with accessible lumen rather than 3D organoids with a closed geometry. The 2D intestinal epithelium model has in vivo-like crypt-villus cellular organization with all major epithelial cell types and show physiologically relevant tissue barrier function. Then, we describe the development of a more complex model of intestinal epithelium by incorporating a 3D villus-like basement membrane substitute fabricated on hydrogels. For that, poly(ethylene glycol) diacrylate (PEGDA) hydrogels are chosen due to their highly tunable chemical, and mechanical properties, porosity and photocrosslinkable nature allowing easy microstructuring. The formation of 3D bullet-like complex shapes was achieved by photolithography-based crosslinking of PEGDA, a simple, cost-effective approach. The bioactive functionalization of otherwise inert PEGDA for cell adhesion, was achieved by copolymerizing it with acrylic acid and a variety of cell adhesion proteins can be covalently anchored to the 3D villus-like hydrogels. We establish the optimal conditions for the growth of intestinal organoid-derived epithelial monolayers and demonstrated that organoid-derived intestinal epithelial cells successfully formed epithelial monolayers on collagen type I functionalized 3D villus-like PEGDA-acrylic acid hydrogels. Finally, we describe methods to create spatiotemporal gradients of biochemical ISC niche factors on 3D villus-like hydrogels and demonstrate that these gradients can be used to compartmentalize the differentiated epithelial cells. The spatio-chemical gradients of ISC niche biochemical factors on PEGDA hydrogels with proper porosity were successfully generated based on the free diffusion of the factors from a source to a sink chamber in a custom-made microfluidic device allocating the hydrogel and visualized with light-sheet fluorescence microscopy. In silico models were developed to simulate the spatio-chemical gradients formed within the hydrogels. The 3D villus-like PEGDA hydrogels were fabricated on porous membranes and successfully adapted to Transwell® inserts that permitted access to both sides of the hydrogel and the generation of spatio-chemical gradients. The gradients generated in this fashion can be used to compartmentalize the differentiated epithelial cells more towards the tips of the villus-like microstructures. The 3D villus-like platform improves the current models in providing cells with physiologically representative topographical and mechanical cues and biochemical gradients. Due to its utility, this platform might find uncountable applications. It can be used for the understanding of the basic biology of the intestinal epithelium. In addition, it can be used to culture human intestinal stem cells allowing for the screening of novel therapies and disease modeling.
El epitelio intestinal es un tejido altamente especializado, organizado en unidades de criptas y vellosidades que son relevantes para sus eficaces funciones de barrera y absorción de nutrientes. En las unidades de criptas residen las células madre intestinales (ISC) proliferativas que se dividen y diferencian mientras migran a lo largo de las vellosidades, las cuales generan el epitelio maduro. En el epitelio maduro, las ISC y las células proliferativas se localizan en las criptas y las células absorbentes y secretoras diferenciadas en las vellosidades. La proliferación, migración y diferenciación de las ISC se rigen por los gradientes químicos espaciales altamente controlados de los factores de nicho de la ISC; Moduladores de la vía de bone morphogenic protein (BMP), wingless/Int (Wnt) y epidermal growth factor (EGF). El modelado experimental de la biología y la fisiología del epitelio intestinal está limitado debido a la falta de plataformas in vitro que recapitulan estos aspectos clave del epitelio del intestino delgado: sus distintas poblaciones celulares, la arquitectura 3D y los gradientes de factores bioquímicos de nicho ISC a lo largo del eje cripta-vellosidad. Aquí, describimos el desarrollo de modelos in vitro de epitelio intestinal obtenidos de criptas derivadas de organoides intestinales. En primer lugar, presentamos un método para obtener monocapas epiteliales intestinales 2D con lumen accesible y función de barrera fisiológica. A continuación, describimos el desarrollo de andamios biomiméticos 3D similares a vellosidades en hidrogeles de diacrilato de polietilenglicol (PEGDA) utilizando un enfoque fotolitográfico simple y rentable. Demostramos que nuestra plataforma de vellosidades sintéticas apoya la formación de monocapas epiteliales de células epiteliales intestinales derivadas de organoides. Finalmente, describimos métodos para crear gradientes espaciotemporales de factores nicho bioquímicos ISC en hidrogeles 3D similares a vellosidades y demostramos que estos gradientes se pueden usar para compartimentar las células epiteliales diferenciadas. La plataforma 3D que recrea las vellosidades intestinalesmejora los modelos actuales al proporcionar a las células las señales topográficas y mecánicas y los gradientes bioquímicos fisiológicamente representativos. Debido a su utilidad, esta plataforma puede encontrar innumerables aplicaciones. Puede ser utilizada para la comprensión de la biología básica del epitelio intestinal. Además, se puede utilizar para cultivar células madre intestinales humanas que permitan la detección de nuevas terapias y el modelado de enfermedades.

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Caballero, Lucas Francesc. "Z-scan methods for ultrashort pulsed laser microprocessing of transparent materials". Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/668185.

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The use of femtosecond lasers has recently gained attention as a result of the recognition to Gérard Mourou and Donna Strickland with the award of the Nobel Prize in Physics 2018 "for their method of generating high-intensity, ultra-short optical pulses". The innumerable areas of application of ultrashort laser pulses have not yet been completely explored, but their possibilities for accessing the microworld are considered highly valuable. Following this spirit, the objective of this thesis consisted in proposing and implementing feasible solutions to the challenges involved in the microfabrication of materials with ultrashort laser pulses for diverse advanced applications. To that end, attention was put in laser ablation of transparent polymers with spatial resolutions that transcend sharpness limitations due to light diffraction. The results presented here were obtained during the development of the doctorate studies of the PhD program in Nanosciences at the Departament de Física Aplicada of the Universitat de Barcelona. It is structured as follows: INTRODUCTION AND OBJECTIVES: This introductory chapter contains a description of the most significant microfabrication techniques, centered on laser-based methods. Having a key role in this thesis, the interaction between laser radiation and matter is shortly reviewed. The physical phenomena motivate the use of femtosecond lasers for the precise processing of transparent materials, where focus is put on their superficial laser ablation, the entailing challenges and its applications. The objectives pursued in this work close this first chapter. EXPERIMENTAL: A description of the experimental setups implementing femtosecond laser systems, methods and materials applied during the trials constituting the developed research is presented in this chapter. The features of the laser sources together with the corresponding laser direct-write setups form the sections of this chapter, followed by some comments on Gaussian beams and their focusing. These found the presentation of the z-scan focusing technique. To close this chapter, some remarks and background about the employed materials are delivered. Z-SCAN FOCUSING METHOD: The results obtained by putting to work the z-scan focusing technique introduced in the previous chapter are presented here. The theme is the development and characterization of the z-scan focusing technique as a method to address the issue of securing surface ablation of transparent material with femtosecond laser pulses. Its successful implementation in surface ablation of the transparent polymer polymethyl methacrylate (PMMA) with high spatial resolution is given as proof of the viability of the proposed strategy for a precise focusing of laser beams onto transparent materials. The contents of this chapter include studies on transmittance and reflectance measurements at different focusing distances between the laser beam waist and the processed material surface through single laser pulse surface ablation and laser surface scanning for channel microfabrication (comparing their results), the beam waist position determination thanks to the transmittance measurements and analysis of the produced surface ablation. APPLICATIONS IN LASER MICROFABRICATION OF MATERIALS: the implementation of the developed z- scan focusing technique was put to use in laser microfabrication of materials with diverse applications. The applications include the irradiation with femtosecond laser pulses of biodegradable polymers for profound hole ablation in polylactic acid (PLA) and study of the its influence in biodegradability of polylactic-co-glycolic acid, the laser perforation for leakage studies on medical use polypropylene bags, and the laser fabrication of microfluidic guides for conductive line printing. Owing to their diversity the chapter is divided in four sections, one for each topic. The various processed materials are briefly introduced, with some background supporting their study. CONCLUSIONS: The last chapter sums up the most relevant results and main achievements that have been obtained during the development of this thesis in the form of closing remarks.
L’ús de làsers d’impulsos ultracurts ha rebut atenció recentment degut al reconeixement amb el Premi Nobel de Física de l’any 2018 a la tècnica que en permet la seva generació. Les seves àrees d’aplicació encara no han estat completament explorades, però les seves possibilitats per accedir al món microscòpic són considerades prometedores. Seguint aquest esperit, l’objectiu d’aquesta tesi és proposar i implementar solucions viables als reptes relacionats amb la microfabricació de materials amb impulsos làser ultracurts, específicament l’ablació làser de polímers transparents amb resolucions espacials que transcendeixin les limitacions de definició associades a la difracció de la llum. INTRODUCCIÓ I OBJECTIUS: Aquest capítol descriu les tècniques de microfabricació més significatives, centrant-se en els mètodes làser. Degut al paper clau del làser en aquesta tesi, es fa una descripció breu de la interacció entre la radiació làser i la matèria. Els objectius plantejats completen aquest primer capítol. EXPERIMENTAL: En aquest apartat es presenta una descripció dels muntatges experimentals amb sistemes làser de duració ultracurta, els mètodes i els materials emprats durant les proves que constitueixen la recerca i que serveixen de base per a la presentació del mètode d’enfocament z-scan. MÈTODE D’ENFOCAMENT Z-SCAN: Els resultats obtinguts amb la tècnica proposada d’enfocament per z-scan són presentats aquí. El tema central és el desenvolupament i caracterització d’aquesta tècnica com a mètode per l’ablació superficial de materials transparents amb impulsos làser ultracurts. La implementació exitosa de l’ablació superficial del polimetilmetacrilat (PMMA) amb elevada resolució espacial demostra la viabilitat de l’estratègia proposada per enfocar amb precisió un feix làser a la superfície de materials transparents. APLICACIONS PER AL MICROPROCESSAMENT LÀSER DE MATERIALS: La implementació de la tècnica desenvolupada d’enfocament per z-scan s’ha pogut traslladar al microprocessament de materials amb làser en diverses aplicacions com la irradiació de polímers biodegradables per a la producció de forats profunds en àcid polílàctic (PLA), la seva influència en la biodegradabilitat de l’àcid polílàctic-co-glicòlic (PLGA), la perforació de fuites en bosses de polipropilè d’ús mèdic, i la fabricació de guies microfluídiques per la impressió de línies conductores. Conclusions: L’últim capítol resumeix els resultats més rellevants i els principals assoliments.

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Cannon, Andrew Hampton. "Unconventional Microfabrication Using Polymers". Thesis, Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/19845.

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Current microfabrication materials include silicon, a wide variety of metals, dielectrics, and some polymers. Because of the low cost and high processing flexibility that polymers generally have, expanding the use of polymers in microfabrication would benefit the microfabrication community, enabling new routes towards goals such as low-cost 3D microfabrication. This work describes two main unconventional uses of polymers in microfabrication. The first unconventional use is as a carrier material in the self-assembly (SA) of millimeter-scale parts in which functional electronic components and electrical interconnects were cast into 5 mm cubes of Polymethylmethacrylate (PMMA). The second unconventional use is as a non-flat micromold for an alumina ceramic and as transfer material for multiple layers of micropatterned carbon nanotubes (CNTs). Both of these uses demonstrate 3D low-cost microfabrication routes. In the SA chapter, surface forces induced both gross and fine alignment of the PMMA cubes. The cubes were bonded using low-melting temperature solder, resulting in a self-assembled 3D circuit of LEDs and capacitors. The PMMA-encasulated parts were immersed in methyl methacrylate (MMA) to dissolve the PMMA, showing the possibility of using MEMS devices with moving parts such as mechanical actuators or resonators. This technique could be expanded for assembly of systems having more than 104 components. The ultimate goal is to combine a large number of diverse active components to allow the manufacture of systems having dense integrated functionality. The ceramic micromolding chapter explores micromolding fabrication of alumina ceramic microstructures on flat and curved surfaces, transfer of carbon nanotube (CNT) micropatterns into the ceramic, and oxidation inhibition of these CNTs through ceramic encapsulation. Microstructured master mold templates were fabricated from etched silicon, embossed thermally sacrificial polymer, and flexible polydimethylsiloxane (PDMS). The polymer templates were themselves made from silicon masters. Thus, once the master is produced, no further access to a microfabrication facility is required. Using the flexible PDMS molds, ceramic structures with mm-scale curvature were fabricated having microstructures on either the inside or outside of the curved macrostructure. It was possible to embed CNTs into the ceramic microstructures. To do this, micropatterned CNTs on silicon were transferred to ceramic via vacuum molding. Multilayered micropatterned CNT-ceramic devices were fabricated, and CNT electrical traces were encapsulated with ceramic to inhibit oxidation. During oxidation trials, encapsulated CNT traces showed an increase in resistance that was 62% less than those that were not encapsulated.

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Florian, Baron Camilo. "Laser direct-writing for microfabrication". Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/400403.

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Digital manufacturing constitutes a real industrial revolution that is transforming the production processes from the early stages of research and development to mass production and marketing. The biggest difference in comparison with old fabrication methods is the possibility to perform changes in the pattern design just by using mouse clicks instead of modifying an already fabricated prototype, which results in faster, cheaper and more efficient fabrication processes. For example, new technologies enabling the production of printed electronic devices on flexible substrates and compatible with roll-to-roll processing methods would result in cheaper fabrication costs than the traditional batch processing of silicon wafers. Such fabrication methods comprise a series of processing steps which are applied to the substrates while they are moving on rolls in the fabrication line. Therefore, it is desired that the new technologies can work at high speeds allowing at the same time the production of miniaturized features. Lasers are a versatile tool that can meet the demands of flexibility, speed, resolution and compatibility with roll-to-roll processing of digital manufacturing. The main advantages of laser radiation rely in its unique properties: high directionality, coherence and monochromaticity. The combination of such properties allows generating high intensities that can be focused into extremely small volumes, which makes lasers an ideal tool for the processing of materials at the micro- and nano-scale, not only as a subtractive but also as an additive technique. Laser ablation is the best known subtractive technique and it consists in the irradiation of a material with a focused laser beam. In the case of working with transparent materials, surface ablation constitutes a serious challenge since it is necessary to develop new strategies that allow controlling the position where the energy is delivered to ensure that ablation really occurs in the surface without modifying the bulk material. On the other hand, lasers can also be used as additive tools. For example, laser-induced forward transfer (LIFT) allows the transfer of materials in both solid and liquid state with high spatial resolution. In spite of the extensive amount of research on LIFT, some challenges still remain. For instance, the understanding of the particular printing dynamics encountered during the high speed printing of liquids, or the problem of printing uniform, continuous and stable lines with high spatial resolution. The objective of this thesis is to propose and implement feasible solutions to some of the challenges that are associated with both the subtractive and additive laser based techniques presented above. On one side, we study the laser ablation of transparent polymers using femtosecond laser pulses with the aim of achieving spatial resolutions that overcome the diffraction limit, and at the same time solving the problem of the required precise focusing of the laser beam on the materials surface. On the other side, we study the LIFT transfer dynamics during the high speed printing of liquids, and we propose alternative printing strategies to solve the inherent quality defects usually encountered during the formation of printed lines. Finally, two different approaches that are a combination of both subtractive and additive techniques are presented; we implement LIFT for the fabrication of liquid microlenses used for the surface nanopatterning of materials, and on the other side, we create fluidic guides by laser ablation for the printing of high quality continuous lines.
La fabricació digital de dispositius tecnològics requereix el desenvolupament de noves i millors tècniques per al microprocessament de materials que al mateix temps siguin compatibles amb mètodes de producció en sèrie a gran escala com el roll-to-roll processing. Aquestes tècniques han de complir certs requisits relacionats amb la possibilitat de realitzar canvis de disseny ràpids durant el procés de fabricació, alta velocitat de processament, i al mateix temps permetre la producció de motius de forma controlada amb altes resolucions espacials. En la present tesi es proposen i implementen solucions viables a alguns dels reptes presents a la microfabricació amb làser tant substractiva com additiva. D'una banda, es presenta un nou mètode d'enfocament del feix làser sobre la mostra per l'ablació superficial de materials transparents que permet obtenir resolucions espacials que superen el límit de difracció del dispositiu òptic. D'altra banda, es duu a terme un estudi de la dinàmica de la impressió de líquids mitjançant làser a alta velocitat, de gran interès de cara a la implementació industrial de la tècnica. A més, es presenten estratègies d'impressió de tintes conductores amb l'objectiu de produir línies contínues amb alta qualitat d'impressió. Finalment s'inclouen dues propostes que són producte de la combinació d’ambues tècniques, la impressió de líquids i l'ablació amb làser.

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Wang, Weihua. "Tools for flexible electrochemical microfabrication /". Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/9854.

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Barham, Oliver M. "Microfabricated Bulk Piezoelectric Transformers". Thesis, University of Maryland, College Park, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10615552.

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Piezoelectric voltage transformers (PTs) can be used to transform an input voltage into a different, required output voltage needed in electronic and electro- mechanical systems, among other varied uses. On the macro scale, they have been commercialized in electronics powering consumer laptop liquid crystal displays, and compete with an older, more prevalent technology, inductive electromagnetic volt- age transformers (EMTs). The present work investigates PTs on smaller size scales that are currently in the academic research sphere, with an eye towards applications including micro-robotics and other small-scale electronic and electromechanical sys- tems. PTs and EMTs are compared on the basis of power and energy density, with PTs trending towards higher values of power and energy density, comparatively, indicating their suitability for small-scale systems. Among PT topologies, bulk disc-type PTs, operating in their fundamental radial extension mode, and free-free beam PTs, operating in their fundamental length extensional mode, are good can- didates for microfabrication and are considered here. Analytical modeling based on the Extended Hamilton Method is used to predict device performance and integrate mechanical tethering as a boundary condition. This model differs from previous PT models in that the electric enthalpy is used to derive constituent equations of motion with Hamilton’s Method, and therefore this approach is also more generally applica- ble to other piezoelectric systems outside of the present work. Prototype devices are microfabricated using a two mask process consisting of traditional photolithography combined with micropowder blasting, and are tested with various output electri- cal loads. 4mm diameter tethered disc PTs on the order of .002cm

3 , two orders smaller than the bulk PT literature, had the followingperformance: a prototype with electrode area ratio (input area / output area) = 1 had peak gain of 2.3 (± 0.1), efficiency of 33 (± 0.1)% and output power density of 51.3 (± 4.0)W cm

-3 (for output power of80 (± 6)mW) at 1M? load, for an input voltage range of 3V-6V (± one standard deviation). The gain results are similar to those of several much larger bulk devices in the literature, but the efficiencies of the present devices are lower. Rectangular topology, free-free beam devices were also microfabricated across 3 or- ders of scale by volume, with the smallest device on the order of .00002cm

3 . These devices exhibited higher quality factorsand efficiencies, in some cases, compared to circular devices, but lower peak gain (by roughly 1/2 ). Limitations of the microfab- rication process are determined, and future work is proposed. Overall, the devices fabricated in the present work show promise for integration into small-scale engi- neered systems, but improvements can be made in efficiency, and potentially voltage gain, depending on the application

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Mehregany, Mehran. "Microfabricated silicon electric mechanisms". Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/14042.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1990.
Includes bibliographical references (leaves 151-156).
by Mehran Mehregany.
Ph.D.

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Griffith, Alun Wyn. "Applications of microfabrication in biosensor technology". Thesis, University of Glasgow, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361768.

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Libri sul tema "Microfabricatin"

Franssila, Sami. Introduction to Microfabrication. Chichester, UK: John Wiley & Sons, Ltd, 2010. http://dx.doi.org/10.1002/9781119990413.

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Sugioka, Koji, Michel Meunier e Alberto Piqué, a cura di. Laser Precision Microfabrication. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-10523-4.

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Chakraborty, Suman, a cura di. Microfluidics and Microfabrication. Boston, MA: Springer US, 2010. http://dx.doi.org/10.1007/978-1-4419-1543-6.

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Michel, Meunier, Piqué Alberto e SpringerLink (Online service), a cura di. Laser Precision Microfabrication. Berlin, Heidelberg: Springer-Verlag Berlin Heidelberg, 2010.

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Narayanan, Sundararajan, a cura di. Microfabrication for microfluidics. Boston: Artech House, 2010.

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Franssila, Sami. Introduction to Microfabrication. New York: John Wiley & Sons, Ltd., 2005.

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Chakraborty, Suman. Microfluidics and Microfabrication. Boston, MA: Springer Science+Business Media, LLC, 2010.

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J, Jackson Mark, a cura di. Microfabrication and nanomanufacturing. Boca Raton, FL: Taylor & Francis, 2005.

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Kordal, Richard, Arthur Usmani e Wai Tak Law, a cura di. Microfabricated Sensors. Washington, DC: American Chemical Society, 2002. http://dx.doi.org/10.1021/bk-2002-0815.

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Nassar, Raja. Modelling of Microfabrication Systems. Berlin, Heidelberg: Springer Berlin Heidelberg, 2003.

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Capitoli di libri sul tema "Microfabricatin"

Adams, Thomas M., e Richard A. Layton. "Microfabrication laboratories". In Introductory MEMS, 371–403. Boston, MA: Springer US, 2009. http://dx.doi.org/10.1007/978-0-387-09511-0_13.

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Leitão, Diana C., José Pedro Amaral, Susana Cardoso e Càndid Reig. "Microfabrication Techniques". In Giant Magnetoresistance (GMR) Sensors, 31–45. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-37172-1_2.

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Shoji, Satoru, e Kyoko Masui. "Nano-/Microfabrication". In Encyclopedia of Polymeric Nanomaterials, 1–7. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-36199-9_108-2.

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Joye, Colin D., Alan M. Cook e Diana Gamzina. "Microfabrication Technologies". In Advances in Terahertz Source Technologies, 701–39. New York: Jenny Stanford Publishing, 2024. http://dx.doi.org/10.1201/9781003459675-26.

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Johnstone, Robert W., e M. Parameswaran. "Microfabrication Processes". In An Introduction to Surface-Micromachining, 9–28. Boston, MA: Springer US, 2004. http://dx.doi.org/10.1007/978-1-4020-8021-0_2.

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Shoji, Satoru, e Kyoko Masui. "Nano-/Microfabrication". In Encyclopedia of Polymeric Nanomaterials, 1311–17. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-642-29648-2_108.

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Ono, Takahito, e Masayoshi Esashi. "Microfabricated Probe Technology". In Encyclopedia of Nanotechnology, 2167–78. Dordrecht: Springer Netherlands, 2016. http://dx.doi.org/10.1007/978-94-017-9780-1_247.

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Juarez-Martinez, Gabriela, Alessandro Chiolerio, Paolo Allia, Martino Poggio, Christian L. Degen, Li Zhang, Bradley J. Nelson et al. "Microfabricated Probe Technology". In Encyclopedia of Nanotechnology, 1406–15. Dordrecht: Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-90-481-9751-4_247.

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Baborowski, J. "Microfabrication of Piezoelectric MEMS". In Electroceramic-Based MEMS, 325–59. Boston, MA: Springer US, 2005. http://dx.doi.org/10.1007/0-387-23319-9_13.

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Qin, Dong, Younan Xia, John A. Rogers, Rebecca J. Jackman, Xiao-Mei Zhao e George M. Whitesides. "Microfabrication, Microstructures and Microsystems". In Topics in Current Chemistry, 1–20. Berlin, Heidelberg: Springer Berlin Heidelberg, 1998. http://dx.doi.org/10.1007/3-540-69544-3_1.

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Atti di convegni sul tema "Microfabricatin"

Levitan, Jeremy A., Dan Good, Michael J. Sinclair e Joseph M. Jacobson. "Creation of Nanometer-Sized Features in Polysilicon Using Fusing". In ASME 2001 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/imece2001/mems-23858.

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Abstract Current microfabrication systems can achieve resolutions of approximately 0.1μm. We present physical methods for creating structures with length scales and characteristic dimensions significantly below current fabrication resolutions. These structures, themselves fabricated in conventional, gross-resolution (greater than 2μm) semiconductor facilities, undergo structural change to create features below the lithography limits of the fabrication process. These devices — dog-boned microfabricated polysilicon fuses — are heated just below melting, and a small perturbation current heats a narrow, necked region of the beam, resulting in fusing. Infrastructure has already been constructed to create gross-resolution structures in microfabrication. Novel processes and mechanisms are needed to utilize these resolutions and create structures capable of addressing biological systems, functioning quantum mechanically, use single electrons, or require extreme speeds.

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Park, Daniel S., Saade Bou-Mikael, Sean King, Karsten E. Thompson, Clinton S. Willson e Dimitris E. Nikitopoulos. "Design and Fabrication of Rock-Based Micromodel". In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-88501.

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A rock-based micromodel was designed using depth averaging with Boise rock digital images obtained from the X-ray micro-computed tomography. Design optimization of 2.5D micromodels was carried out using computational fluid dynamics (CFD) simulations through error analysis of dynamic flow parameters (velocities and permeability), which showed the close dynamic flow match between the actual 3D rock and the optimized 2.5D micromodel. Multiple numbers of polymer micromodels were microfabricated via micromilling of a brass mold insert and hot embossing in polymethylmethacrylate (PMMA). The design optimization and the replication-based microfabrication processes enabled the realistic pore geometry generation, which conforms to the pore dimensions of an actual rock sample but with coarser features in a polymer microfluidic platform. The microfabricated PMMA micromodel was used for fluidic characterization with nanoparticles to compare the flow patterns between the designed micromodel and the microfabricated micromodel. Particle motion paths observed in the particle experiments showed the consistent similarity of stream-traces from the CFD simulations of the designed 2.5D micromodel. Further fluidic investigation on the 2.5D rock-based micromodels will provide better understanding on fluid transport mechanism in porous media.

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Kandra, Deepak, e Ram V. Devireddy. "On the Possible Application of a Microscale Thermocouple to Measure Intercellular Ice Formation in Cells Embedded in an Extracellular Matrix". In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-60728.

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To optimize a freezing protocol for tissue systems, knowledge of intercellular ice formation and water transport is essential. Water transport during freezing can be measured using low temperature microscopy technique [1] and/or by differential scanning calorimetry method [2]. To study the formation of intracellular ice in cells embedded in an extracellular matrix we propose to design and develop an array of microscale thermocouples using microfabrication techniques [3]. The microfabricated thermocouples will be required to accurately measure the small temperature fluctuations in an embedded cell due to the formation of intracellular ice.

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Demiri, S., e S. Boedo. "Clearance Effects on the Impact Behavior of Large Aspect Ratio Silicon Journal Microbearings". In STLE/ASME 2010 International Joint Tribology Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ijtc2010-41189.

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This paper investigates the effect of bearing clearance on the impact behavior of microfabricated silicon journal bearings. The design of a novel test apparatus to assess microbearing wear behavior is presented. Microbearing designs, microfabrication processes, and metrology characterization techniques are discussed. A dynamic impact model of the bearing system based on classical impulse-momentum relations is formulated in order to assess the effect of clearance on rotor speed. Coefficient of restitution values obtained over the range of kinematically allowable radial clearance specifications are found to agree well with previously published results for polysilicon microstructures.

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Carretero, J. A., e K. S. Breuer. "Measurement and Modeling of the Flow Characteristics of Micro Disc Valves". In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-1120.

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Abstract The head losses in microfluidic systems such as micropumps are dominated by losses in microvalves, where microfabrication constraints limit significantly possible microvalve designs. This makes them quite different from conventional valves. In particular, flow characteristics in the laminar and low-Reynolds turbulent regimes are not understood clearly, and detailed information about the flow losses is lacking. This paper addresses this issue by using a scaled-up (10:1) valve experiment to measure pressure losses in typical microfabricated valve geometries. The macroscale model is fully instrumented and discharge coefficients and sensitivities to stroke, seat width and Reynolds number are presented.

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Hsu, C. P., N. E. Jewell-Larsen, A. C. Rollins, I. A. Krichtafovitch, S. W. Montgomery, J. T. Dibene e A. V. Mamishev. "Miniaturization of Electrostatic Fluid Accelerators". In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-13990.

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Existing thermal management methods for electronics do not meet technology needs and remain a major bottleneck in the evolution of computing, sensing, and information technology. The decreasing size of microelectronics components and the resulting increasing thermal output density require novel cooling solutions. Electrohydrodynamic ionic wind pumps, also known as electrostatic fluid accelerators (EFA), have the potential of becoming a critical element of electronic thermal management solutions. In order to take full advantage of EFA-based thermal management, it is essential to miniaturize EFA technology. This paper demonstrates the successful operation of a meso-scale microfabricated silicon EFA. A cantilever structure fabricated in bulk silicon with a radius of tip curvature of 25 μm is used as the corona electrode. The device was fabricated using a Deep Reactive Ion Etching (DRIE) microfabrication process. Forced convection cooling is demonstrated using infrared imaging, showing a 25°C surface temperature reduction over an actively heated substrate. The fabrication and test results of a meso-scale microfabricated EFA are presented in this paper.

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Wang, Yaqiang, e Massood Tabib-Azar. "Fabrication and Characterization of Evanescent Microwave Probes Compatible With Atomic Force Microscope for Scanning Near-Field Microscopy". In ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-33291.

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The design and microfabrication of silicon co-axial evanescent microwave probes (EMP) compatible with atomic force microscope (AFM) imaging was discussed. Scanning EMP (SEMP) imaging is suitable for nondestructive surface and subsurface characterization of materials over a wide frequency range-between 0.1 GHz and 140 GHz. The microfabricated EMP consists of a silicon V-shaped cantilever beam, a co-axial tip, and aluminum co-planar waveguides. The coaxial tip has an apex radius of ∼80 Å. The tip itself is oxidation-sharpened heavily-doped silicon surrounded by an oxide layer that acts as insulator and covered with an aluminum co-axial layer. The tip apex is electrically connected to a strip of aluminum that forms the active part of the waveguide. The design and microfabrication procedure are described. Mechanical and electrical characterizations are discussed. Contact mode and SEMP surface measurement results are reported. The first ever simultaneous contact AFM and scanning near-field microwave microscopy (SNMM) surface imaging are presented. Using the microwave measurement along with the AFM imaging opens up a new window to see inside the materials and sets the stage for hyperspectral imaging of organelles of biological objects as well as electronic devices and structural materials.

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Ko, Jong Soo, Young-Ho Cho, Byung Man Kwak e Kwanhum Park. "Design and Fabrication of Piezoresistive Cantilever Microaccelerometer Arrays With a Symmetrically Bonded Proof-Mass". In ASME 1998 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/imece1998-1267.

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Abstract This paper presents the production-oriented design and microfabrication process of a piezoresistive cantilever-beam microaccelerometer with a symmetrically bonded proof-mass. The symmetrically bonded proof-mass structure is devised not only for improving the production yield, but also for reducing the transverse sensitivity of the accelerometer. The accelerometers are batch fabricated in arrays, from which individual devices are obtained by wafer sawing process. The microfabricated accelerometer shows a resonant frequency of 2.15kHz and a sensitivity of 34μV/g/V within a nonlinearity of 2% over ±30g range at 100Hz. The structure and fabrication processes of the present accelerometer provide practical and effective means for the mass production of accelerometers with high reproducibility.

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Shao, Zhanjie, Carolyn L. Ren e Gerry Schneider. "Control of Laminar Flow and Mass Transport in Crossing Linked Microchannels for Micro Fabrication". In ASME 3rd International Conference on Microchannels and Minichannels. ASMEDC, 2005. http://dx.doi.org/10.1115/icmm2005-75021.

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There has been tremendous interest in developing micro technologies towards the integration and automation of Biochips or Lab-on-a-Chip devices due to their wide range of applications in environmental, chemical and biomedical engineering fields. The laminar flow nature in microfluidic devices offers opportunities to microfabricate the desired structures inside microchannels and pattern culturing medium inside microchannels. However, no analysis tools are available to provide optimized configurations for control the flow for microfabrication. Therefore, the goal of this study is to develop a numerical model to study transport phenomena in a cross-linked microchannels aiming to explore an optimized configuration for the microfabrication of specific desired features inside microchannel networks through investigating the effects of controlling parameters on the multistream flow. In this study, electroosmotic flow with induced pressure-driven flow will be employed. This model consists of a set of equations describing the applied potential field, flow field and concentration field in such geometries. The effects of various operational parameters are investigated based on the simultaneous solution to this model, to explore optimized configurations for flow and mass transport control in crossing linked microchannels.

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Dowling, Karen M., Ateeq J. Suria, Yoonjin Won, Ashwin Shankar, Hyoungsoon Lee, Mehdi Asheghi, Kenneth E. Goodson e Debbie G. Senesky. "Inductive Coupled Plasma Etching of High Aspect Ratio Silicon Carbide Microchannels for Localized Cooling". In ASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems collocated with the ASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/ipack2015-48409.

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High aspect ratio microchannels using high thermal conductivity materials such as silicon carbide (SiC) have recently been explored to locally cool micro-scale power electronics that are prone to on-chip hot spot generation. Analytical and finite element modeling shows that SiC-based microchannels used for localized cooling should have high aspect ratio features (above 8:1) to obtain heat transfer coefficients (300 to 600 kW/m2·K) required to obtain gallium nitride (GaN) device channel temperatures below 100°C. This work presents experimental results of microfabricating high aspect ratio microchannels in a 4H-SiC substrate using inductively coupled plasma (ICP) etching. Depths of 90 μm and 80 μm were achieved with a 5:1 and 12:1 aspect ratio, respectively. This microfabrication process will enable the integration of microchannels (backside features) with high-power density devices such as GaN-on-SiC based electronics, as well as other SiC-based microfluidic applications.

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Rapporti di organizzazioni sul tema "Microfabricatin"

Woodard, David W. Microfabrication Technology for Photonics. Fort Belvoir, VA: Defense Technical Information Center, giugno 1990. http://dx.doi.org/10.21236/ada225428.

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Jau, Yuan-Yu. Microfabricated Waveguide Atom Traps. Office of Scientific and Technical Information (OSTI), settembre 2017. http://dx.doi.org/10.2172/1396077.

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Cowan, Benjamin M. Microfabrication of Laser-Driven Accelerator Structures. Office of Scientific and Technical Information (OSTI), aprile 2003. http://dx.doi.org/10.2172/812999.

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James C. Lund. Microfabricated Solid State Neutron Generators. Office of Scientific and Technical Information (OSTI), novembre 2000. http://dx.doi.org/10.2172/791322.

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James C. Lund. Microfabricated Solid State Neutron Generators. Office of Scientific and Technical Information (OSTI), settembre 2001. http://dx.doi.org/10.2172/791324.

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Bauer, Todd, Adam Jones, Tony Lentine, John Mudrick, Murat Okandan e Arun Rodrigues. Trends in Microfabrication Capabilities & Device Architectures. Office of Scientific and Technical Information (OSTI), giugno 2015. http://dx.doi.org/10.2172/1184366.

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Bauer, Todd, Adam Jones, Anthony L. Lentine, John Mudrick, Murat Okandan e Arun F. Rodrigues. Trends in Microfabrication Capabilities & Device Architectures. Office of Scientific and Technical Information (OSTI), giugno 2015. http://dx.doi.org/10.2172/1192538.

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Joye, Colin D., Alan M. Cook, Jeffrey P. Calame, David K. Abe, Khanh T. Nguyen, Edward L. Wright, Jeremy M. Hanna, Igor A. Chernyavskiy e Baruch Levush. Microfabrication Techniques for Millimeter Wave Vacuum Electronics. Fort Belvoir, VA: Defense Technical Information Center, gennaio 2015. http://dx.doi.org/10.21236/ad1004171.

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Mastrangelo, C. H. Microfabrication Techniques for Plastic Microelectromechanical Systems (MEMS). Fort Belvoir, VA: Defense Technical Information Center, luglio 2003. http://dx.doi.org/10.21236/ada420836.

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Lawandy, N. M. Laser Microfabrication in Glasses: Mechanisms and Applications. Fort Belvoir, VA: Defense Technical Information Center, marzo 1997. http://dx.doi.org/10.21236/ada376443.

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