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Topology Optimized Design, Microfabrication and Characterization of Electro-Thermally Driven Microgripper

RUBIO, Wilfredo M.; Silva, Emilio Carlos Nelli; BORDATCHEV, Evgueni V.; ZEMAN, Marco J. F.
Fonte: SAGE PUBLICATIONS LTD Publicador: SAGE PUBLICATIONS LTD
Tipo: Artigo de Revista Científica
ENG
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This article presents a systematic and logical study of the topology optimized design, microfabrication, and static/dynamic performance characterization of an electro-thermo-mechanical microgripper. The microgripper is designed using a topology optimization algorithm based on a spatial filtering technique and considering different penalization coefficients for different material properties during the optimization cycle. The microgripper design has a symmetric monolithic 2D structure which consists of a complex combination of rigid links integrating both the actuating and gripping mechanisms. The numerical simulation is performed by studying the effects of convective heat transfer, thermal boundary conditions at the fixed anchors, and microgripper performance considering temperature-dependent and independent material properties. The microgripper is fabricated from a 25 mm thick nickel foil using laser microfabrication technology and its static/dynamic performance is experimentally evaluated. The static and dynamic electro-mechanical characteristics are analyzed as step response functions with respect to tweezing/actuating displacements, applied current/power, and actual electric resistance. A microgripper prototype having overall dimensions of 1mm (L) X 2.5mm (W) is able to deliver the maximum tweezing and actuating displacements of 25.5 mm and 33.2 mm along X and Y axes...

Two-photon absorption spectrum of the photoinitiator Lucirin TPO-L

MENDONCA, Cleber Renato; CORREA, D. S.; BALDACCHINI, T.; TAYALIA, P.; MAZUR, E.
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
ENG
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Two-photon absorption induced polymerization provides a powerful method for the fabrication of intricate three-dimensional microstructures. Recently, Lucirin TPO-L was shown to be a photoinitiator with several advantageous properties for two-photon induced polymerization. Here we measure the two-photon absorption cross-section spectrum of Lucirin TPO-L, which presents a maximum of 1.2 GM at 610 nm. Despite its small two-photon absorption cross-section, it is possible to fabricate excellent microstructures by two-photon polymerization due to the high polymerization quantum yield of Lucirin TPO-L. These results indicate that optimization of the two-photon absorption cross-section is not the only material parameter to be considered when searching for new photoinitiators for microfabrication via two-photon absorption.

Fabrication and integration of planar electrodes for contactless conductivity detection on polyester-toner electrophoresis microchips

COLTRO, Wendell Karlos Tomazelli; SILVA, Jose Alberto Fracassi da; CARRILHO, Emanuel
Fonte: WILEY-V C H VERLAG GMBH Publicador: WILEY-V C H VERLAG GMBH
Tipo: Artigo de Revista Científica
ENG
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In this report, we describe the microfabrication and integration of planar electrodes for contactless conductivity detection on polyester-toner (PT) electrophoresis microchips using toner masks. Planar electrodes were fabricated by three simple steps: (i) drawing and laser-printing the electrode geometry on polyester films, (ii) sputtering deposition onto substrates, and (iii) removal of toner layer by a lift-off process. The polyester film with anchored electrodes was integrated to PT electrophoresis microchannels by lamination at 120 degrees C in less than 1 min. The electrodes were designed in an antiparallel configuration with 750 mu m width and 750 gm gap between them. The best results were recorded with a frequency of 400 kHz and 10 V-PP using a sinusoidal wave. The analytical performance of the proposed microchip was evaluated by electrophoretic separation of potassium, sodium and lithium in 150 mu m wide x 6 mu m deep microchannels. Under an electric field of 250 V/cm the analytes were successfully separated in less than 90 s with efficiencies ranging from 7000 to 13 000 plates. The detection limits (S/N = 3) found for K+, Na+, and Li+ were 3.1, 4.3, and 7.2 mu mol/L, respectively. Besides the low-cost and instrumental simplicity...

Novas tecnologias para fabricação de microsistemas analíticos e detecção eletroquímica; New technologies for the fabrication of microluidic devices with electrochemical detection

Piccin, Evandro
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 11/04/2008 PT
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Este trabalho de doutorado apresenta o desenvolvimento de novas tecnologias para fabricação de microsistemas analíticos e detecção eletroquímica. Primeiramente, a poliuretana elastomérica, derivada de uma fonte renovável, o óleo de mamona, foi utilizada como um novo e alternativo material para fabricação de microdispositivos. Foram avaliadas as características físicas dos microcanais formados por moldagem, a compatibilidade química com solventes e eletrólitos, as características de superfície através dos ângulos de contato, o EOF em diferentes pHs e a performance analítica em experimentos de eletroforese com detecção eletroquímica. A segunda parte do trabalho apresenta o desenvolvimento de um método para a determinação simultânea de azo-corantes comumente usados na indústria alimentícia. Amaranto, amarelo crepúsculo FCF, amarelo sólido AB, ponceu 4R e vermelho 2G, foram separados e quantificados através de eletroforese em microdispositivos com detecção eletroquímica. Foram estudados e otimizados vários parâmetros que influenciaram a separação eletroforética e detecção eletroquímica, em experimentos realizados usando microdispositivos de vidro e eletrodo de trabalho de carbono vítreo. Finalmente...

Absorção de multi-fótons em polímeros e resinas poliméricas: espectroscopia não linear e microfabricação; Multi-photon absorption in polymers and polymeric resins: nonlinear spectroscopy and microfabrication

Corrêa, Daniel Souza
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 12/02/2009 PT
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Nesta tese, estudamos o processo de absorção multifotônica em polímeros e resinas poliméricas, abordando tanto aspectos fundamentais quanto aplicados. Com relação aos aspectos fundamentais, estudamos processos de absorção multifotônica (absorção de dois, três e quatro fótons) no polímero conjugado MEH-PPV (poly(2-methoxy-5-(2´-ethylhexyloxy)-1,4- phenylenevinylene)), utilizando a técnica de Varredura-Z com pulsos ultracurtos. Através desta técnica, determinamos o espectro da absorção de dois, três e quatro fótons do MEHPPV. As seções de choque de absorção de multi-fótons correspondentes a cada processo foram determinadas através do ajuste das curvas experimentais com um conjunto de equações desenvolvidas neste trabalho. Os resultados obtidos permitiram traçar relações entre os espectros não lineares e os níveis de energia do polímero. Na vertente mais aplicada do projeto, estudamos a fotopolimerização de resinas acrílicas através do processo de absorção de dois fótons. Devido ao confinamento espacial da polimerização, graças à absorção de dois fótons, este método permite a confecção de micro-estruturas complexas para diversas aplicações tecnológicas. Além da fabricação de microestruturas convencionais não dopadas...

Microfabricação por fotopolimerização via absorção de dois fótons; Two-photon absorption photopolymerization microfabrication

Gomes, Vinicius Tribuzi Rodrigues Pinheiro
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 10/02/2009 PT
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Neste trabalho usamos pulsos de femtossegundos na fabricação de estruturas poliméricas em escala microscópica, através da técnica de fotopolimerização via absorção de dois fótons. Graças ao confinamento espacial da polimerização, resultante do processo de absorção de dois fótons, este método permite a fabricação de microestruturas tridimensionais complexas, com alta resolução, visando diversas aplicações tecnológicas, de fotônica até biologia. Inicialmente, desenvolvemos a técnica de fotopolimerização via absorção de dois fótons, desde a implantação da montagem óptica até a confecção dos sistemas de movimentação e controle do posicionamento do feixe laser. Através da fabricação e caracterização de microestruturas, produzidas em resinas acrílicas, o sistema foi aperfeiçoado permitindo a produção de microestruturas da pordem de 30um com razoável resolução espacial. Uma vez que a maior parte as microestruturas reportadas na literatura são elementos passivos, ou seja, suas propriedades ópticas não podem ser controladas por meios externos, numa segunda etapa deste projeto produzimos microestruturas opticamente ativas. Neste caso, a microfabricação foi feita em resinas acrílicas dopadas Rodamina B...

Microelectrode arrays fabricated using a novel hybrid microfabrication method

Merlo, Mark W.; Snyder, Russell L.; Middlebrooks, John C.; Bachman, Mark
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /02/2012 EN
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We present novel hybrid microfabrication methods for microelectrode arrays that combine microwire assembly, microelectromechanical systems (MEMS) manufacturing techniques and precision tool-based micromachining. This combination enables hybrid microfabrication to produce complex geometries and structures, increase material selection, and improve integration. A 32-channel shank microelectrode array was fabricated to highlight the hybrid microfabrication techniques. The electrode shank was 130 μm at its narrowest, had a 127 μm thickness and had iridium oxide electrode sites that were 25 μm in diameter with 150 μm spacing. Techniques used to fabricate this electrode include microassembly of insulated gold wires into a micromold, micromolding the microelectrode shank, post molding machining, sacrificial release of the microelectrode and electrodeposition of iridium oxide onto the microelectrode sites. Electrode site position accuracy was shown to have a standard deviation of less than 4 μm. Acute in vivo recordings with the 32-channel shank microelectrode array demonstrated comparable performance to that obtained with commercial microelectrode arrays . This new approach to microelectrode array fabrication will enable new microelectrodes...

Microfabrication and Nanotechnology in Stent Design

Martinez, Adam W.; Chaikof, Elliot L.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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Intravascular stents were first introduced in the 1980s as an adjunct to primary angioplasty for management of early complications, including arterial dissection, or treatment of an inadequate technical outcome due to early elastic recoil of the atherosclerotic lesion. Despite the beneficial effects of stenting, persistent high rates of restenosis motivated the design of drug eluting stents for delivery of agents to limit the proliferative and other inflammatory responses within the vascular wall that contribute to the development of a restenotic lesion. These strategies have yielded a significant reduction in the incidence of restenosis, but challenges remain, including incomplete repair of the endothelium at the site of vascular wall injury that may be associated with a late risk of thrombosis. A failure of vessel wall healing has been attributed to primarily to the use of polymeric stent coatings, but the effects of the eluted drug and other material properties or design features of the stent cannot be excluded. Improvements in stent microfabrication, as well as the introduction of alternative materials may help to address those limitations that inhibit stent performance. This review describes the application of novel microfabrication processes and the evolution of new nanotechnologies that hold significant promise in eliminating existing shortcomings of current stent platforms.

Microfabrication Technologies for Oral Drug Delivery

Sant, Shilpa; Tao, Sarah L.; Fisher, Omar; Xu, Qiaobing; Peppas, Nicholas A.; Khademhosseini, Ali
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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Micro-/nanoscale technologies such as lithographic techniques and microfluidics offer promising avenues to revolutionalize the fields of tissue engineering, drug discovery, diagnostics and personalized medicine. Microfabrication techniques are being explored for drug delivery applications due to their ability to combine several features such as precise shape and size into a single drug delivery vehicle. They also offer to create unique asymmetrical features incorporated into single or multiple reservoir systems maximizing contact area with the intestinal lining. Combined with intelligent materials, such microfabricated platforms can be designed to be bioadhesive and stimuli-responsive. Apart from drug delivery devices, microfabrication technologies offer exciting opportunities to create biomimetic gastrointestinal tract models incorporating physiological cell types, flow patterns and brush-border like structures. Here we review the recent developments in this field with a focus on the applications of microfabrication in the development of oral drug delivery devices and biomimetic gastrointestinal tract models that can be used to evaluate the drug delivery efficacy.

Non-linear mechanical behavior of polydimethylsiloxane (PDMS): application to the manufacture of microfluidic devices

Huang, Regina; Lele, Suvrat P.; Anand, Lallit
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
Tipo: Artigo de Revista Científica Formato: 49625 bytes; application/pdf
EN_US
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Soft-lithography is a low-cost and convenient microfabrication technique that is becoming increasingly popular in the manufacture of microfluidic devices. A typical elastomer used in soft-lithography is polydimethylsiloxane (PDMS), an organic polymer that is commercially available, inexpensive, optically transparent, permeable to gases, and nontoxic. For soft-lithography to become a viable microfabrication technique for the commercial manufacture of microfluidic devices, several issues concerning the mechanical behavior of this material must be considered and addressed. We are currently working on the following materials-related issues that are critical to the development of this process for mass production:
•Multilayer microfluidic devices are made by layering thin films having alternating ratios of monomer to curing agent, in order to facilitate bonding between the layers. Common mixing ratios of monomer to curing agent are 5:1, 10:1, and 20:1. Characterization of the mechanical behavior of these materials with different compositions is necessary in the design of these devices. We have conducted uniaxial tension tests at the macroscale and found that the monomer-to-curing agent ratio contributes significantly to the non-linear stress-strain behavior of PDMS (see adjoining figure). We are working on uniaxial tension tests on microscale specimens which are approximately 10 µm thick and have a gauge width of 1 mm; this smaller scale is representative of actual dimensions in microfluidic devices.
•The fabrication of microfluidic devices involves curing the mixture of PDMS monomer and curing agent on a mold. Currently...

Process development of silicon-silicon carbide hybrid structures for micro-engines (January 2002)

Choi, D.; Shinavski, R.J.; Spearing, S. Mark
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
Tipo: Artigo de Revista Científica Formato: 1354372 bytes; application/pdf
EN_US
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MEMS-based gas turbine engines are currently under development at MIT for use as a button-sized portable power generator or micro-aircraft propulsion sources. Power densities expected for the micro-engines require very high rotor peripheral speeds of 300-600m/s and high combustion gas temperatures of 1300-1700K. These harsh requirements for the engine operation induce very high stress levels in the engine structure, and thus call for qualified refractory materials with high strength. Silicon carbide (SiC) has been chosen as the most promising material for use due to its high strength and chemical inertness at elevated temperatures. However, the state-of-the art microfabrication techniques for single-crystal SiC are not yet mature enough to achieve the required level of high precision of micro-engine components. To circumvent this limitation and to take advantage of the well-established precise silicon microfabrication technologies, silicon-silicon carbide hybrid turbine structures are being developed using chemical vapor deposition (CVD) of thick SiC (up to ~70µm) on silicon wafers and wafer bonding processes. Residual stress control of thick SiC layers is of critical importance to all the silicon-silicon carbide hybrid structure fabrication steps since a high level of residual stresses causes wafer cracking during the planarization...

Performance-Driven Microfabrication-Oriented Methodology for MEMS Conceptual Design with Application in Microfluidic Device Design

Deng, Y.-M.; Lu, Wen Feng
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
Tipo: Artigo de Revista Científica Formato: 205852 bytes; application/pdf
EN
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Performance and manufacturability are two important issues that must be taken into account during MEMS design. Existing MEMS design models or systems follow a process-driven design paradigm, that is, design starts from the specification of process sequence or the customization of foundry-ready process template. There has been essentially no methodology or model that supports generic, high-level design synthesis for MEMS conceptual design. As a result, there lacks a basis for specifying the initial process sequences. To address this problem, this paper proposes a performance-driven, microfabrication-oriented methodology for MEMS conceptual design. A unified behaviour representation method is proposed which incorporates information of both physical interactions and chemical/biological/other reactions. Based on this method, a behavioural process based design synthesis model is proposed, which exploits multidisciplinary phenomena for design solutions, including both the structural components and their configuration for the MEMS device, as well as the necessary substances for the chemical/biological/other reactions. The model supports both forward and backward synthetic search for suitable phenomena. To ensure manufacturability, a strategy of using microfabrication-oriented phenomena as design knowledge is proposed...

Novel multiphase chemical reaction systems enabled by microfabrication technology

Losey, Matthew W
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 251 leaves; 23228967 bytes; 23228719 bytes; application/pdf; application/pdf
ENG
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Advances in MEMS (micro-electromechanical systems) have enabled some of the "Lab-on-a-Chip" technologies and microfluidics that are pervasive in many of the current developments in analytical chemistry and molecular biology. Coinciding with this effort in micro-analytics has been research in chemical process miniaturization -- reducing the characteristic length scale of the unit operation to improve heat and mass transfer, and ultimately process performance. My research has involved the design and fabrication of novel chemical reaction systems using MEMS and microfabrication methods (photolithography, deep-reactive-ion etching, thin-film growth and deposition, and multiple wafer bonding). Miniature chemical systems provide the opportunity for distributed, on-demand manufacturing, which would eliminate the hazards of transportation and storage of toxic or hazardous chemical intermediates. Reactions that are particularly suitable for miniaturized chemical systems are those that are fast and involve toxic intermediates: the controlled synthesis of phosgene is such a reaction and has been demonstrated in a microfabricated packed bed reactor. Owing to the high surface-to-volume ratios, micro chemical systems also have the potential to make improvements in process performance through enhanced heat and mass transfer.; (cont.) Heterogeneously catalyzed gas-liquid reactions have been performed in the microfabricated reactors and have been shown to have mass transfer coefficients several orders of magnitude larger than their industrial-scale counterparts. Multiphase reactions are often hindered by mass-transfer limitations owing to the difficulty in transporting the gaseous reactant through the liquid to the catalytic surface. The microchemical device has been designed to increase the interfacial gas-liquid contacting area by promoting dispersion and preventing coalescence. Microfabrication allows the design of reactors with complicated fluidic distribution networks...

Simulation de profils de gravure et de dépôt à l’échelle du motif pour l’étude des procédés de microfabrication utilisant une source plasma de haute densité à basse pression

Laberge, Michael
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
FR
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En lien avec l’avancée rapide de la réduction de la taille des motifs en microfabrication, des processus physiques négligeables à plus grande échelle deviennent dominants lorsque cette taille s’approche de l’échelle nanométrique. L’identification et une meilleure compréhension de ces différents processus sont essentielles pour améliorer le contrôle des procédés et poursuivre la «nanométrisation» des composantes électroniques. Un simulateur cellulaire à l’échelle du motif en deux dimensions s’appuyant sur les méthodes Monte-Carlo a été développé pour étudier l’évolution du profil lors de procédés de microfabrication. Le domaine de gravure est discrétisé en cellules carrées représentant la géométrie initiale du système masque-substrat. On insère les particules neutres et ioniques à l’interface du domaine de simulation en prenant compte des fonctions de distribution en énergie et en angle respectives de chacune des espèces. Le transport des particules est effectué jusqu’à la surface en tenant compte des probabilités de réflexion des ions énergétiques sur les parois ou de la réémission des particules neutres. Le modèle d’interaction particule-surface tient compte des différents mécanismes de gravure sèche telle que la pulvérisation...

Laser-based microfabrication for cell adhesion and migration

Miller, Jordan S.
Fonte: Universidade Rice Publicador: Universidade Rice
ENG
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Mammalian cell adhesion and migration impact a multitude of cellular behaviors and tissue remodeling processes. Over the past several decades, investigators have methodically improved in vitro systems as mimics of the extracellular microenvironment to study these biologic phenomena. Experiments have progressed from early studies on bifunctional inorganic surfaces to those with purified adhesive proteins against an organic, non-adhesive background. Recently, subcellular geometric patterns of adhesive proteins have proven useful to restrict and direct focal contact formation, cell survival, lamellopodia extension, and the maturation of "supermature" focal contacts. The vast majority of recent studies have involved the construction of hydrophobic patches with adsorbed fibronectin as the adhesive constraint of choice. However, the extracellular matrix (ECM) in which cells operate is a complex and diverse environment where numerous signals interact with a cell simultaneously; signals that the cell must integrate and that directly impact these processes. Microfabrication methods to approximate the extracellular milieu have significant limitations in their potential to be extended to pattern multiple bioactive ligands with high precision. Current techniques require multi-step processes which lose feature fidelity at every pattern transfer step...

The development and characterization of a nickel/metal hydride microbattery for microfluidic applications

FALAHATI, HAMID
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
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Micro Electro Mechanical Systems as well as Microfluidics are versatile technologies which have been evolved due to the advantage of miniaturization over the last decades. However, the majority of microfluidic devices are still powered by macroscale power supplies. Here, interconnection problems, unwanted electronic interactions (noise), and difficulties in controlling the power delivered are some of the problems which can arise. One possible approach to ease such difficulties is through the use of integrated (embedded) power sources. This thesis is focused on the development and characterization of a nickel/metal hydride microbattery on a glass substrate which can be easily integrated during the regular microfabrication process of the microfluidic device. Glass or glass-like materials, such as silicon dioxide, are often used as substrates for microfluidic chips. Hence, we pursue a two-dimensional approach in that we fabricate thin films of electroactive materials on glass wafers using microfabrication techniques which are common in semiconductor (electronics) industries. A tailored polymeric layer is placed between the two electrodes to serve as an electrolyte reservoir and electrode separator in a sandwich-like structure which mimics a typical microfluidic chip design. The microfabricated electrodes are investigated in terms of material characterization and electrochemical performance. In detail...

Polymer microfluidic devices: an overview of fabrication methods

Rodrigues, Raquel; Lima, R.; Gomes, Helder; Silva, Adrián
Fonte: Instituto Politécnico de Bragança Publicador: Instituto Politécnico de Bragança
Tipo: Artigo de Revista Científica
ENG
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The amount of applications associated with microfluidic devices is increasing since the introduction of Lab-on-a-chip devices in the 1990s, especially regarding biomedical and clinical fields. However, in order for this technology to leave the fundamental research and become a day-life technology (e.g., as point-of-care testing), it needs to be disposable and reasonably less expensive. Polymers, due to their several advantages, such as easier microfabrication and low-cost, fill these needs. Several methods are reported regarding microfabrication and, thus, the main aim of the present work is to provide an overview of the most relevant microfabrication techniques found in literature employing polymers, clarifying also the main advantages and disadvantages of each technique and especially considering their cost and time-consumption. Moreover, a future outlook of low-cost microfabrication techniques and standard methods is provided.

Microfabrication of Three-Dimensional Structures in Polymer and Glass by Femtosecond Pulses

Juodkazis, Saulius; Kondo, Toshiaki; Mizeikis, Vygantas; Matsuo, Shigeki; Misawa, Hiroaki; Vanagas, Egidijus; Kudryashov, Igor
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 09/05/2002
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We report three-dimensional laser microfabrication, which enables microstructuring of materials on the scale of 0.2-1 micrometers. The two different types of microfabrication demonstrated and discussed in this work are based on holographic recording, and light-induced damage in transparent dielectric materials. Both techniques use nonlinear optical excitation of materials by ultrashort laser pulses (duration < 1 ps).; Comment: This is a proceedings paper of bi-lateral Conf. (Republics of China & Lithuania) on Optoelectronics and Magnetic Materials, Taipei, May 25-26, 2002.}

Microfabrication of Laser-Driven Accelerator Structures

Cowan, Benjamin
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 25/04/2003
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We discuss the potential for using microfabrication techniques for laser-driven accelerator construction. We introduce microfabrication processes in general, and then describe our investigation of a particular trial process. We conclude by considering the issues microfabrication raises for possible future structures.; Comment: 7 pages, 3 figures; Submitted to Tenth Advanced Accelerator Concepts Workshop (AAC 2002), June 23--28, 2002, Mandalay Beach, California (AIP Conference Proceedings)

Microfabrication techniques for trapped ion quantum information processing

Britton, Joe
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 12/08/2010
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Quantum-mechanical principles can be used to process information (QIP). In one approach, linear arrays of trapped, laser cooled ion qubits (two-level quantum systems) are confined in segmented multi-zone electrode structures. The ion trap approach to QIP requires trapping and control of numerous ions in electrode structures with many trapping zones. I investigated microfabrication of structures to trap, transport and couple large numbers of ions. Using 24Mg+ I demonstrated loading and transport between zones in microtraps made of boron doped silicon. This thesis describes the fundamentals of ion trapping, the characteristics of silicon-based traps amenable to QIP work and apparatus to trap ions and characterize traps. Microfabrication instructions appropriate for nonexperts are included. Ion motional heating was measured. <<>> Using MEMs techniques I built a Si micro-mechanical oscillator and demonstrated a method to reduce the kinetic energy of its lowest order mechanical mode via capacitive coupling to a driven radio frequency (RF) oscillator. Cooling resulted from a RF capacitive force, phase shifted relative to the cantilever motion. The technique was demonstrated by cooling the 7 kHz fundamental mode from room temperature to 45 K. <<>> I also discuss an implementation of the semiclassical quantum Fourier transform (QFT) using three beryllium ion qubits. The QFT is a crucial step in a number of quantum algorithms including Shor's algorithm...