Dissertations / Theses on the topic 'Microfabrication'
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1
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.
3
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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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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Duan, Xuefeng 1981. "Microfabrication : using bulk wet etching with TMAH." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97942.
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In November 2002 a Microfabrication Lab was established in the physics department of McGill University to support research in nanoscience and technology. At the same time, I arrived at McGill to begin my graduate study. So I was assigned to do research on microfabrication, especially bulk wet etching of silicon using TetraMethyl Ammonium Hydroxide (TMAH).The content of microfabrication is quite broad, and also very useful in both industry and academic. Since our fab is a newly built one and I had no experience in this area before, this thesis mainly included some basic processes in microfabrication, such as the photolithography, wet etching, reactive ion etching, and soon. Also it compared the wet etching with dry etching. Some results of TMAH wet etching were showed in the thesis, which agreed well with that of the other groups. A simulation program was developed to predict the etching result of TMAH and it appeared to work well. Finally, based on the knowledge and experience acquired, processes in making cantilever and tip structures, which are critical in the scanning probe microscopes, were developed. Silicon oxide cantilevers with length of 100-200 mum, width of 30-50 mum, and thickness of 1 mum were obtained. Pyramid like silicon tips were also fabricated using the wet etching.
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DiBartolomeo, Franklin. "HIGH SPEED CONTINUOUS THERMAL CURING MICROFABRICATION SYSTEM." UKnowledge, 2011. http://uknowledge.uky.edu/gradschool_theses/105.
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Rapid creation of devices with microscale features is a vital step in the commercialization of a wide variety of technologies, such as microfluidics, fuel cells and self-healing materials. The current standard for creating many of these microstructured devices utilizes the inexpensive, flexible material poly-dimethylsiloxane (PDMS) to replicate microstructured molds. This process is inexpensive and fast for small batches of devices, but lacks scalability and the ability to produce large surface-area materials. The novel fabrication process presented in this paper uses a cylindrical mold with microscale surface patterns to cure liquid PDMS prepolymer into continuous microstructured films. Results show that this process can create continuous sheets of micropatterned devices at a rate of 1.9 in2/sec (~1200 mm2/sec), almost an order of magnitude faster than soft lithography, while still retaining submicron patterning accuracy.
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Charlton, Martin David Brian. "Computational design and microfabrication of photonic crystals." Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287304.
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Zoorob, Majd Elias. "Computational design and microfabrication of photonic quasicrystals." Thesis, University of Southampton, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342813.
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Shur, Maiya 1980. "Microfabrication methods for the study of chemotaxis." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/27130.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.Includes bibliographical references (leaves 59-60).
We have developed a system for studying chemotaxis in a microfabricated system. The goal was to develop a system capable of generating spatially and temporally stable concentration gradients of a chemotactic molecule while providing a viable environment for the cell. Numerical models were generated to investigate fluid flow in microchannels for given geometries. Through computational modeling and experimentally-driven iteration of the design, features of the chamber were determined and geometry was established. Prototypes of the system were fabricated using soft lithography and multi-layer soft lithography techniques. Three fluid delivery methods for establishing gradients in the system have been studied: gravity feed system, dual-syringe pump feed system, and integrated individually-controlled peristaltic pump feed system. We were able to create spatially and temporally stable gradients using the dual-syringe feed setup. Two syringes were used to pump a chemokine and a buffer in parallel channels that are connected by a cross-channel and terminated to a single output. Microbeads in the flow were used to confirm the lack of movement in the cross-channel. Human neutrophil viability over the course of several hours and directed cell movement was demonstrated in microchannels.
by Maiya Shur.
S.M.
10
Tu, Yudi. "Photo Processing and Microfabrication of Graphene Oxide." Kyoto University, 2018. http://hdl.handle.net/2433/232039.
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Lund, Jason Matthew. "Advanced Techniques for Carbon Nanotube Templated Microfabrication." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/7769.
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Carbon nanotube templated microfabrication (CNT-M) is a term describing a grouping of processes where carbon nanotubes (CNTs) serve a structural role in the fabrication of a material or device. In its basic form, CNT-M is comprised of two steps: produce a template made from carbon nanotubes and infiltrate the porous template with an additional material. Vertically aligned carbon nanotube (VACNT) templates can be grown to heights ranging from microns to millimeters and lithographically patterned to a desired form. Deposition of an existing thin film material onto a CNT template will coat all template surfaces and can produce a near solid material with dimensions on the millimeter scale with resulting material properties coming primarily from the thin film. Progress within CNT-M falls broadly within one of two categories: control of the CNT template's properties and form, or control of infiltration and new materials.Three-dimensional CNT templates were developed to allow patterned multilayer VACNT structures. In one embodiment, VACNTs were grown below an existing, patterned and capillary-formed VACNT structure by reusing the original catalyst in combination with newly deposited catalyst to create a CNT-based microneedle array on a VACNT support. In another embodiment, VACNTs were mechanically coupled from the initial stages of growth to create a smooth, low porosity surface on which a secondary, patterned CNT forest was grown using standard film deposition and lithographic techniques.A microfabrication compatible thermal barrier was produced using CNTs as a sacrificial template for silicon oxide. The resulting thermal barrier exhibited a thermal conductivity that could be tuned across 2 orders of magnitude based on the degree to which the sacrificial template was removed. Carbon infiltrated carbon nanotubes (CI-CNTs) were produced that exhibited a Young's modulus ranging from 5GPa to 26GPa based on controlled process parameters. Porosity, centroid position, and the second moment of area was calculated from SEM images of CI-CNT structures using an automatic pore identification technique. The porosity results suprisingly show little to no porosity gradient across the width of the structure and a nearly linear increase in porosity from the top to bottom. This work advances the understanding of existing CNT-M processes and demonstrates novel techniques for producing future CNT templates.
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Stillman, Janet Allyn. "Three-dimensional microfabrication with laser-patterned photostructurable glass." Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1779690371&sid=28&Fmt=2&clientId=1564&RQT=309&VName=PQD.
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Cantarella, Giuseppe. "Design, microfabrication and characterisation of Photonic Integrated Circuits." Thesis, University of Strathclyde, 2017. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=28500.
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This doctoral dissertation deals with the design, fabrication and characterization of state-of-the-art Photonic Integrated Circuits (PICs) for non-linear applications. Silicon PICs is a technology mainly used for application in telecommunications and quantum optics. The strong third order non-linearity of silicon makes it also attractive for non-linear PIC design. In FWM applications, SOI technology can be used not only for non-linear generation but also to fabricate photonic filters to remove the residual pump. This thesis deals with three requirements for the realisation of on-chip FWM optical devices, the dual polarisation rejection of the pump on-chip and the integration and stabilisation of the FWM source and optical filter. In this work two of the most used SOI photonic integrated filters, ring resonators and Bragg gratings, are presented. These devices present two different solutions for high extinction(≈ 60 dB) dual polarisation filtering. An integrated structure of non-linear source and filter is presented. The device used for non-linear generation is then monolithically integrated with a novel ring resonators cascade filter technology. FWM experiments were carried out obtaining an on chip pump high dual polarisation extinction of 62 dB with a low insertion loss for the propagating signal and idler of only 1.8 dB.The realisation of a microprocessor feedback loop stabilisation system integrated with SOI non-linear structures is also demonstrated. The system is based on a local thermal heater element on-chip used to stabilise the PICs against thermal refractive index variations. Using this method, a silicon π-phase shifted grating with a cavity Q-factor of 40k is demonstrated to operate over an ambient temperature detuning range of 40 oC and injection wavelength range of 1.5 nm, nearly 3 orders of magnitude greater than the resonant cavity line width. The last part of this work is dedicated to the description of a custom made laser photolitography system for rapid prototyping of PIC designs, a tool designed to overcome the costs of the typical lithography systems and drastically decrease the time required for multiple micro-fabrications. The hardware and the software created for this tool are presented together with the first results on the fabrication of SU-8 Photoresist (SU − 8) on Silicon Dioxide (SiO2) waveguides, bends, Mach Zehnder interferometers and ring resonators.
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Song, Mi Yeon. "Microfabrication of silicon tips for scanning probe microscopy." Thesis, University of Birmingham, 2009. http://etheses.bham.ac.uk//id/eprint/482/.
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This thesis investigates the microfabrication of silicon tips for Scanning Probe Microscopy. First, a microfabrication process was developed to produce silicon tips over 100 um height with a sharp apex of ~10–20 nm. To prevent inadvertent contact between the substrate bearing the tip and the sample being probed, the tip is elevated on a mesa structure. Atomic resolution STM images of graphite are successfully obtained using silicon tips. Subsequently, a co-axial tip was developed for SPELS. SPELS uses an STM tip in field emission mode and then analyses the energy of electrons backscattered. However, the electric field distorts the trajectories of the backscattered electrons. A screened co-axial tip was thus designed; the tip consists of a multilayer Si/Au/HfO\(-2\)/Au structure. The outermost Au layer is grounded. SPELS spectra of graphite were successfully obtained for the first time. Third, a multilayered tip was fabricated for the Scanning Probe Electron AnalyseR.. This approach is a combination of STM with an ultraviolet light source. The designed structure is a multilayered silicon tip consisting of Si/SiO\(_2\)/Au/SiO\(_2\)/Au; the three conducting layers act as an electron collector, retarding field analyser, and grounded shield layer, respectively.
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Hastings, Abel Z. 1973. "Assessing the viability of various metallic microfabrication techniques." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8460.
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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2002.Includes bibliographical references (p. 85-89).
An investigation was completed to assess the viability of a group of metallic microfabrication techniques aimed at the production of microelectromechanical systems (MEMS) This undertaking was done to show which methods hold the most promise for the near future. The methods investigated include LIGA, micromilling, jet molding, three dimensional printing, microcasting, micro-injection molding, metal injection molding, Microforming, and microextrusion. This study presents a technique overview, assembly issues, an applications survey, basic cost modeling and a survey of the relevant intellectual property.
by Abel Z. Hastings.
M.Eng.
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Britton, Joe. "Microfabrication techniques for trapped ion quantum information processing." Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3337078.
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Boyer, Nathan Edward. "Microfabrication with Smooth, Thin CNT/Polymer Composite Sheets." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/5923.
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Carbon nanotube (CNT)/polymer composite sheets can be extremely high strength and lightweight, which makes them attractive for fabrication of mechanical structures. This thesis demonstrates a method whereby smooth, thin CNT/polymer composite sheets can be fabricated and patterned on the microscale using a process of photolithography and plasma etching. CNT/polymer composites were made from CNTs grown using chemical vapor deposition using supported catalyst growth and floating catalyst growth. The composite sheets had a roughness of approximately 30nm and were about 61¼m or 261¼m depending on whether they were made from supported catalyst grown or floating catalyst grown CNTs. The composites were patterned using an oxygen plasma as the etchant and a hard mask of silicon nitride.
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Ghio, Simone. "Design and microfabrication of multifunctional bio-inspired surfaces." Doctoral thesis, Università degli studi di Trento, 2018. https://hdl.handle.net/11572/367604.
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In this thesis, we used CMOS-like technologies to produce improved, hierarchical multifunctional bioinspired surfaces. Different natural surfaces have been surveyed including well-known lotus leaf, sharkskin, back of the Namib Desert beetle, butterfly wings, and legs of water-walking insects. The lotus leaf features superhydrophobicity, which leads to low adhesion and self-cleaning. Sharkskin is composed of ripples that manage to reduce skin-friction and thus drag resistance. The Namib Desert beetle, harvests water from the heterogeneous pattern having hydrophilic/hydrophobic bumps on his back. Butterfly wings have re-entrant structures that manage to reach superhydrophobicity from a hydrophilic substrate. Hairy legs of water-walking insects are superhydrophobic with low adhesion that allows them to fight and jump on water.
In chapter 1, we have undertaken a review of bioinspired surfaces that emulate the abilities of such natural surfaces.
Then, in chapter 2 we have described the innovative CMOS-like techniques used for generating several hierarchical and re-entrant microstructures.
Chapter 3 depicts the analysis of surfaces with hierarchical structures generated with a fast and easy process; this latter forms a second hierarchical level composed of random pyramidal elements using wet etching. Surfaces realized with this process manage to reach remarkably high contact angle and low contact angle hysteresis. Additionally, in this chapter we have introduced an analytical model to study the stability of Cassie-Baxter state over Wenzel state for these hierarchical surfaces.
In chapter 4 the fabrication and analysis of surfaces composed of controlled hierarchical levels, which combine sharkskin with single-level lotus leaf-inspired pillared structures are reported. These particular hierarchical surfaces are demonstrated to hold high superhydrophobic properties along with low skin-friction. The superhydrophobicity of these surfaces has been characterized in a series of tests on an inclined plane. The data extrapolated from this measurement was used to evaluate the total dissipated energy of the sliding drop. Combining the data collected during this experiment with contact angle and contact angle hysteresis measurements we propose a global parameter that evaluates the superhydrophobic “level†of a surface.
Furthermore, in chapter 5 similar hierarchical surfaces have also been tested for water harvesting together with single-level pillared surfaces that feature heterogeneous chemistry with hydrophilic/hydrophobic spot on every single pillar.
In chapter 6 a series of tests have also been performed on butterfly-inspired surfaces. Although the substrate of such surfaces is hydrophilic, thanks to the re-entrant structures the surfaces reach high level of hydrophobicity. An implemented mathematical model and experimental test confirm the stability of this hydrophobic state.
In chapter 7, we describe two sets of surfaces inspired by the hairy legs of water walking insect the first is composed of stretchable pyramidal-pillars and the second of truncated-conical silicon pillars. The ability of sharp structures to easily detach from water surfaces is exploited to change the contact angle value of a water drop deposed on this fast type of stretchable micropatterned surface. A mathematical model has been implemented and experimental tests have been carried out to evaluate the stability of the water-air composite interface on both types of microstructured surfaces. In particular, in the polymeric surfaces elasto-capillarity seams to influence the metastability of the Cassie-Baxter state.
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Ghio, Simone. "Design and microfabrication of multifunctional bio-inspired surfaces." Doctoral thesis, University of Trento, 2018. http://eprints-phd.biblio.unitn.it/2854/1/Thesis_GHIO_S..pdf.
Full textAbstract:
In this thesis, we used CMOS-like technologies to produce improved, hierarchical multifunctional bioinspired surfaces. Different natural surfaces have been surveyed including well-known lotus leaf, sharkskin, back of the Namib Desert beetle, butterfly wings, and legs of water-walking insects. The lotus leaf features superhydrophobicity, which leads to low adhesion and self-cleaning. Sharkskin is composed of ripples that manage to reduce skin-friction and thus drag resistance. The Namib Desert beetle, harvests water from the heterogeneous pattern having hydrophilic/hydrophobic bumps on his back. Butterfly wings have re-entrant structures that manage to reach superhydrophobicity from a hydrophilic substrate. Hairy legs of water-walking insects are superhydrophobic with low adhesion that allows them to fight and jump on water.
In chapter 1, we have undertaken a review of bioinspired surfaces that emulate the abilities of such natural surfaces.
Then, in chapter 2 we have described the innovative CMOS-like techniques used for generating several hierarchical and re-entrant microstructures.
Chapter 3 depicts the analysis of surfaces with hierarchical structures generated with a fast and easy process; this latter forms a second hierarchical level composed of random pyramidal elements using wet etching. Surfaces realized with this process manage to reach remarkably high contact angle and low contact angle hysteresis. Additionally, in this chapter we have introduced an analytical model to study the stability of Cassie-Baxter state over Wenzel state for these hierarchical surfaces.
In chapter 4 the fabrication and analysis of surfaces composed of controlled hierarchical levels, which combine sharkskin with single-level lotus leaf-inspired pillared structures are reported. These particular hierarchical surfaces are demonstrated to hold high superhydrophobic properties along with low skin-friction. The superhydrophobicity of these surfaces has been characterized in a series of tests on an inclined plane. The data extrapolated from this measurement was used to evaluate the total dissipated energy of the sliding drop. Combining the data collected during this experiment with contact angle and contact angle hysteresis measurements we propose a global parameter that evaluates the superhydrophobic “level” of a surface.
Furthermore, in chapter 5 similar hierarchical surfaces have also been tested for water harvesting together with single-level pillared surfaces that feature heterogeneous chemistry with hydrophilic/hydrophobic spot on every single pillar.
In chapter 6 a series of tests have also been performed on butterfly-inspired surfaces. Although the substrate of such surfaces is hydrophilic, thanks to the re-entrant structures the surfaces reach high level of hydrophobicity. An implemented mathematical model and experimental test confirm the stability of this hydrophobic state.
In chapter 7, we describe two sets of surfaces inspired by the hairy legs of water walking insect the first is composed of stretchable pyramidal-pillars and the second of truncated-conical silicon pillars. The ability of sharp structures to easily detach from water surfaces is exploited to change the contact angle value of a water drop deposed on this fast type of stretchable micropatterned surface. A mathematical model has been implemented and experimental tests have been carried out to evaluate the stability of the water-air composite interface on both types of microstructured surfaces. In particular, in the polymeric surfaces elasto-capillarity seams to influence the metastability of the Cassie-Baxter state.
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Yang, Yanyin. "Synthesis, characterization, microfabrication and biological applications of conducting polymers." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1127316668.
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Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xv, 192 p.; also includes graphics (some col.). Includes bibliographical references (p. 183-192). Available online via OhioLINK's ETD Center
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Chien, Hsin-I. "Microfabrication of barium strontium titanate BaxSr(1-x)TiO3." Thesis, London South Bank University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.618692.
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Forsberg, Pontus. "Diamond Microfabrication for Applications in Optics and Chemical Sensing." Doctoral thesis, Uppsala universitet, Mikrosystemteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-192567.
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Diamond is a material with many exceptional properties. In this thesis methods for fabrication of microstructures as well as several applications of such structures in optics, microfluidics and electrochemistry are presented. A method for etching deep and highly precise gratings is described. This method was used to fabricate circularly symmetric half wave plates for use in vector vortex coronagraphs. Such coronagraphs are a very promising approach to the direct imaging of extrasolar planets. By varying the lateral etch rate of the aluminum mask during diamond etching in an inductively coupled plasma, the sidewall angle of the etched structures could be controlled. This method was used to make smooth sloped sides on a waveguide for coupling light into it. Antireflective structures that drastically reduced the surface reflection in a wavelength band between 10 and 50 µm were also fabricated. An array of boron doped diamond microelectrodes for electrochemical measurements in a microchannel was fabricated and tested, showing very good stability and reusability. Several hundred hours of use did not adversely affect their performance and no damage to them could be detected by atomic force microscopy or scanning electron microscopy. Superhydrophobic surfaces in diamond were demonstrated, using both hydrogen and fluorine termination. Hydrogen termination on a flat surface gives contact angles below 90°. To achieve a superhydrophobic surface with this low intrinsic hydrophobicity, structures looking like microscopic nail heads were fabricated. The effect of water pressure on immersed superhydrophobic surfaces was also studied and it was found that the collapse of the superhydrophobic state due to pressure was sometimes reversible as the pressure was lowered. Finally, a method was tested for functionalizing diamond surfaces using block copolymers of polyethylene oxide and polypropylene oxide to both passivate the surface and to attach synthetic binder molecules. This method was found to give very high signal to noise ratios when detecting C-reactive protein.
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Sterling, Robin C. "Ytterbium ion trapping and microfabrication of ion trap arrays." Thesis, University of Sussex, 2012. http://sro.sussex.ac.uk/id/eprint/39684/.
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Over the past 15 years ion traps have demonstrated all the building blocks required of a quantum computer. Despite this success, trapping ions remains a challenging task, with the requirement for extensive laser systems and vacuum systems to perform operations on only a handful of qubits. To scale these proof of principle experiments into something that can outperform a classical computer requires an advancement in the trap technologies that will allow multiple trapping zones, junctions and utilize scalable fabrication technologies. I will discuss the construction of an ion trapping experiment, focussing on my work towards the laser stabilization and ion trap design but also covering the experimental setup as a whole. The vacuum system that I designed allows the mounting and testing of a variety of ion trap chips, with versatile optical access and a fast turn around time. I will also present the design and fabrication of a microfabricated Y junction and a 2- dimensional ion trap lattice. I achieve a suppression of barrier height and small variation of secular frequency through the Y junction, aiding to the junctions applicability to adiabatic shuttling operations. I also report the design and fabrication of a 2-D ion trap lattice. Such structures have been proposed as a means to implement quantum simulators and to my knowledge is the first microfabricated lattice trap. Electrical testing of the trap structures was undertaken to investigate the breakdown voltage of microfabricated structures with both static and radio frequency voltages. The results from these tests negate the concern over reduced rf voltage breakdown and in fact demonstrates breakdown voltages significantly above that typically required for ion trapping. This may allow ion traps to be designed to operate with higher voltages and greater ion-electrode separations, reducing anomalous heating. Lastly I present my work towards the implementation of magnetic fields gradients and microwaves on chip. This may allow coupling of the ions internal state to its motion using microwaves, thus reducing the requirements for the use of laser systems.
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Losey, Matthew W. "Novel multiphase chemical reaction systems enabled by microfabrication technology." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8634.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2001.Includes bibliographical references (p. 237-251).
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, staggered arrays of microstructural features to promote mixing, and the integration of sensing and temperature control. Other uses of microfabrication include the incorporation of porous silicon as a high surface area catalyst support. In all, performing multiphase chemistry on a chip has been demonstrated to have inherent advantages, particularly for those fast reactions that can benefit from improved mixing and mass transfer.
by Matthew W. Losey.
Ph.D.
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Ge, Yufei S. M. Massachusetts Institute of Technology. "Microfabrication of surface electrode ion traps for quantum manipulation." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/99280.
Full textAbstract:
Thesis: S.M., Massachusetts Institute of Technology, Department of Physics, 2015.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 123-132).
Trapped ions are a promising approach to quantum computation. This approach uses a qubit state which is the atomic state and quantum motional state of a trapped ion to encode information, and uses laser-ion interactions to manipulate the qubit state. A major obstacle to the realization of a practical ion trap quantum computer is decoherence. In trapped ion quantum computation experiments, decoherence is dominated by the uncontrolled heating of ion motional states. In this thesis, we present the detailed microfabrication of several series of surface electrode linear Paul traps made from different electrode materials, followed by the ion motional heating experiment results for these traps. We demonstrate that the ion motional heating strongly depends on fabrication process. In particular, we explore how grain size and grain orientation affect the ion motional heating rate. This thesis is divided into two parts. In the first part, we describe the fabrication of gold, silver, aluminum and niobium traps from different processes, which results in various surface morphologies and grain structures. Ion motional heating rate measurements are then conducted both at cryogenic temperatures and at room temperature. We employ a physical model based on the fluctuating patch potential theory to explain the ion heating behavior. We use gold traps to study the temperature and frequency dependence of the ion heating. We use aluminum traps to study the ion heating dependence on the amorphous dielectric layer. And we use silver traps to study the ion heating dependence on the grain structure. These results suggest that excess ion heating could possibly be suppressed by suitable fabrication selection. In the second part, we present the process of using SU8 to fabricate a multilayer surface electrode point Paul trap, which has the advantage of allowing ion height variation within the same trap and enables testing of the distance dependence of ion heating.
by Yufei Ge.
S.M.
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Wasley, Thomas J. "Digitally driven microfabrication of 3D multilayer embedded electronic systems." Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/23237.
Full textAbstract:
The integration of multiple digitally driven processes is seen as the solution to many of the current limitations arising from standalone Additive Manufacturing (AM) techniques. A technique has been developed to digitally fabricate fully functioning electronics using a unique combination of AM technologies. This has been achieved by interleaving bottom-up Stereolithography (SL) with Direct Writing (DW) of conductor materials alongside mid-process development (optimising the substrate surface quality), dispensing of interconnects, component placement and thermal curing stages. The resulting process enables the low-temperature production of bespoke three-dimensional, fully packaged and assembled multi-layer embedded electronic circuitry. Two different Digital Light Processing (DLP) Stereolithography systems were developed applying different projection orientations to fabricate electronic substrates by selective photopolymerisation. The bottom up projection orientation produced higher quality more planar surfaces and demonstrated both a theoretical and practical feature resolution of 110 μm. A top down projection method was also developed however a uniform exposure of UV light and planar substrate surface of high quality could not be achieved. The most advantageous combination of three post processing techniques to optimise the substrate surface quality for subsequent conductor deposition was determined and defined as a mid-processing procedure. These techniques included ultrasonic agitation in solvent, thermal baking and additional ultraviolet exposure. SEM and surface analysis showed that a sequence including ultrasonic agitation in D-Limonene with additional UV exposure was optimal. DW of a silver conductive epoxy was used to print conductors on the photopolymer surface using a Musashi dispensing system that applies a pneumatic pressure to a loaded syringe mounted on a 3-axis print head and is controlled through CAD generated machine code. The dispensing behaviour of two isotropic conductive adhesives was characterised through three different nozzle sizes for the production of conductor traces as small as 170 μm wide and 40 μm high. Additionally, the high resolution dispensing of a viscous isotropic conductive adhesive (ICA) also led to a novel deposition approach for producing three dimensional, z-axis connections in the form of high freestanding pillars with an aspect ratio of 3.68 (height of 2mm and diameter of 550μm). Three conductive adhesive curing regimes were applied to printed samples to determine the effect of curing temperature and time on the resulting material resistivity. A temperature of 80 °C for 3 hours resulted in the lowest resistivity while displaying no substrate degradation. ii Compatibility with surface mount technology enabled components including resistors, capacitors and chip packages to be placed directly onto the silver adhesive contact pads before low-temperature thermal curing and embedding within additional layers of photopolymer. Packaging of components as small as 0603 surface mount devices (SMDs) was demonstrated via this process. After embedding of the circuitry in a thick layer of photopolymer using the bottom up Stereolithography apparatus, analysis of the adhesive strength at the boundary between the base substrate and embedding layer was conducted showing that loads up to 1500 N could be applied perpendicular to the embedding plane. A high degree of planarization was also found during evaluation of the embedding stage that resulted in an excellent surface finish on which to deposit subsequent layers. This complete procedure could be repeated numerous times to fabricate multilayer electronic devices. This hybrid process was also adapted to conduct flip-chip packaging of bare die with 195 μm wide bond pads. The SL/DW process combination was used to create conductive trenches in the substrate surface that were filled with isotropic conductive adhesive (ICA) to create conductive pathways. Additional experimentation with the dispensing parameters led to consistent 150 μm ICA bumps at a 457 μm pitch. A flip-chip bonding force of 0.08 N resulted in a contact resistance of 2.3 Ω at a standoff height of ~80 μm. Flip-chips with greater standoff heights of 160 μm were also successfully underfilled with liquid photopolymer using the SL embedding technique, while the same process on chips with 80 μm standoff height was unsuccessful. Finally the approaches were combined to fabricate single, double and triple layer circuit demonstrators; pyramid shaped electronic packages with internal multilayer electronics; fully packaged and underfilled flip-chip bare die and; a microfluidic device facilitating UV catalysis. This new paradigm in manufacturing supports rapid iterative product development and mass customisation of electronics for a specific application and, allows the generation of more dimensionally complex products with increased functionality.
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Le, Van Suu Thierry. "Etude analytique, conception et microfabrication de microphones capacitifs miniatures." Le Mans, 2008. http://cyberdoc.univ-lemans.fr/theses/2008/2008LEMA1016.pdf.
Full textAbstract:
Au cours de la dernière décennie, les capteurs capacitifs de pression acoustique fabriqués sur puce silicium, ont fait l'objet d'études théoriques, expérimentales et technologiques, de manière à réaliser des microphones miniatures qui présentent de l'intérêt dans de nombreuses applications. Ces études ont été menées plus particulièrement sur les systèmes d'architectures conventionnelles, c'est à dire sur la modélisation et la microfabrication de dispositifs qui comportent un diaphragme (considéré comme une membrane), une électrode arrière plane (perforée ou non), et une couche de fluide visqueux et thermoconducteur située dans cet entrefer, prolongé par un réservoir périphérique. Le travail présenté dans ce mémoire de thèse constitue dans l'ensemble une extension de ceux menés depuis plusieurs années dans plusieurs laboratoires de par le monde dont le Laboratoire d'Acoustique de l'Université du Maine. Une nouvelle architecture dans laquelle l'électrode arrière n'est plus plane a été proposée récemment dans la littérature. Les méthodes analytiques classiques utilisées ont conduit à des expressions simples pour la sensibilité du microphone, mais elles se trouvent limitées lorsque l'étude requiert des résultats très précis. C'est ainsi qu'une solution générale est proposée ici, qui prend en compte le couplage fluidemembrane d'une manière plus réaliste. Par ailleurs, le diaphragme est habituellement considéré comme circulaire et/ou comme ayant un comportement de membrane. C'est ainsi que, dans la seconde partie de cette étude analytique, des solutions sont proposées pour des plaques carrées, chargées par le fluide, incluant une extension au cas du ruban précontraint qui doivent répondent aux attentes de la communauté. La seconde partie de la thèse est double: -i) un microphone miniature, réalisé à l'aide des procédés de micro fabrication disponibles dans la centrale de micro technologies localisée à l'ENSIM, a été conçu et les principales étapes de sa réalisation ont été validées, ii) Une méthode expérimentale de mesure simultanée du module d'Young et des contraintes résiduelles est présentée et validée, qui se substitue avantageusement à notre sens aux méthodes en usage qui ne permettent l'accès qu'à un seul des deux paramètres, l'autre étant supposé connuDuring the last decade, capacitive acoustic pressure sensors fabricated on silicon chips was the subject of theoretical, experimental and technological studies, in order to design miniaturized microphones whose interest in many applications would be of importance. These studies concentrate on the devices classically designed, namely on the modelling and on the micro machining of devices comprising a diaphragm (considered as a membrane), a planar perforated (or not) backing electrode, and a viscous and thermalconducting fiuid trapped between both and/or enclosed by a peripheral reservoir. Ln many respects, the work presented in this PhD thesis is an extension of those carried out for several years in laboratories around the world, including the Laboratoire d'Acoustique de l'Université du Maine. A new design in which the backing electrode is non-planar has been proposed recently in the literature. A standard analytic procedure yielded simple expression for the sensitivity of the microphone, whose the limitations can be pointed out when a precise solution is needed. Therefore herein, a general solution is proposed, which accounts for the coupling between the membrane and the fiuid layer in a more realistic way. On the other hand, the diaphragm is usually assumed to be circular and/or to behave as a membrane. The aim of the second chapter of the analytical studies presented here is to propose solutions for square loaded plates, including extensions for stretched ribbon, leading to awaited results. The second part of the thesis is twofold : -i) a miniaturised microphone, made using the micro machining pro cesses available in the clean room facility at ENSIM, has been designed and the main process steps have been validated, -ii) an experimental method for measuring simultaneously the Young's modulus and the residual stress is suggested and validated, supplanting in our opinion other known methods which usually provide only one of these two parameters (assuming that the other one is known)
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Hou, Linlin. "Advanced 3D Microfabrication and Demonstration of Arrayed Electrowetting Microprisms." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1328546291.
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Peeni, Bridget A. "Microfabrication and evaluation of planar thin-film microfluidic devices /." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1564.pdf.
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Le, Van Suu Thierry Bruneau Michel Durand Stéphane. "Etude analytique, conception et microfabrication de microphones capacitifs miniatures." [S.l.] : [s.n.], 2008. http://cyberdoc.univ-lemans.fr/theses/2008/2008LEMA1016.pdf.
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Peeni, Bridget Ann. "Microfabrication and Evaluation of Planar Thin-Film Microfluidic Devices." BYU ScholarsArchive, 2006. https://scholarsarchive.byu.edu/etd/797.
Full textAbstract:
Over the past 15 years, research in the field of microfluidics has rapidly gained popularity. By seeking to miniaturize and automate separation-based analysis, microfluidic research seeks to improve current methods through decreased cost, analysis time, and sources of contamination. My work has focused on developing a novel fabrication method, based on standard microfabrication techniques, to create thin-film microfluidic devices. This microfabrication format makes it possible to generate devices that provide high efficiencies, enable mass fabrication, and provide a platform capable of integrating the microfluidic and electronic components necessary for a micro-total analysis system (μ-TAS). Device fabrication combines the processes of photolithography, thermal evaporation, plasma enhanced chemical vapor deposition (PECVD), and wet chemical etching to ultimately provide hollow-core channels. When these microcapillaries are filled with buffer and potentials are applied across them, control of the flow in the channels can be established. By designing intersecting microchannels having an offset “T†geometry, I have been able to inject and electrophoretically separate three fluorescently labeled amino acids and obtain efficiencies of over 2500 theoretical plates. Through the addition of commercially available electroosmotic flow reducing coatings, I have been able to improve the separation of these amino acids, decreasing the run time by approximately 6 fold and increasing the efficiency by as much as 10 fold. Through the use of these coatings I have also been able to carry out electrophoretic separations of three peptides. My most recent work has focused on the polymerization of acrylamide gels in these channels. A method for the selective placement of a gel has been developed using a prepolymer solution with a light-sensitive initiator. Further work to adjust the polymer pore size and interface with ampholyte-containing gels should allow methods such as capillary gel electrophoresis (CGE), preconcentration, and two dimensional (isolectric focusing and CGE) separations to be performed. The development of gel-based analysis methods, along with other fluidic and electrical capacities, should move thin-film microdevices toward the realization of the lab-on-a-chip concept.
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Clark, Sarah L. (Sarah Louise) 1972. "Engineering the microfabrication of layer-by-layer polyelectrolyte assembly." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9509.
Full textAbstract:
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1999.Includes bibliographical references.
The feasibility of microstructuring polyelectrolyte multilayers has been established by using the layer-by-layer assembly technique in combination with patterned self-assembled monolayers (SAMs). SAMs of a carboxylic acid surface (COOH) and a triethylene glycol surface (EG) were used to promote and resist polyelectrolyte adsorption. respectively. Processing conditions necessary for the selective deposition of both weak and strong polyelectrolytes were established as a function of polyelectrolyte molecular weight. ionic content, ion type. and pH. Low molecular weight polyelectrolytes adsorbed more selectively on patterned SAM surfaces than high molecular weight polyelectrolytes. Strong polyelectrolytes multilayers of sulfonated poly(styrene) (SPS) and polydiallyldimethyl ammonium chloride (PDAC) required the addition of 0.1 M NaCl to the polyelectrolyte dipping solutions to optimize selective deposition. Adding 1.0 M NaCl to each polyelectrolyte solution and including a periodic drying step in the multilayer fabrication process reversed the templating ability of the COOH and EG SAMs for the SPS/PDAC multilayers. Weak polyelectrolytes such as linear (polyethylenimine) (LPEI), branched (polyethylenimine) (BPEI), poly(allylamine hydrochloride (PAH), poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA) were adsorbed at pH 2.5. 4.8, 7, and IO on patterned COOH and EG SAMs to determine optimal patterned deposition conditions. Each polyacid and polyamine had a secondary interaction that changed the affinity of the multi layers for the COOH and EG surfaces. The technique was also extended to include an optically active dye in the multilayers. Imaging the patterned dye multilaycrs under a fluorescence microscope produced light emission from the selectively adsorbed dye molecules. The different conditions and interactions that produced selective deposition of polyelectrolyte multilayers were combined to build complex multilayer structures. A cladding structure was produced by depositing a blanketing layer of strong polyelectrolytes on preformed patterned multilayers. A different complex structure of polyelectrolytes was fabricated by selectively adsorbing a second polyelectrolyte system within the patterned structure of strong polyelectrolyte multilayers. This assembly was accomplished by utilizing secondary interactions of weak polyelectrolyte multilayers with the EG surface.
by Sarah L. Clark.
Ph.D.
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Faria, Bellani Caroline. "Electrospun biocomposites and 3D microfabrication for bone tissue enginneering." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAE028/document.
Full textAbstract:
Des membranes biodégradables en polycaprolactone pour la régénération osseuse guidée, obtenues par electrospinning, incorporés avec différents rapports de nanocomposites de nanocristaux de cellulose et du Biosilicate®, ont été fabriquées, avec propriétés mécaniques et ostéogéniques améliorés. En tant que stratégie de vascularisation rapide, un greffon biomimétique suturable obtenue par fusion de membranes électrofilées a été fabriqué, avec des motifs poreux obtenus par micro- usinage au laser pour permettre la migration des cellules endothéliales vers le greffon osseux. Les motifs poreux créés sur les greffes suturables ont permis aux cellules endothéliales migrer vers la culture 3D des ostéoblastes dans des hydrogels en gélatine méthacryloyl (GelMA), et des structures 3D ont été observées. Par conséquent, cette stratégie peut être utilisée pour améliorer la taille et la survie des implants osseux biofabriqués, en accélérant la traduction clinique de l'ingénierie du tissu osseuxBiodegradable membranes for guided bone regeneration, made of polycaprolactone, obtained by electrospinning, incorporated with different nanocomposite ratios of cellulose nanocrystals and Biosilicate®, have been manufactured, with improved mechanical and osteogenic properties. As fast vascularization strategy, a suturable biomimetic graft obtained by fusion of electrospun membranes was fabricated, with porous patterns obtained by laser micromachining to allow migration of endothelial cells to the bone graft. The porous patterns created on the suturable grafts allowed the endothelial cells to migrate to the 3D culture of the osteoblasts in gelatin methacryloyl (GelMA), and 3D structures were observed. Therefore, this strategy can be used to improve the size and survival of biofabricated bone implants, accelerating the clinical translation of bone tissue engineering
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Carletti, Eleonora. "3D scaffolds for tissue engineering produced by microfabrication technology." Doctoral thesis, Università degli studi di Trento, 2009. https://hdl.handle.net/11572/368658.
Full textAbstract:
Rapid prototyping techniques (RP) hold great promise for designing 3-dimensional (3-D) regular and ordered scaffolds for tissue engineering applications. With these techniques, good architecture reproducibility as well as porosity control of the structure can be obtained.
This work dealt with the fabrication of tissue engineering scaffolds with regular micrometric geometry by using an in-house built microfabrication system.
Poly(D,L-lactic acid) (PDLA), poly(D,L-lactic-co-glycolic acid) (PLGA) and chitosan scaffolds presenting homogeneously distributed 100 µm size pores were fabricated. Fabrication consisted in a layer by layer deposition of filaments of PDLA and PLGA dichloro methane/dimethylformamide (DMC/DMF) solutions and chitosan acetic acid solutions, respectively, on a plate moving with micrometric precision in the x,y,z directions.
Additional chitosan scaffolds filled with amorphous calcium phosphate (ACP) particles were also microfabricated, considering the possibility to take advantage of the osteoconductive character of ACP for bone tissue regeneration applications.
The in-house built system utilizes highly accurate 3-D micro-positioning slides having a resolution up to 1 µm. Through a microsyringe equipped with a micro-needle having 60 µm inner diameter, an automatic pumping system extrudes a filament of the selected solution on a plate. The plate is connected to three slides moving independently in the x,y,z directions. A computer controls the slides movement so that the filament that deposits on the plate builds layer by layer scaffolds of designed geometry.
Rheological tests were used to characterize the polymer solution viscosities while thermal analysis (DSC), ATR-FTIR and dynamic mechanical tests (DMTA) have characterized the produced scaffold. Cast films from the same polymer solutions were used as control. Preliminary biological evaluations were done by seeding on the scaffolds osteoblasts (MG63) and fibroblasts (MRC5) cell lines.
SEM and LV-SEM imaging evidenced scaffold morphology and cell adhesion and growth behavior.
Surface topography of ACP filled chitosan scaffolds has been determined by atomic force microscopy (AFM) and their surface elemental composition evaluated by energy dispersive spectroscopy (EDS).
In addition to the above activity a second part of the work revolves around fused deposition modeling (FDM) scaffolds cell cultured with human osteoblasts over different time.
Human osteoblasts, isolated from the tibial sponge bone, were seeded on medical-grade polycaprolactone-tricalcium phosphate (mPCL-TCP 80:20) and poly(D, L lactic acid) - tricalcium phosphate (PDLLA-TCP 90:10) scaffolds.
Furthermore, once the cells had reached the confluent stage, osteogenic media was used during cell culture to induce matrix formation. The newly formed matrix could provide a physical support forming an osteoblast sheet layer that was used to wrap the scaffold.
Cells attachment, growing and proliferation were measured by imaging analysis techniques.
Cells viability was evaluated by confocal laser microscopy after fluorescein diacetate (FDA)/ propidium iodide (PI) staining.
The extent of cell proliferation was examined by PicoGreenTM quantification assay through the calculated cell DNA amount profile.
In general, the work aimed at investigating how the two techniques, able to produce tissue engineering scaffolds with ordered structure, could assist the cellular growth and tissue regeneration.
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Carletti, Eleonora. "3D scaffolds for tissue engineering produced by microfabrication technology." Doctoral thesis, University of Trento, 2009. http://eprints-phd.biblio.unitn.it/90/1/thesisCarletti.pdf.
Full textAbstract:
Rapid prototyping techniques (RP) hold great promise for designing 3-dimensional (3-D) regular and ordered scaffolds for tissue engineering applications. With these techniques, good architecture reproducibility as well as porosity control of the structure can be obtained.
This work dealt with the fabrication of tissue engineering scaffolds with regular micrometric geometry by using an in-house built microfabrication system.
Poly(D,L-lactic acid) (PDLA), poly(D,L-lactic-co-glycolic acid) (PLGA) and chitosan scaffolds presenting homogeneously distributed 100 µm size pores were fabricated. Fabrication consisted in a layer by layer deposition of filaments of PDLA and PLGA dichloro methane/dimethylformamide (DMC/DMF) solutions and chitosan acetic acid solutions, respectively, on a plate moving with micrometric precision in the x,y,z directions.
Additional chitosan scaffolds filled with amorphous calcium phosphate (ACP) particles were also microfabricated, considering the possibility to take advantage of the osteoconductive character of ACP for bone tissue regeneration applications.
The in-house built system utilizes highly accurate 3-D micro-positioning slides having a resolution up to 1 µm. Through a microsyringe equipped with a micro-needle having 60 µm inner diameter, an automatic pumping system extrudes a filament of the selected solution on a plate. The plate is connected to three slides moving independently in the x,y,z directions. A computer controls the slides movement so that the filament that deposits on the plate builds layer by layer scaffolds of designed geometry.
Rheological tests were used to characterize the polymer solution viscosities while thermal analysis (DSC), ATR-FTIR and dynamic mechanical tests (DMTA) have characterized the produced scaffold. Cast films from the same polymer solutions were used as control. Preliminary biological evaluations were done by seeding on the scaffolds osteoblasts (MG63) and fibroblasts (MRC5) cell lines.
SEM and LV-SEM imaging evidenced scaffold morphology and cell adhesion and growth behavior.
Surface topography of ACP filled chitosan scaffolds has been determined by atomic force microscopy (AFM) and their surface elemental composition evaluated by energy dispersive spectroscopy (EDS).
In addition to the above activity a second part of the work revolves around fused deposition modeling (FDM) scaffolds cell cultured with human osteoblasts over different time.
Human osteoblasts, isolated from the tibial sponge bone, were seeded on medical-grade polycaprolactone-tricalcium phosphate (mPCL-TCP 80:20) and poly(D, L lactic acid) - tricalcium phosphate (PDLLA-TCP 90:10) scaffolds.
Furthermore, once the cells had reached the confluent stage, osteogenic media was used during cell culture to induce matrix formation. The newly formed matrix could provide a physical support forming an osteoblast sheet layer that was used to wrap the scaffold.
Cells attachment, growing and proliferation were measured by imaging analysis techniques.
Cells viability was evaluated by confocal laser microscopy after fluorescein diacetate (FDA)/ propidium iodide (PI) staining.
The extent of cell proliferation was examined by PicoGreenTM quantification assay through the calculated cell DNA amount profile.
In general, the work aimed at investigating how the two techniques, able to produce tissue engineering scaffolds with ordered structure, could assist the cellular growth and tissue regeneration.
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Paik, Sokwon. "Spatially resolved temperature and heat flux measurements for slow evaporating droplets heated by a microfabricated heater array." Diss., Texas A&M University, 2006. http://hdl.handle.net/1969.1/3819.
Full textAbstract:
The evaporation phenomenon of a liquid droplet was investigated by using microfabricated heaters. All 32 microheaters were designed to have the same resistance. Gold microheaters worked both as temperature indicators and as heaters. The first experiment was performed under a constant voltage mode to investigate the temperature and heat flux variation of the heated surface by the evaporating droplet. The second experiment was performed under constant temperature mode to investigate the spatial and temporal heat flux variation of the constant temperature heater surface by the evaporating droplet heater. Droplet evaporation was recorded with a CCD camera. Experimental data showed temperature and heat flux variations inside and outside of the droplet with respect to time and radial position from the center of the droplet by tomographic deconvolution.
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BANERJEE, SHOMIR. "A PROTOTYPE ON-CHIP MICRO-HEATER FOR DISPOSABLE MICRO-PCR MODULE." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1038001719.
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Zhao, Xuan. "Conception and fabrication of reusable microfluidic tools to study the dynamics of biological phenomena : application to antibiotic influx/efflux in bacteria and to cell migration during mouse development." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS226/document.
Full textAbstract:
Nous voulons mettre en évidence et analyser les réponses de systèmes biologiques à l’introduction de perturbations et de modulations spatio-temporelles. Plus précisément, afin de développer des stratégies innovantes pour l’étude des systèmes biologiques, nous proposons d’utiliser des outils microfluidiques. Nous concevons des microsystèmes adaptés qui peuvent influer localement sur les comportements biologiques, ceci afin qu’un experimentateur macroscopique puisse contrôler l’environnement externe des objects biologiques dont l’échelle est microscopique. Cette stratégie d’ingénierie est générique et multidisciplinaire. Au cours de cette thèse, elle a été mise en œuvre dans le cadre de deux projets collaboratifs, d’une part à l’échelle de la bactérie E.coli, et d’autre part à celle de l’embryon de souris à un stade post-implantation précoce. Les objets d’étude choisis sont caractéristiques à bien des égards des champs biologiques concernés : taille, représentativité, complexité.Nous avons mis nos compétences de spécialistes en conception et en fabrication de dispositifs fluidiques au service de la ligne DISCO du synchrotron SOLEIL et de l’équipe d’embryologie de la souris de l’IRIBHM. Le nœud de mon travail a été de concevoir et fabriquer les outils microfluidiques réutilisables pour des recherches génériques, qui permettent aux biologistes de se dispenser de l’utilisation d’une salle blanche.Plus précisément, le projet de microbiologie à SOLEIL avait pour object l’étude de l’influx et l’efflux de molécules antibiotiques dans des bactéries. Pour ce faire, nous avons developpé un dispositif réutilisable pour immobiliser les microorganisms et changer leur environnement chimique pendant l’imagerie en microscopie d’epifluorescence dans l’UV. Cette étude s’effectue en utilisant deux partenaires typiques : la bactérie Escherichia coli et un médicament de la famille des fluoroquinolones. Le projet d’embryologie a reposé sur l’électroporation localisée d’acides nucléiques au sein d’embryons de souris et le suivi des migrations cellulaires. Au cours de cette thèse, nous avons développé non seulement des microdispositifs réutilisables mais aussi des protocoles expérimentaux adaptés à l’utilisation de ces instruments miniaturisés.Plus précisément, le projet de microbiologie à SOLEIL avait pour object l’étude de l’influx et lantibiotiques dans des bactéries. Pour ce faire, nous avons developpé un dispositif réutilisable pour immobiliser lesmicroorganismes et changer leur environnement chimique pendant l’imagerie en microscopie d’épifluorescence dans l’UV.Cette étude s’effectue en utilisant deux partenaires typiques : la bactérie E. coli et un médicament de la famille desfluoroquinolones. Le projet d’embryologie a reposé sur l’électroporation localisée d’acides nucléiques des embryons desouris et le suivi des migrations cellulairesWe want to analyze the responses of biological systems to the introduction of perturbations and spatio-temporal modulations. More specifically, in order to develop innovative strategies for the study of biological systems, we propose to use microfluidic tools. We design adapted microsystems that can locally influence biological behaviors, so that a macroscopic experimenter can control the external environment of biological objects whose scale is microscopic. This engineering strategy is generic and multidisciplinary. In this thesis, it has been implemented in two collaborative projects, on one hand, on the scale of the E.coli bacterium and on the other hand on that of the embryo of mouse at an early stage post-implantation. The selected study objects are characteristic in many respects of the biological fields concerned: size, representativeness, complexity.We extended our expertise in fluidic device design and manufacturing to the service of the DISCO beamline of the synchrotron SOLEIL and the IRIBHM mouse embryology team. The key point of my work has been to design and manufacture reusable microfluidic tools for generic research, which allow biologists to dispense with the use of a clean room.More precisely, the project of microbiology at SOLEIL had for object the study of the influx and the efflux of antibiotic molecules in bacteria. To do this, we have developed a reusable device for immobilizing microorganisms and changing their chemical environment during UV imaging on epifluorescence microscopy. This study is carried out using two typical partners: the Escherichia coli bacterium and a drug from the fluoroquinolone family. The embryology project relied on the localized electroporation of nucleic acids within mouse embryos and the monitoring of cellular migrations.In this thesis, we have developed not only reusable micro-devices but also experimental protocols adapted to the use of these miniaturized instruments.More precisely, the microbiology project at SOLEIL focused on the influx and the efflux of antibiWe have developed a reusable device for immobilizing those microorganisms and changing their chemical environmentduring UV imaging on an epifluorescence microscopy. This study was carried out using two typical partners: thebacterium and a drug from the fluoroquinolone family. The embryology project relied on the localized electroporation ofnucleic acids into mouse embryos and the monitoring of cell migrations
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Cezar, Mehmet. "Development And Microfabrication Of Capacitive Micromachinedultrasound Transducers With Diamond Membranes." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12612958/index.pdf.
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This thesis presents the development and microfabrication of capacitive micromachined ultrasonic transducers (CMUT) with diamond membranes for the first time in the literature.
Although silicon and silicon nitride (Si3N4) membranes have been generally used as the membrane material in CMUTs. These membrane materials have moderate properties that can cause damage during the operation of CMUTs. In this thesis, a new material for the membrane is introduced for CMUTs. Diamond has exceptional potential in the area of micro-nano technologies due to unrivalled stiffness and hardness, excellent tribological performance, highly tailorable and stable surface chemistry, high thermal conductivity and low thermal expansion, high acoustic velocity of propagating waves, and biocompatibility. Based on these excellent material properties, diamond is employed in the new generation CMUT structures for more robust and reliable operations.
The microfabrication process of CMUT has been generally performed with either sacrificial release process or wafer bonding technique. High yield and low cost features of wafer bonding process makes it preferable for CMUT devices. In this thesis, plasma-activated direct wafer bonding process was developed for the microfabrication of 16-element 1-D CMUT arrays with diamond membranes. They were designed to operate at different resonance frequencies in the range of 1 MHz and 10 MHz with different cell diameters (120, 88, 72, 54, 44 &mum) and element spacing (250, 375 &mu
m). 1-D CMUT array devices can be used for focusing ultrasound applications. The electronic circuit for 1-D CMUT devices with diamond membranes was designed and implemented on PCB for the ultrasound focusing experiment. This electronic circuit generates continuous or burst AC signals of ±
15 V with different and adjustable phase shifting options at 3 MHz frequency. 16 elements of 72 &mu
m 1-D CMUT array were successfully tested. Fully functional 7 elements of 1-D CMUT array are focused at an axial distance of 5.81 mm on the normal to the CMUT center plane. The CMUT array was excited using 10 Vp&minus
p with 10 cycles sinusoidal signals at 3 MHz. The microfabrication process and focusing ultrasound of 1-D CMUT devices with diamond membranes are done successfully in this thesis.
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Rao, Radhakrishna A. "Nanoscale microfabrication prospects using proximity focused liquid metal ion sources /." Full text open access at:, 1988. http://content.ohsu.edu/u?/etd,183.
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Garud, Niharika Triplett Gregory Edward. "Shallow trench isolation process in microfabrication for flash (NAND) memory." Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/5622.
Full textAbstract:
Thesis (M.S.)--University of Missouri-Columbia, 2008.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 2, 2008) Includes bibliographical references.
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Luo, Mengdi. "Materials and microfabrication approaches for completely biodegradable wireless micromachined sensors." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53093.
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Implantable sensors have been extensively investigated to facilitate diagnosis or to provide a means to generated closed loop control of therapy by yielding in vivo measurements of physical and chemical signals. Biodegradable sensors which degrade gradually after they are no longer functionally needed exhibit great potential in acute or shorter-term medical diagnostic and sensing applications due to the advantages of (a) exclusion of the need to a secondary surgery for sensor removal, and (b) reduction of the risk of long-term infection.
The objective of this research is to design and characterize microfabricated RF wireless pressure sensors that are made of completely biodegradable materials and degrade at time-controlled manner (in the order of years and months). This was achieved by means of investigation of appropriate biodegradable materials and development of appropriate fabrication processes for these non-standard (Microelectromechanical systems) MEMS materials. Four subareas of research are performed:
(1) Design of sensors that operate wirelessly and are made of biodegradable materials. The structure of the wireless sensor consists a very compact and relatively simple design of passive LC resonant circuits embedded in a polymer dielectric package. To design the sensor with a particular resonant frequency range, an electromagnetic model of the sensor and a mechanical model for circular plate are developed. The geometry of the sensor is established based on the analytical and finite element simulations results. (2) Investigation of the biodegradable materials in the application of implantable biodegradable wireless sensors to achieve controllable degradation lifetimes. Commercially available and FDA approved biodegradable polymers poly(L-lactic acid) (PLLA) and a "shell-core" structure of poly(lactic-co-glycolic acid) (PLGA) and polyvinyl alcohol (PVA) are utilized as the dielectric package for slow and rapid degradation sensors, respectively. Biodegradable metallic zinc and zinc/iron couples are chosen as conductor materials. The degradation behavior of Zn and Zn/Fe-couple are investigated in vitro. (3) Development of novel fabrication processes. The process exploit the advantages of MEMS technology in fabricating miniaturized devices, while protecting vulnerable biodegradable materials from the strong and/or hazardous chemicals that are commonly used in conventional MEMS fabrication process. These new processes enable the fabrication of biocompatible and biodegradable 3-D devices with embedded, near-hermetic cavities. (4) Testing the pressure response functionality and studying the degradation behavior of the wireless biodegradable pressure sensors. Both PLLA-based and PLGA/PVA-based sensors are characterized in vitro by being immersed in 0.9% saline for prolonged time. All the sensors exhibit three stages of behavior in vitro: equilibration, functional lifetime, and performance degradation. During the functional lifetime, most sensors exhibit fully stable functionality. The PLLA-based sensors show no significant weight loss within 8 month and are expected to fully degrade after 2 years, while the PLGA/PVA-based sensors can degrade completely within 26 days.
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Bhatia, Sangeeta N. "Controlling cell-cell interactions in hepatic tissue engineering using microfabrication." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/10091.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Whitaker College of Health Sciences and Technology, 1997.Includes bibliographical references (leaves 147-169).
by Sangeeta N. Bhatia.
Ph.D.
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Aiyar, Avishek R. "Microfabrication of a MEMS piezoresistive flow sensor - materials and processes." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24696.
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Wong, Chun Keung. "Realization of integrated photonic devices using silicon-based materials and microfabrication technology /." access full-text access abstract and table of contents, 2009. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?phd-ee-b23750431f.pdf.
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Thesis (Ph.D.)--City University of Hong Kong, 2009."Submitted to Department of Electronic Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy." Includes bibliographical references.
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McAllister, Devin Vincent. "Microfabricated needles for transdermal drug delivery." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/11031.
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Cross, David Henry. "Laser induced chemical vapour deposition of aluminium." Thesis, Heriot-Watt University, 1992. http://hdl.handle.net/10399/815.
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Hu, Xinqun. "Design of a microchannel reactor for gas phase heterogeneous reactions : enhanced mass and heat transfer for process intensification." Thesis, University of Sheffield, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246984.
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Cartin, Charles. "DESIGN, FABRICATION, AND TESTING OF A PDMS MICROPUMP WITH MOVING MEMBRANES." VCU Scholars Compass, 2012. http://scholarscompass.vcu.edu/etd/2742.
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This paper will discuss the design, fabrication, and testing of a Poly(dimethylsiloxane) (PDMS) microfluidic pump. PDMS is commonly described as a soft polymer with very appealing chemical and physical properties such as optical transparency, low permeability to water, elasticity, low electrical conductivity, and flexible surface chemistry. PDMS microfluidic device fabrication is done easily with the use of soft lithography and rapid prototyping. PDMS microfluidic devices make it easier to integrate components and interface devices with particular users, than using typically harder materials such as glass and silicon. Fabrication and design of single and multilayer PDMS microfluidic devices is much easier and straightforward than traditional methods. A novel design of a PDMS micropump with multiple vibrating membranes has been developed for application in drug delivery and molecule sorting. The PDMS micropump consists of three nozzle/diffuser elements with vibrating membranes, which are used to create pressure difference in the pump chamber. Preliminary analysis of the fluidic characteristics of the micropump was analyzed with ANSYS to investigate the transient responses of fluid velocity, pressure distributions, and flow rate during the operating cycle of the micropump. The design simulation results showed that the movement of the wall membranes combined with rectification behavior of three nozzle/diffuser elements can minimize back flow and improve net flow in one direction. To prove that the theoretical design is valid, the fabrication and testing process of the micropump has been carried out and completed. This paper will discuss in depth the design, fabrication, and testing of the PDMS micropump.
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Hu, Chong. "Novel polymer-based microfluidic devices: fabrication and application for controllable reactions." HKBU Institutional Repository, 2018. https://repository.hkbu.edu.hk/etd_oa/499.
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The present thesis includes a series of studies on microfluidic technology from novel microfabrication methods in polymers to diverse microfluidic applications. Specifically, this study focuses on some key issues in microfluidics, regarding the development of microfluidic fabrication strategy, material selection for microfabrication, and applications, in particularly controllable reactions of novel polymer-based microfluidic devices. We have developed novel methods, which hold completely different idea/ concept with conventional approaches', for fabrication of microfluidic chips with polymer materials. While for the microfluidic applications, the thesis exhibits cell perfusion experiments with freestanding 3D microchannels made of alginate hydrogel, convenient and sensitive lead(Ⅱ) ions detection on a plastic membrane microfluidic chip which was fabricated by the proposed novel one-step strategy, as well as and microfluidic controllable synthesis of enzyme-embedded metal-organic frameworks in a laminar flow;In the first part, we proposed an inside-out fabrication strategy using a copper scaffold as the sacrificial template to create freestanding 3D microvascular structures containing branched tubular networks with alginate hydrogel. The microvascular structures produced with this method are strong enough to allow handling, biocompatible for cell culture, appropriately porous to allow diffusion of small molecules, while sufficiently dense to prevent blocking of channels when embedded in various types of gels. In addition, other materials and biomolecules could be pre-loaded in our hydrogel tubular networks by mixing them with alginate solution, and the thickness of tubule wall is tunable. Compared to other potential strategies of fabricating free-standing gel channel networks, our method is parallel processing using an industrially mass-producible template, making our method rapid, low-cost and scalable. We demonstrated cell culture in a nutrition gradient based on a microfluidic diffusion device made of agar, a hydrogel traditionally hard to microfabricate, by embedding the synthesized tubules into the agar gel. In this way, the freestanding hydrogel vascular network we produced is a universal functional unit that can be integrated with other gel-based devices to build up the supporting matrix for 3D cell culture outside the hydrogel vascular structure; allowing great convenience and flexibility 3D culture. The method is readily implementable to have broad applications in biomedicine and biology, such as vascular tissue regeneration, drug discovery, and delivery system in 3D culture.;The second part, we developed a one-step method to mass produce microfluidic chip with thermal plastic membranes. We used a perfluoropolymer perfluoroalkoxy (often called Teflon PFA) negative mold, which is very nonsticky and has ultrahigh melting point, as solid stamp to thermal-bond two pieces of plastic membranes, low density polyethylene (LDPE) and polyethylene terephthalate (PET) coated with ethylene-vinyl acetate copolymer (EVA), which have different coefficients of thermal expansion. During the short period of contact with the heated Teflon stamp, the pressed area of the membranes permanently bonded, while the LDPE membrane spontaneously rose up at the area not pressed, forming microchannels automatically. These two regions were clearly distinguishable even at micrometer scale so that we were able to fabricate microchannels with width down to 50 microns. By using thermal-bonding, the pattern of Teflon mold will be transferred to the plastic membrane forming channels while two membranes will be bonded at the same time. The method enables generation of microchannels and bonding process to accomplish in a single step without sophisticated instruments. One Teflon mold can be used to mass replicate many plastic membrane chips in a short time because each round needs only a few seconds. Our method can fabricate a plastic microfluidic chip rapidly (within 12 seconds per piece) at an extremely low price (less than 0.02{dollar} per piece). We also showed some identical microfluidic manipulations with the flexible plastic membrane chips including droplet formation, microfluidic capillary electrophoresis and squeezing-pump for quantitative injection. In addition, we demonstrated convenient on-chip detection of lead ion by a peristaltic-pumping design, as an example of the applications of the plastic membrane chips in resource-limited environment. Due to the fast production method and low-cost of plastic materials, this one-step method will hopefully lead to new opportunities for the commercial implementations of microfluidic technologies.;Finally, on the basis of preliminary study of microfluidic laminar flow synthesis of MOFs in aqueous system in Chapter 4, we successfully synthesized and investigated formation of enzyme-embedded metal-organic frameworks (MOFs) in a continuous laminar flow on a microfluidic chip. Resultant enzyme-MOF composites displayed higher enzymatic activity than enzyme-MOF composites from bulk solution synthesis. A possible reason was that the precisely controlled and yet changeable reaction conditions such as reaction time and diffusive mixing of reagents allowed the fast reaction to be isolated into controllable processes and studied with predesigned yet changing conditions. This, in return, led to distinct morphological characteristics and activities of the enzyme-MOF composites compared to those from bulk synthesis. The results indicated that the highest activity of enzyme-MOF composites was obtained when metal ions and organic ligands were first gradually mixed within a few seconds before enzyme molecules joined the gradual mixing process. We found that the crystallinity degree of as-produced enzyme-MOF composites was reduced via the microfluidic flow synthesis, containing more structural defects compared to those with high degree of crystallinity from bulk synthesis. The reduced crystallinity allowed more effective approaching of substrates with enzyme embedded in composites and therefore an increased enzyme activity compared to enzyme-MOF composites from bulk synthesis. We further demonstrated that enzyme-MOF composites showed enhanced stability against elevated temperature and protease digestion compared with free enzymes, allowing their wider utility in biotechnology.