Dissertations / Theses on the topic 'Encapsulation technology'

Previous studies indicated that emulsions with nano-sized droplets or nano-emulsions possess anti-microbial activity. The microstructure of water-in-oil-in-water (W1/O/W2) emulsions present interest for microbial encapsulation in food, cosmetic and pharmaceutical applications. Therefore microbe-emulsion interactions need to be characterised in order to fully explore the potential of such applications. This thesis investigated the effect of nano-emulsions on bacteria as well as W1/O/W2 emulsion feasibility for encapsulation and triggered release (altering osmotic pressure) of bacteria and in real life application by incorporating in set-style yogurt model system for protection of probiotics were investigated. Exposure of bacterial cells to nano-emulsions was found to have no significant effect on the survival or growth bacteria and cell membrane integrity was not compromised. Bacteria had no effect on the stability of nano- and double emulsions. The release of bacteria form W1/O/W2 emulsion occurred due to the bursting of the oil globules independent of diffusion mechanisms and be controlled by altering the structure of W1/O/W2 emulsion. W1/O/W2 emulsion had a significant effect on texture and physicochemical properties of yogurt but no effect on bacterial growth kinetics while probiotics maintained high viability at the end of the fermentation. In summary, this thesis demonstrates the feasibility and applicability of W1/O/W2 emulsion for the encapsulation of microbial cells for the purpose of their protection and triggered release. The results of this thesis can be used in the formulation of better probiotic products, segregation, protection, and release of microbial cells during fermentation as well as for in vivo delivery of fermentation.

Immunoisolation of pancreatic beta cells is a promising approach for the treatment of type I diabetes. In this thesis, a vibrating nozzle technology was utilised to reproducibly generate 1% alginate microparticles with an average diameter of 200 μm±19 S.D. This technology further enabled the application of fluidised bed bioreactor owing to high uniformity of particles, an important parameter for achieving homogeneous fluidisation. Experimental data collected from the cultivation of cells in fluidised culture was shown to provide a promising solution for handling encapsulated cells from manufacturing phase to clinical sites, which is currently a challenging issue for cell-based therapies. A reduction in beta cells insulin-secreting ability was observed after two weeks of static culture. This problem was addressed by investigating a 3- dimentional culturing technique and a novel polyelectrolyte multilayer (PEM) coating approach. Concave agarose micro-wells were used to culture robust pancreatic beta cell spheroids that enhanced cell-cell contact. Additionally, the novel PEM coating using Ca2+ pre- conditioning improved cell function while providing immunoisolation from cytokines, and reducing the total volume of the graft. This work presented an effective immunoisolation and culturing system to improve cells survival rate, which hopes to bring a closer step towards therapeutic transplantation.

Polymer flooding is one of the most common chemical EOR techniques used in EOR projects worldwide. However, field applications of polymer flooding are usually limited by the cost of polymer and its considerable loss during the injection. The injectivity and efficiency of polymer flooding are significantly affected by polymer degradation, polymer retention, and high velocity near the wellbore. A function of nanoparticles—encapsulation—can be used to reduce these adverse impacts. Encapsulating polymer in the nanocapsules can isolate polymer from the environment and from impact near the wellbore for a designated releasing time, thereby reducing the impact near the wellbore. To explore the effect of nanocapsules on polymer injection, numerical models for polymer flooding were applied to test the decrease of injection pressure between encapsulated polymer injection and pure polymer injection, under different values of simulation parameters. The viscosity model was then integrated into an in-house grid-based simulator to simulate the transport of capsules and released polymers in the formation. The result indicates that for an engineered releasing time, encapsulating polymer in the nanocapsules can prevent polymer from contacting the environment near the wellbore, thus reducing the injectivity loss occurring near the wellbore and transporting polymers to further areas in the reservoirs.

There is a clear need for the development of novel materials for bone regeneration. There is, however, with the exception of poly-(methyl methacrylate) a lack of mouldable polymeric fillers for irregular bone defects. In this thesis, we investigate the production of a new bone graft replacement combining magnetite nanoparticles with polycaprolactone (PCL) to produce a material that can soften in response to the application of an alternating magnetic field. The magnetite nanoparticles were synthesized by a non-surfactant method and then emulsified with PCL. Particle size analysis using light scattering showed that the size distributions of magnetite nanoparticles were influenced by acid concentration and mixing conditions. In contrast, the size of the PCL particles were not strongly related to the mixing conditions, but was influence by the stabilizer used during emulsification. The magnetite nanoparticles showed superparamagnetic behaviour when analysed using SQUID. In the thermal test, magnetite nanoparticles display smooth curves both in the heating and cooling processes and do not shows significant heat loss. Scanning electron microscopy and chemical analysis showed that the magnetite nanoparticles were evenly distributed through the polymer matrix and could be caused to melt following an appropriate external magnetic stimulus. It was demonstrated that magnetite containing microspheres could successful be used for the encapsulation and delivery of antibiotics at a dose which was sufficient to be lethal to E. coli.

There is an increasing demand from the pharmaceutical and food industries for new probiotic products. Some yeast strains offer probiotic benefits, but it has not been possible to formulate them successfully into a tablet dosage form. Direct compression is regarded as the best technique for producing tablets containing dried yeast, however, the main challenge of tabletting a powder mixture containing yeast granules is the mechanical sensitivity of the cells. The objective of this work was to develop a rigid yeast tablet containing adequate numbers of viable yeast cells by optimizing the formulation to allow a relatively low compaction force to be used. In addition the mechanical properties of primary particles and granules were determined as an attempt to predict the compaction behaviour during tabletting. A tablet formulation was developed which exhibited tablets of an acceptable tensile strength. These tablets were further tested for friability, dissolution and storage stability to ensure it is fit for consumer use.

Moromi fermentation is an essential part of soy sauce production. This thesis aimed to characterize and control the growth and interaction of two predominant microorganisms, Tetragenococcus halophilus and Zygosaccharomyces rouxii for enhancing the aroma development during moromi fermentation. Antagonism was observed between T. halophilus and Z. rouxii, regardless of the inoculation sequence. However, sequential inoculation of Z. rouxii resulted in more complex aroma profile than simultaneous inoculation. To eliminate antagonism, chitosan-coated alginate and water-oil-water (W1/O/W2) double emulsions (DEs) were tested for their ability to encapsulate Z. rouxii and stability in high NaCl solutions. Alginate was unstable in high NaCl solutions and chitosan exhibited undesirable antimicrobial activity towards Z. rouxii. DEs minimized the antagonism between T. halophilus and Z. rouxii, by segregation in the external W2 and internal W1 phase, respectively. Physicochemical changes in the fermentation medium indicated that DEs affected microbial growth and cell physiology, contributing to the elimination of antagonism. The destabilization of DEs over 30-day storage depended on glucose concentration in W2, which indicated a possibility of sustained release mechanism of Z. rouxii into the moromi. Furthermore, the application of DEs was tested in a moromi model, formulated with reduced NaCl and/or substitution with KCl. DEs resulted in moromi with similar microbiological and aroma profile to that of high-salt. Overall, this thesis demonstrates the potential of DE for delivering mixed cultures in moromi fermentation, which could be applicable in any fermentation process where multiple species are required to act sequentially.

There is increasing clinical need for bone substitutes because of the limited supply of autogenous tissue, and the significance of inherited or other bone diseases. The ultimate aim of this study was to form calcium phosphate (CaP) based matrices as bone grafts for medical applications. Amongst CaP based materials, CaP gels made by the sol-gel process have attracted much interest since they can be processed at room temperature allowing the incorporation of environmentally sensitive molecules such as growth factors. CaP gels can be engineered by changing process conditions. There is little previous work however on the effect of drying regimes on the CaP materials formed using the sol-gel process. The objectives of this research were to investigate the influence of drying conditions on the physicochemical properties of CaP gels and the effect of the resultant structures of CaP gels on the function of the incorporated therapeutic molecules. In addition, surface modification of the CaP gels was investigated as a means to enhance biological interaction and also a potential way of creating primary bonds between apatite crystals enabling mechanical reinforcement of the material, which is currently too weak to bear load. This work has confirmed that different drying regimes have a significant influence on the formation of the gel pore structure, with the storage of gel in humid conditions, enabling reprecipitation of an apatitic phase. This variation in pore structure has a significant influence on the catalytic of encapsulated enzymes. In addition, the pH fluctuation of CaP based matrices during processing determines the activity of biomolecules after incorporation. It has also been shown that it is possible to form thiol functional groups on the surface of CaP gels, which could be used in future for mechanical reinforcement or for the attachment of biological moieties.

The design and development of smart colloidal structures intended for molecular encapsulation and delivery of functional molecules is an area of intense academic and industrial interest. A major part of this area is focussed on stimulating molecular release using an external stimulus such as pH or temperature. Whilst controlled delivery technologies are a mainstay of the pharmaceutical industry, aligned industries that utilise formulation to deliver functional molecules are also targets for encapsulation technology implementation. This can be a key driver for ameliorating competition from generic manufacturers, as any resulting can patent protection can be applied to the formulation. Current approaches in colloidal encapsulation and molecular delivery have mainly been concerned with encasing and subsequent release of a single functional molecule. However, there is interest in being able to structure two or more functional molecules within a “simple” emulsion microstructure for dual release over different timescales. Within colloid science, emulsions offer significant potential in this area due to the potential for compartmentalisation within the multiphase components. This thesis focuses on the design and development of Pickering emulsions structured with two actives segregated within their microstructure. This was achieved through the fabrication of colloidal Pickering particles designed with the dual purpose of being both emulsion stabilisers and molecular carriers. The work ultimately combines colloid structure design, development and characterisation with molecular encapsulation and release studies.

An underused feature of the MiniZinc language for modelling combinatorial problems is that its models can be parsed, analysed, and modified; however, this could enable modellers to improve their modelsin novel ways. The auto-tabling tool of Jip J. Dekker allows modellers to annotate a predicate definition in a MiniZinc model for automatic presolving that tabulates the solutions to the predicate within anextensional constraint and replaces the predicate definition with it.This is a well-known and powerful way to reformulate a constraint model, and this auto-tabling tool eliminates a lot of the hassle that comes with doing this reformulation manually. A part of a model that can be presolved is called a submodel, and a submodel can been capsulated within a predicate definition in MiniZinc. However, there are still some unanswered, unvisited, but important questions: What are (and how do we find) the submodels that yield the best performance improvement when presolved, and is there a systematic way of identifying, ranking, and encapsulating submodels of a MiniZincmodel that can be automated? In this thesis, we present concepts and an implemented tool that answer all the aforesaid questions, and show that the automatically generated results of the tool are similar to those created manually.

In the future the demand for ethanol is expected to increase greatly due to the rising energy requirements in the world. Lignocellulosic materials are a suitable and potentially cheap feedstock for sustainable production of fuel ethanol, since vast quantities of agricultural and forest residues are available in many countries. However, there are several problems involved in the utilization of lignocellulosic raw materials as sugar source. The most common way of releasing the simple sugars in the material is by dilute acid hydrolysis. This procedure is relatively simple and cheap, but in addition to the sugars it creates inhibitory compounds. These inhibitors make it very hard for the yeast to ferment the hydrolyzate and detoxification is often necessary. One way to overcome this problem is to encapsulate the yeast. Encapsulation is an attractive method since it improves the cells stability and inhibitor tolerance, increases the biomass amount inside the reactor, and decreases the cost of cell recovery, recycling and downstream processing. However, the method does not yet permit long-term cultivation since the capsules used so far are not robust enough. Therefore more studies have to be conducted in order to find methods which produce mechanically robust capsules. The main goal of this paper is to find a suitable method to produce robust capsules using different concentration of the chemicals at different pH and also implementing some modifications such as addition of cross-linkers in preparation procedure. In this paper comparison of three different encapsulation techniques were studied based on the mechanical robustness of the capsules. The three different techniques were calcium mineralized alginate-chitosan capsules, alginate capsules coated with 2% chitosan (2% AC) and genipin crosslinked alginate-chitosan (GCAC) capsules. The results indicate that GCAC capsules are most robust and were good enough for prolonged use since most of the capsules were not deformed in mechanical strength test. There were slight differences in the diameter and membrane thickness before and after swelling. No negative influence was observed on the yeast growth when applying the cross-linker. The results of this study will hopefully add valuable information and helps in further studies using other cross-linkers to prepare robust capsules.
Program: Industrial Biotechnology

Robot controller cabinets are specified with interfaces which make it possible to connect different modules for completing numerous tasks that are chosen for the robot manipulators. Different interfaces will be utilized depend on the kind of tasks and settings that are chosen. Thus not every interface will be put into use in a controller cabinet, some are left behind. In order to fulfill the encapsulation standards of electrical enclosures, the unoccupied interfaces are covered and sealed with on-screwed cover plates and gaskets during the assembly of the cabinet. However, a new method for encapsulation hope to be investigated and introduced to improve the current solution with respect to the encapsulation requirements from ABB.  The introduced new solution is a knockout concept. The detailed design is investigated with the help of finite element analysis with the explicit dynamics method used for simulating the punching processes of the knockout designs. Where three different design variables are put into consideration for finding the most optimum knockout design.  The results show that, for the particular steel plate provided by ABB, a V-grooved knockout design with a grooving angle of 90 degrees and an unaffected thickness of 0.1 mm has the best performance in terms of smoothness at edges and the amount of plastic strain occurred in the material.  Traditional manufacturing methods to manufacture the obtained knockout design appear to be extremely time consuming and thus not profitable for mass production. However, a type of fairly recent developed grooving machines, the so called V-grooving machine, is believed to be able to solve the manufacturing problem.
Robot styrskåp är specificerad med mängder gränssnitt vilket gör det möjligt för anslutning av olika moduler till att kunna fullborda de uppgifterna valda för robot manipulatorerna. Olika gränssnitt utnyttjas beroende på den typ av arbetsuppgift och inställningar valda just för den. Därför kommer inte alla gränssnitt att kunna tas i bruk i ett styrskåp, vissa lämnas kvar. För att kunna uppfylla inkapslingsstandarden för elektriska kapslingar är dessa obesatta gränssnitt täckt och förseglat med påskruvad täckplåtar och packningar under montering av styrskåp. En ny inkapslingsmetod hoppas att kunna utredas och introduceras till att förbättra den nuvarande lösningen med avseende på de inkapslingskraven från ABB.  Den introducerade lösningen är ett knockout koncept. En detaljerad konstruktion undersöks med hjälp av finita element analys med explicit dynamik som grunden till att simulera knockout processer. Där tre olika design parametrar tas i beaktande för att hitta den mest optimala knockout konstruktionen.  Resultaten visar sig att, för den här särskilda stålplåten som tillhandahålls av ABB, en V-spårad knockout konstruktion med en spårvinkel på 90 grader och en tjocklek på 0.1 mm har den mest tillfredställande prestandan med avseende på jämnhet, d.v.s. reduceringen av vassa kanter, och mängder av plastiska töjningar som inträffas i materialet efter knockout processen.  Traditionella tillverkningsmetoder till att tillverka en sådan knockout konstruktion visar sig vara väldigt tidsödande och anses därför inte vara lönsamt för massproduktion. Emellertid upptäcks det en typ av relativt nyutvecklad spårmaskin, så kallad V-grooving machine, som tros att kunna lösa tillverkningsproblemet.

Encapsulation technology has been widely researched and applied to different industry sectors. There are vast examples of encapsulation for controlled release of hydrophilic or hydrophobic ingredients to the target place. However, it is still difficult to encapsulate the small water-soluble salts or molecules, achieving long-term sustained release or even no release in water. Herein, a novel type of organic-inorganic composite solid microsphere, comprised of polystyrene sulfonate and silica was developed here to achieve a sustained release of K+ ions in aqueous environment for over 48 hours. Furthermore, a novel type of melamine formaldehyde (MF) based has been developed to encapsulate KCl and allura red, showing a sustained release of KCl and allura red for 12 h and > 10 days in water, respectively. Finally, a novel formulation for encapsulation of KCl and allura red has been developed based on the formation of melamine formaldehydeoctadecyltrichlorosilane- melamine formaldehyde (MOM) microcapsules, achieving no release in aqueous environment for 1 month. It is a breakthrough to prevent the leakage of small water soluble ingredients from the carrier, which is of great significance for their long-term storage until they are delivered to a target place via triggered release in many applications.

Efficacy of subcritical water in the recovery of the polyphenolic compounds from the apple pomace using a batch reactor system at 100-bar over a temperature range of 100-200oC for a residence time of 10–30 minutes was investigated. Organic solvent extractions using acetone and ethanol were carried out to serve as a baseline for comparison with the subcritical water extraction. Subcritical water was efficient in solubilising the apple pomace, and extracting polyphenolics with high antioxidant activity. Maximum solubilisation of the apple pomace was achieved at 145oC for 30 minutes and total phenolic content and antioxidant activity at 200oC. Solubilisation, ORAC activity and total phenolic content of subcritical water extract were 28.20g/100g DW, 99285μmol TE/g DW and 49.86mg/g GAE DW of apple pomace respectively, compared to 19.20g/100g DW, 6260.27 μmol TE/g DW and 21.70mg/g GAE DW of acetone extracts of apple pomace respectively. Protocatechuic aldehyde was identified for the first time only in the subcritical water extract and to date has not been identified in solvent extracts of cider apple pomace. Encapsulation of polyphenolic s of subcritical water extract using spray drying was explored. Particles/powders formed were derived from the naturally occurring carbohydrate polymers co-extracted with polyphenols. Addition of HPβ-Cyclodextrins (SWE+ HPβ-CD) to the directly encapsulated powder (SWE) significantly reduced hygroscopicity and improved antioxidant activity.

Les microsystèmes nécessitent généralement d'être insérés dans un environnement parfaitement contrôlé afin de permettre d'une part, un mode de fonctionnement optimum (vide par exemple lorsque le facteur de qualité doit être élevé) ou d'autre part, de pouvoir relier ses caractéristiques de sortie aux conditions de fonctionnement. Il est donc important de pouvoir les placer dans un boitier de protection parfaitement adapté. Avant cela, le dispositif doit être découpé dans le substrat de silicium. Cette étape de découpe est critique car elle nécessite l'utilisation d'un jet de fluide sur la surface pouvant entrainer l'endommagement partiel ou complet du dispositif ou encore provoquer le collage de la partie désolidarisée du substrat. Nous avons imaginé un procédé original de report de film sur le dispositif afin d'assurer la protection du MEMS durant cette étape de découpe. Ce procédé utilise la technologie de transfert, à savoir que les capots protecteurs sont élaborés sur un substrat spécifique puis désolidarisé de ce substrat pour venir recouvrir le substrat recouvert de structures MEMS. Plus largement, ce procédé universel permet de réaliser un très grand choix de microdispositifs (jauges Pirani par exemple). Ainsi, ce procédé a été entièrement qualifié pour des applications de packaging puis étendu au report de microstructures
Generally microsystems require to be inserted in an environment perfectly controlled in order to allow an optimum functioning process (vacuum for example when the quality factor must be high) or to be able to connect its exit characteristics to the operating conditions. It is thus important to be able to place them in a perfectly adapted packaging of protection. Before that, the device must be cut out in the silicon substrate. This cutting step is critical because it requires the use of a fluid jet on surface which can involve the partial or complete damage device or cause the sticking effect of microdevices on the substrate. We imagined an original film transfer process on the device in order to ensure the MEMS protection during this cutting step. This process uses the transfer technology, namely that micro-caps are elaborate on a specific substrate then separated of this substrate to protect to micro-structures on the final substrate. More largely, this universal process makes it possible to carry out a very great choice of microdevices (Pirani gauges for example). Thus, this process was fully qualified for packaging applications then extended to microstructures transfer

In novel drug delivery system, the encapsulation of therapeutic cells in microparticles has great promises for the treatment of a range of health con- ditions. Therefore, the encapsulation material and technology are of great importance to the validity and efficiency of the advanced medical therapy. Several unsolved challenges in regards to versatile microparticle synthesis ma- terials and methods form the main obstacle for a translation of novel cell therapy concepts from research to clinical practice. Thiol-ene based polymer systems have emerged and gained great popular- ity in material development in general and in biomedical applications specif- ically. The thiol-ene platform is broad and therefore of interest for a variety of applications. At the same time, many aspects of this material platform are largely unexplored, for example material and manufacturing technology developments for microfluidic applications . In this Ph.D. thesis, thiol-ene materials are explored for use in cell encap- sulation. The marriage of these two technology fields breeds the possibility for a novel microfluidic cell encapsulation approach using a novel encapsulation material. To this end, several new manufacturing technologies for thiol-ene and thiol-ene-epoxy droplet microfluidic devices were developed. Moreover, core-shell microparticle synthesis for cell encapsulation based on a novel co- synthesis concept using a thiol-ene based material was developed and inves- tigated. Finally, a thiol-ene-epoxy system was also used for the formation of microwells and microchannels that improve protein analysis on microarrays. The first part of the thesis presents the background and state-of-the-art technologies in regards to cell therapy, microfluidics, and thiol-ene based ma- terials. In the second part of the thesis, a novel manufacturing approach of thiol-ene-epoxy material as well as core-shell particle co-synthesis in micro- fluidics using thiol-ene based material are presented and characterized. The third part of the thesis presents the cell viability studies of encapsulated cells using the novel encapsulation material and method. In the final part of the thesis, two applications of thiol-ene-epoxy gaskets for protein detection mi- croarrays are presented.
Inkapsling av levande celler i mikrokapslar för terapeutiska ändamål är mycket lovande för frmatida behandling av många olika sjukdomar. Emeller- tid är en behandlings effektivitet i hög grad beroende av vilka material som används för inkapsling och vilken teknisk lösning som används för att ska- pa mikrokapslarna. För närvarande återstår det många utmaningar för att omvandla grundforskningresultat till klinisk verklighet, vilken kräver mer än- damålsenliga tillvägagångssätt för att tillverka mikrokapslar i material som är kompatibla med användningsområdena. De senaste åren har tiol-en baserade polymerer har blivit mycket använda för materialutveckling i stort och för biomedicinska tillämpningar i synnerhet. Med tiol-en kemi kan en mycket stor mängd helt olika syntetiska material framställas, vilket gör tiol-ener intressanta för en mängd applikationer. För närvarande är dock mycket inom denna materialklass outforskat, t.ex. inom material och tillverkningmetodik för mikrofluidiktillämpningar. I denna avhandling används tiol-ener för cellinkapsling. Sammanslagning av dessa teknologier möjliggör en ny typ av cellinkapsling med nya materi- alegenskaper. En mängd olika tillverkningssätt där tiol-en eller tiol-en-epoxi används för droplet-mikrofluidiksystem utvecklades. Core-shell mikrokapsel- syntes för cell-inkapsling baserat på en ny metod för samtidig syntes av både core och shell utvecklades och karaktäriserades. Slutligen utvecklades ett tiol- en-epoxi system för enkel integrering med proteinmikroarrayer på objektsglas. I avhandlingens första del presenteras bakgrund och dagens bästa teknolo- gier för terapeutisk cellinkapsling, mikrofluidik och tiol-en baserade material. I avhandlingens andra del presenteras en ny tillverkningsmetod för mikro- strukturerade tiol-en-epoxi artiklar och samtidig syntes av core och shell för mikrokapslar med användande av mikrofluidik. I den tredje delen presenteras cellöverlevandsstudier för de celler som inkapslats med de nya materialen och de nyutvecklade metoderna. I den avslutande delen beskrivs två specifika fall där tiol-en-epoxi komponenter används för proteindetektion och mikroarrayer.

QC 20171122

Les micro-dispositifs comportant des structures libérées et mobiles sont d'une part très sensibles aux variations de leur environnement de travail, et d'autre part très fragiles mécaniquement. L'étape de découpe du substrat en plusieurs puces est extrêmement agressive et peut entrainer la destruction totale des micro-dispositifs. L'encapsulation avant la découpe va alors prémunir les micro-composants lors de cette étape critique et continuer à garantir leur bon fonctionnement tout au long de leur utilisation en conservant la stabilité et la fiabilité de leur performance. Le conditionnement doit en outre interfacer les micro-dispositifs encapsulés avec le monde macroscopique en vue de leur utilisation. De nombreux procédés de fabrication ont déjà été développés pour l'élaboration d'un conditionnement. C'est le cas de l'encapsulation puce par puce, substrat - substrat, par couche sacrificielle par exemple. Ils sont toutefois très contraignants (encombrement, compatibilité, coût, ...). Nous avons étudié, au cours de cette thèse, un procédé innovant de conditionnement hermétique par transfert de film utilisant une couche à adhésion contrôlée. Cette technologie consiste à élaborer des capots protecteurs sur le substrat moule puis à les reporter collectivement pour encapsuler les micro-dispositifs. Ce procédé est totalement compatible avec un interfaçage électrique de composant qui traverse les cordons de scellement ou le capot. Ce procédé nécessite la maîtrise de la croissance de divers films (C, CxFy, Ni, AlN, parylène, BCB, Au-In) et permet d'obtenir des boitiers étanches, hermétiques et robustes qui devraient très rapidement pouvoir être utilisés pour le conditionnement de MEMS.

The Pleurotus genus can use by-products of agri-food industry as substrates to develop its edible fruiting body. Pleurotus ostreatus, which is the most cultivated specie of Pleurotus, has high nutritional and nutraceutical properties; in particular, it is a source of vitamin D2 and fiber named β-glucans. However, food uses of this mushroom are limited because of the lack of value-added applications. The overall aim of this PhD thesis was to develop functional ingredients from P. ostreatus biomass. Specific goals were: a) development of a food application and production of a powdered ingredient with a target amount of vitamin D2; b) encapsulation of an oxidizable target using P. ostreatus β-glucans as antioxidant and emulsifying agent. The results showed that using an adequate concentration of dehydrated and milled P. ostreatus for the development of new food applications could help against the increasing vitamin D2 deficiency among specific groups of populations. To enhance the level of vitamin D2 in P. ostreatus, a combined process of UV irradiation and air-drying was applied, and a new powdered ingredient with a target amount of vitamin D2 was obtained. The kinetics of vitamin D2 degradation in P. ostreatus powder was studied as a function of water activity and temperature to predict its stability during storage. The kinetics data obtained can be used as a starting point to project the best formulation strategy to deliver vitamin D2 with functional foods. Since there is a gap of knowledge about the effect of UV irradiation on mushroom bioactive compounds, the antioxidant and antiglycation activities of Agaricus bisporus and P. ostreatus were investigated and the results pointed out that UV irradiation reduced the antioxidant activity, but not the antiglycation properties. Two different β-glucan-rich extracts were obtained from P. ostreatus; after characterization, they were used to stabilized oil-in-water emulsions. Their stability was checked through variation of oil droplets size distribution over time, in order to find the best formulations suitable for further encapsulation, which was carried out using spray drying technique. After production, the powders were analyzed for the particle morphology and in terms of oil protection against oxidation. Results showed that P. ostreatus extracts provided good emulsifying properties and it allowed excellent protection of α-tocopherol and polyunsaturated fatty acids against oxidation. The effects of the P. ostreatus extracts was tested during in vitro digestion; samples underwent partial aggregation, but the oil droplets were still fairly stable, and α-tocopherol degradation was slower in presence of β-glucans up to the beginning of intestinal phase. The protection against oxidation was also studied during 15 days of accelerated storage; β-glucans improved the oxidative stability of the powders, compared to common emulsifier with no inherent bioactivity. In conclusion, it is evident that P. ostreatus and its compounds can be exploited as sustainable food ingredients to deal with the requirements of populations with endemic nutritional deficiencies and to stabilize oxidizable target during encapsulation process, in vitro digestion and storage.

Block copolymer nanoparticles (NPs) have gained great attention among researcher for various medical application mainly due to their extraordinary optical, chemical, and biological properties. The current thesis presents design of multifunctional polymeric NPs for imaging and drug delivery system (DDS) with an in-vitro study of their participation in drug release and cell viability. The NPs were synthesized using reversible addition chain fragmentation transfer (RAFT)-mediated emulsion polymerization via polymerization induce self-assembly (PISA) approach. The environment-friendly emulsion polymerization process of n-buytl acrylate (n-BA) in water is highly efficient. The process produced uniform NPs which would have control over the particle size and molecular weight of the compound. Herein we report a novel simultaneous encapsulation of camptothecin (CPT) and Nile red (NR) into poly(ethylene glycol) methyl ether methacrylate-co-N-hydroxyethyl acrylamide-b-poly n-buytlacrylate (PEGA-co-HEAA)-b-P(n-BA) during the particles formation with a small particle size of 66 nm, high conversion ~80% and encapsulation efficiency of ~50%. The In vitro drug release of the CPT from the NPs exhibited an initial burst (70-80%) within 6h. cell viability was evaluated for the NPs against RAW 264.7 cell line, which indicated the designed NPs are biocompatible and not toxic.

Mise au point d'un systeme de vectorisation de l'antibiotique polyenique amphotericine afin d'augmenter sa toxicite selective, en nous interessant aux vesicules soniquees unilamellaires. L'utilisation de methodes spectroscopiques a permis de quantifier le taux d'antibiotique fixe aux vesicules dans differentes preparations liposomales

Les prothèses neuronales implantables offrent de nos jours une réelle opportunité pour restaurer des fonctions perdues par des patients atteints de lésions cérébrales ou de la moelle épinière, en associant un canal non-musculaire au cerveau ce qui permet la connexion de machines au système nerveux. La fiabilité sur le long terme de ces dispositifs, se présentant sous la forme d'électrodes implantables, est un facteur crucial pour envisager des applications dans le domaine des interfaces cerveau-machine. Cependant, les électrodes actuelles pour l'enregistrement et la stimulation se détériorent en quelques mois voire quelques semaines. Ce défaut de fiabilité sur le long terme, principalement lié à une réaction chronique contre un corps étranger, est induit au départ par le traumatisme consécutif à l'insertion du dispositif et s'aggrave ensuite, durant les mouvements du cerveau, à cause des propriétés mécaniques inadaptées de l'électrode par rapport à celles du tissu. Au cours du temps, l'ensemble de ces facteurs inflammatoires conduit à l'encapsulation de l'électrode par une couche isolante de cellules réactives détériorant ainsi la qualité de l'interface entre le dispositif implanté et le tissu cérébral. Pour s'affranchir de ce phénomène, la biocompatibilité des matériaux et des procédés, ainsi que les propriétés mécaniques de l'électrode doivent être pris en considération. Durant cette thèse, nous avons abordé la question en développant un procédé de fabrication simple pour réaliser des dispositifs implantables souples en parylène. Les électrodes flexibles ainsi obtenues sont totalement biocompatibles et leur compliance est adaptée à celle du tissu cérébral ce qui limite fortement la réaction inflammatoire occasionnée par les mouvements du cerveau. Après avoir optimisé le procédé de fabrication, nous avons focalisé notre étude sur les performances du dispositif et sa stabilité. L'utilisation d'une grande densité d'électrodes micrométriques, avec un diamètre de 10 à 50 µm, permet de localiser les zones d'enregistrement en rendant possible, par exemple, la conversion d'un ensemble de signaux électrophysiologiques en une commande de mouvement. En contrepartie, la réduction de la taille des électrodes conduit à une augmentation de l'impédance ce qui dégrade la qualité d'enregistrement des signaux. Ici, un polymère conducteur organique, le poly(3,4-ethylenedioxythiophene), PEDOT, a été utilisé pour améliorer les caractéristiques électriques d'enregistrement d'électrodes de petites dimensions. Le PEDOT a été déposé sur la surface des électrodes par électrochimie avec une grande reproductibilité. Des dépôts homogènes avec des conductivités électriques très élevées ont été obtenus en utilisant différents procédés électrochimiques. Grâce à l'augmentation du rapport surface/volume induit par la présence de la couche de PEDOT, une diminution significative de l'impédance de l'électrode (jusqu'à 3 ordres de grandeur) a été obtenue sur une large plage de fréquences. De tests de vieillissement thermique accéléré ont également été effectués sans influence notable sur les propriétés électriques démontrant ainsi la stabilité de la couche de PEDOT durant plusieurs mois. Les dispositifs ainsi obtenus, fabriqués en parylène avec un dépôt de PEDOT sur la surface active des électrodes, ont été testés in vitro et in vivo sur des cerveaux de souris. Un meilleur rapport signal sur bruit a été mesuré durant des enregistrements neuronaux en comparaison avec des résultats obtenus avec des électrodes commerciales. En conclusion, la technologie décrite ici, associant stabilité sur le long terme et faible impédance, a permis d'obtenir des électrodes implantables parfaitement adaptées pour le développement d'interfaces neuronales chroniques
Implantable neural prosthetics devices offer, nowadays, a promising opportunity for the restoration of lost functions in patients affected by brain or spinal cord injury, by providing the brain with a non-muscular channel able to link machines to the nervous system. The long term reliability of these devices constituted by implantable electrodes has emerged as a crucial factor in view of the application in the "brain-machine interface" domain. However, current electrodes for recording or stimulation still fail within months or even weeks. This lack of long-term reliability, mainly related to the chronic foreign body reaction, is induced, at the beginning, by insertion trauma, and then exacerbated as a result of mechanical mismatch between the electrode and the tissue during brain motion. All these inflammatory factors lead, over the time, to the encapsulation of the electrode by an insulating layer of reactive cells thus impacting the quality of the interface between the implanted device and the brain tissue. To overcome this phenomenon, both the biocompatibility of materials and processes, and the mechanical properties of the electrodes have to be considered. During this PhD, we have addressed both issues by developing a simple process to fabricate soft implantable devices fully made of parylene. The resulting flexible electrodes are fully biocompatible and more compliant with the brain tissue thus limiting the inflammatory reaction during brain motions. Once the fabrication process has been completed, our study has been focused on the device performances and stability. The use of high density micrometer electrodes with a diameter ranging from 10 to 50 µm, on one hand, provides more localized recordings and allows converting a series of electrophysiological signals into, for instance, a movement command. On the other hand, as the electrode dimensions decrease, the impedance increases affecting the quality of signal recordings. Here, an organic conductive polymer, the poly(3,4-ethylenedioxythiophene), PEDOT, has been used to improve the recording characteristics of small electrodes. PEDOT was deposited on electrode surfaces by electrochemical deposition with a high reproducibility. Homogeneous coatings with a high electrical conductivity were obtained using various electrochemical routes. Thanks to the increase of the surface to volume ratio provided by the PEDOT coating, a significant lowering of the electrode impedance (up to 3 orders of magnitude) has been obtained over a wide range of frequencies. Thermal accelerated ageing tests were also performed without any significant impact on the electrical properties demonstrating the stability of the PEDOT coatings over several months. The resulting devices, made of parylene with a PEDOT coating on the active surface of electrodes, have been tested in vitro and in vivo in mice brain. An improved signal to noise ratio during neural recording has been measured in comparison to results obtained with commercially available electrodes. In conclusion, the technology described here, combining long-term stability and low impedance, make these implantable electrodes suitable candidates for the development of chronic neural interfaces

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O amido é ideal como material de parede na preparação de sistemas de liberação controlada, é barato e considerado GRAS. O amido está constituído por dois biopolímeros de D-glicose, a amilose e a amilopectina, as quais representam 99 % da matéria seca do grânulo. A amilose tem a capacidade de formar complexos com algumas moléculas hidrofóbicas como flavors e ácidos graxos, os quais são capazes de resistir a variações de pH e temperaturas elevadas, tornando-se interessante para a formulação de sistemas de liberação controlada de nutrientes. O objetivo inicial deste projeto foi a utilização de amilose extraída da mandioca e do amido de milho com alto teor de amilose comercial (Hylon VII, 72% de amilose) com o intuito de encapsular bixina e avaliar a formação de complexos de inclusão de V-amilose, bem como a sua caracterização usando difração de raios X (DRX), calorimetria exploratória de varredura, espectroscopia de infravermelho, microscopia eletrônica de varredura (MEV), cor, teor de bixina encapsulado, ensaios reológicos oscilatórios e capacidade de liberação. Foram estudados os efeitos das condições de processo de encapsulação por precipitação em solução ácida e através do tratamento com ultrassom sobre as interações entre a bixina e o amido. O efeito da proteína de soro de leite sobre o processo de encapsulação por precipitação em solução ácida também foi estudado. Finalmente, foi realizado um estudo de otimização usando a metodologia de superfície de resposta para selecionar as melhores condições em ambos os métodos, maximizando a capacidade de carga interior da matriz de amido. Além disso, pelo fato de que os xerogéis e criogéis de amido têm ganhado interesse na indústria como sistemas para a microencapsulação de compostos bioativos, este trabalho também explora a capacidade da amilose de mandioca para encapsular carotenoides usando essas metodologias. Nesse caso foram usados como moléculas-hóspedes os carotenoides presentes no óleo de abacate, luteína e neoxantina. Os resultados da encapsulação da bixina usando Hylon VII e proteína por precipitação de uma solução ácida mostraram que existe interação entre a proteína de soro de leite, o Hylon VII e a bixina, como foi observado na análise por FT-IR, no entanto, os padrões de difração e a análise por DSC não confirmaram a formação de complexos de inclusão do tipo V-amilose com a bixina. Porém, transições endotérmicas com ponto de fusão em 117,2, 105 e 104 °C foram observadas nas amostras preparadas a 90 °C com 0%, 10% e 20% de proteína, respectivamente. Cabe ressaltar que um aumento no conteúdo de proteína causou uma diminuição na entalpia de fusão desta estrutura, assim como um decréscimo em sua cristalinidade relativa, o qual foi causado provavelmente pela interação entre a bixina e a proteína. No grupo das amostras preparadas a 90 °C, o aumento no conteúdo de proteína resultou em uma tendência a aumentar o conteúdo e bixina encapsulado. Os resultados de FT-IR mostraram que as bandas de absorção associadas com as vibrações do grupo -C=C- desaparecem, indicando restrição da cadeia da bixina na matriz, assim como o aumento da disponibilidade para interagir com a proteína, embora, essas interações pareçam ser poucas a altas temperaturas. Os padrões de liberação da bixina foram afetados pelo conteúdo de proteína e a temperatura usada no processo de encapsulação, resultando em diferentes porcentagens de liberação. Nos ensaios de encapsulação da bixina com ultrassom foi avaliado o efeito do tratamento sobre as interações amido-bixina. Os resultados por DSC e DRX não confirmaram a formação de complexos de inclusão tipo V-amilose, no entanto, a análise por FT-IR indicou que as bandas de absorção do grupo funcional -C=O da bixina desapareceram depois do processo de encapsulação, o que sugere a existência de interação entre a bixina e o amido. Aparentemente esta não foi encapsulada eficientemente dentro da cavidade de amilose, provavelmente pelo seu tamanho molecular. Os espectros mecânicos dos géis formados durante o processo de encapsulação por ultrassom mostraram uma leve variação dos módulos de armazenamento (G’) e de perda (G’’), com G’>G’’, indicando tratar-se de géis fracos. O maior teor de bixina encapsulado no interior da matriz foi obtido com potência de ultrassom de 150 W por 60 minutos de tratamento. As amostras submetidas ao ultrassom foram menos susceptíveis à ação do fluido intestinal simulado, provavelmente devido ao aumento das interações entre a bixina e o amido em comparação à amostra controle. Em ambos os métodos de encapsulação a morfologia das partículas apresentou superfície irregular e erodida, com protrusões provocadas pela agregação de amilose. Através da análise estatística, observou-se que nos dois métodos de preparação todos os fatores tiveram efeito significativo (p<0,05) sobre o teor de bixina, tanto na superfície como no interior da matriz de amido. Na encapsulação por precipitação em meio ácido, o maior teor de bixina na matriz foi encontrado com o tratamento a 90 °C usando amilose de mandioca junto com proteína. De forma geral, com o uso de amilose de mandioca obteve se um maior teor de bixina encapsulado no interior da matriz e este sempre aumentou com o uso de proteína. Em relação ao tratamento com ultrassom, o maior teor de bixina encapsulado no interior da matriz foi alcançado com 2% de Hylon 150 W e 20 minutos de tratamento. A eficiência de encapsulação alcançada variou de 13,1% a 62,1% e de 17,3% a 94,5% usando tratamento com ultrassom e precipitação em meio ácido, respectivamente. As condições ótimas foram de 2% Hylon, 150 W e 20 minutos para o tratamento com ultrassom. Em relação ao método por precipitação em meio ácido foram 2% amilose de mandioca com proteína, a 68 °C. Os resultados obtidos no processo de encapsulação de luteína e neoxantina usando xerogéis e criogéis de amilose de mandioca indicaram que não houve formação de complexos de inclusão do tipo V-amilose. Entanto, os padrões de difração de raios X observados são característicos deste tipo de complexos. Foi observado um leve aumento na capacidade de encapsulação nas amostras retrodegradadas a -18°C e liofilizadas.
The starch is considered safe and cheap, ideal as wall material in the formulation of delivery systems. Starch granule consists of two major types of α-glucans, amylose, and amylopectin, which represent about 99% of dry matter. Amylose and some hydrophobic molecules such as flavors and fatty acids, form amylose inclusion complexes. Amylose complexes resist to variations of pH and elevated temperature, being good candidates for the formulation of nutrient delivery systems. The initial objective of this thesis was to use high-amylose corn starch (Hylon VII, 72 % amylose) and amylose from cassava starch as wall material for the encapsulation of bixin, evaluating the formation of V-amylose inclusion complexes, and performing their characterization by using X-ray diffractometry, FT-IR spectrometry, scanning electron microscopy, oscillatory rheological tests, color, encapsulated bixin content, and release profile. The effects of process parametres used in the methods based on ultrasound treatment and precipitation in acid solution on the interaction between amylose and bixin were studied, as well as the effect of whey protein on the encapsulation process by precipitation in acid solution. The process conditions that would maximize the encapsulate bixin content inside of the starch matrix were determined by using desirability function. In addition, considering that xerogels and cryogels have gained interest as potential systems for microencapsulation of bioactive compounds and the use of silica aerogels as delivery systems has been demonstrated with success, this thesis explores the capacity of amylose from cassava starch to encapsulate carotenoids using these methodologies. In this case, the guest molecules were the carotenoids present in the avocado oil, lutein and neoxanthin. The results of FT-IR indicated that there was an interaction between protein, Hylon, and bixin in the encapsulation process by precipitation in acid medium. However, the diffraction patterns and the DSC analysis indicated no formation of V-amylose complexes. Nevertheless, although the set of samples prepared at 90°C with 0%, 10% e 20% of protein respectively, showed endothermal transitions with a melting point about 117,2º, 105º and 104°C The increase in protein content decreased the melting enthalpy and relative crystallinity, probably due to the interaction between bixin and protein. In the set of samples prepared at 90°C, the increase in protein content led to a tendency to increase the encapsulate bixin content inside the matrix. The FT-IR analysis indicated that adsorption bands associated with the vibration of the group -C=C- disappeared due to the restriction of bixin chain into starch matrix and increase in the availability to interacting with the protein. However, these interactions seem to be fewer at the higher temperature. The bixin delivery patterns were affected by protein content and temperature used in the encapsulation process, resulting in different delivery amounts. In the encapsulation of bixin by ultrasound treatment, the effect of sonication power level on the interaction between starch and bixin was studied, nevertheless, the results of DSC and Xray diffraction indicated no formation of amylose inclusion complex. The FT-IR analysis showed that adsorption bands of the -C=O group in bixin disappeared after the encapsulation process, which confirms the interaction between starch and bixin, in spite of bixin having not be entrapped efficiently inside of the amylose cavity, probably due to its molecular size. Frequency sweep tests of gels formed during ultrasound encapsulation process showed a slight frequency dependence of G’ and G” moduli with G’>G’’, with patterns correponding to weak gels. The highest bixin encapsulated content inside of matrix was reached using the combination of ultrasound power of 150 W and 60 min of treatment. The sonicated samples were less susceptible to action of simulated intestinal fluid, probably due to increases interaction between starch and bixin as compared to control sample. The particle morphology of samples prepared by both methods showed protrusions of aggregates of amylose, as well as irregular and eroded surfaces. Statistical analysis showed that in both methods, all factors had a significant effect (p<0.05) on bixin encapsulated content inside or on the surface of the matrix. In the encapsulation by precipitation in acid solution, the combination of 90 °C using amylose from cassava starch and protein leaded to the highest bixin encapsulated content. In general, amylose from cassava starch encapsulated a greater bixin content inside of matrix compared to Hylon, and the presence of protein increased this effect even more. Regarding ultrasound treatment, the combination of 2% of amylose from Hylon, and 20 min of treatment showed the highest bixin encapsulated content inside of matrix. Encapsulation efficiency ranged from 13.1% to 62.1% and 17.3% to 94.5% using ultrasound treatment and precipitation in acid solution respectively. The optimum conditions were 2% amylose, 150 W, and 20 min in the ultrasound treatment, whereas in the method by precipitation in acid solution the best conditions were 2% amylose from cassava starch with protein at 68 °C. The results obtained from DSC and FT-IR spectroscopy in the encapsulation using cryogels and xerogels indicated no formation of inclusion complexes V-type of amylose. Nevertheless, the diffraction patterns were characteristic of this type of complexes. The samples retrograded at -18 °C and dried using freeze-drying had a slightly higher encapsulation degree than the samples retrograded at 8 °C.

Le travail présenté dans ce mémoire concerne le développement d'une nouvelle technologie d'encapsulation de composants à ondes acoustiques de surface. Afin de répondre à des critères de réduction de coût et de taille, ce boîtier-puce est réalisé collectivement au niveau de la tranche et utilise des matériaux organiques bas coûts. Après avoir validé par modélisation à l'aide d'éléments finis la tenue thermo-mécanique de l'encapsulation, nous avons contrôlé théoriquement l'absence de perturbations thermomécaniques introduites par le boîtier sur la fonction centrale du filtre. .
The present work is concerned with a new surface acoustic wave device packaging. In order to reduce the size and the cost aspects, this chip size package uses low cost organic materials. It is also a wafer level technology. After studying the package thermomechanical behaviour by using a finite element method modelisation, we proved that the central frequency of the filter was not shifted by thermomechanical perturbations introduced by the package. .

Ce travail de thèse vise la définition et la mise au point de technologies pour l'empilement depuces microélectroniques dans un polymère et connectées électriquement par des viastraversants. Il explore deux voies : l’une de caractère industriel, utilisant une résine époxychargée en billes de silice E2517, l'autre, plus exploratoire, est basée sur l'utilisation de laSU8.Nous avons travaillé sur la mise au point des différentes étapes permettant d'empiler 4niveaux de puces amincies à 80 microns (enrobées) et empilées sur des épaisseurs de l'ordredu millimètre. Le problème du perçage des vias a été abordé et étudié à travers la mise aupoint de procédés d'usinage au laser des résines de type industriel. La métallisation encouches minces de ces trous de facteur de forme élevée (20) a été menée de sorte à atteindredes valeurs de résistance d'accès les plus faibles possibles.Un comparatif des deux voies utilisant la SU8 et la résine E2517 a été effectué et ses résultatscommentés en termes de faisabilité techniques et ses projections dans le domaine industriel.Des tests de fiabilité thermomécaniques ont été menés de concert avec une modélisation paréléments fini afin de valider les résultats des expérimentations réalisées dans le cadre de cetteétude
The subject of this thesis is the definition and development of TPV (Through Polymer Via)technology to stacking chips. The principal objective is to increase the potentialities of thevertical staking (complex IC; multiple I/O...) of Si chips without loss of performance or yield.The technique used consists to surround the IC chips by using particular resin and to fill (withmetallic films) the vertical holes drilled in this material. It explores two ways: one of anindustrial character, using an epoxy resin filled with silica beads E2517, other, moreexploratory, is based on the use of SU8.We worked on the development of different stages to stack four levels of chips thinned to 80microns (coated) and stacked on the thickness of one millimeter. The problem of drilling viashas been discussed and studied through the development of laser drilling processes ofindustrial resins. The thin-film metallization of the holes of high aspect ratio (20) wasconducted in order to reach values of access resistance as low as possible.A comparison of the two channels using SU8 resin and E2517 was carried out and the resultsdiscussed in terms of technical feasibility and its projections in the industrial field.Thermomechanical reliability tests were conducted in conjuction with finite element modelingto validate the results of experiments conducted in this study

Les performances des microsystèmes sont extrêmement liés à l’environnement et doivent généralement dépendre le moins possible des perturbations extérieures, comme l’humidité de l’air. C’est pourquoi ces microdispositifs sont généralement encapsulés dans un boitier hermétique qui permet à la fois de les connecter à une électronique, mais également de les protéger des variations du milieu extérieur. Mais ce type de boitiers qui représente plus de 80 % du coût du global d’un composant, est aussi à l’origine de près de 80 % des défaillances. Ainsi, il s’avère intéressant de placer directement sur le capot de silicium de l’encapsulation des capteurs environnementaux (pression, température, gaz) pour pouvoir caractériser in situ l’atmosphère interne du boitier durant la phase d’assemblage, mais également durant la phase d’utilisation. Dans ce travail, nous avons choisi d’utiliser du silicium poreux comme matériau sensible à l’humidité, qui de par sa surface spécifique élevée, permet d’augmenter la capacité d’absorption de l’humidité par rapport à un matériau massif et donc de réaliser des capteurs les plus sensibles possible, tout en restant compatible avec les spécificités induites par la technologie silicium. Pour cela, après avoir mis au point le procédé de fabrication des couches de silicium poreux par anodisation électrochimique et d’avoir caractérisé leur morphologie (porosité, surface spécifique), nous avons développé deux types de micro capteurs d’humidités susceptibles d’être intégrés à une encapsulation sur tranche constituant le boitier : des dispositifs statiques (capteurs impédimétriques) et des structures mobiles résonnantes
The performance of Micro (Opto) Electromechanical systems are highly related to the environment and have to be less dependent on external contaminants, such as humidity. There fore, these microdevises are usually encapsulated in a sealed packaging that allows to connect to electronics, but also to protect them from changes in external environment. But this type of packaging, which represents over 80 % of the overall cost of a component, is also source of nearly 80 % of failures. Thus, it is interesting to integrate environmental sensors (pressures, temperature, gas) on the silicon cap in order to characterize in situ the internal atmosphere of M(O)EMS packaging from fabrication process to the lifetime of the components. In this work, we chose to use porous silicon as humidity sensitive material, which by its high specific surface increases the absorption capacity of moisture from a solid material, therefore the sensor is highly sensitive, while remaining compatible with the specificity induced by the silicon technology. For this after the development of manufacturing process of porous silicon layers by electrochemical anodization and the characterization of their morphology (porosity, specific surface), we have developed two types of micro humidity sensors, which may be incorporated into a wafer-level (WLP) : motionless devices (impedimetric sensors) and resonant structures

Thesis (S.M.)--Harvard-MIT Division of Health Sciences and Technology, 2009.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 68-72).
'Smart' targeted drug carriers have long been sought after in the treatment of epidermal growth factor (EGF)-overexpressing cancers due to the potential advantages, relative to current clinical therapies (generally limited to surgery, radiation therapy, traditional chemotherapy, and EGF receptor inhibitors (EGFRIs)), of using such 'smart' targeted drug delivery systems. However, progress toward this goal has been challenged by the difficulty of creating a drug carrier that can autonomously detect and respond to tumor cells in the body. 'Smart' micron-size drug-encapsulating epidermal growth factor (EGF)-sensitive liposomes for EGF-overexpressing cancer therapies have been developed and studied. These drug-encapsulating liposomes remain inert until they are exposed to an abnormal concentration of EGF. As a drug delivery system, these drug-encapsulating liposomes could release pharmaceutical agents specifically in the immediate neighborhood of tumors overexpressing EGF, thereby maximizing the effective amount of drug received by the tumor while minimizing the effective systemic toxicity of the drug. Additionally, quantitative mathematical models were developed to characterize multiple critical rate processes (including drug leakage from drug-encapsulating liposomes and distribution of (drug-encapsulating) liposomes in blood vessels) associated i with (drug-encapsulating) liposomes in general.
(cont.) These quantitative mathematical models provide a low-cost and rapid method for screening novel drug-encapsulating liposome compositions, configurations, and synthetic methods to identify liposome compositions, configurations, and synthetic methods that would deliver optimal performance. The results provide a stepping stone toward the development of EGF-sensitive liposomes for clinical use. More generally, they also present implications for future development of other targeted drug delivery vehicles.
by Albert Wong.
S.M.

Radio-frequency microelectromechanical systems (RF~MEMS) are highly miniaturized devices intended to switch, modulate, filter or tune electrical signals from DC to microwave frequencies. The micromachining techniques used to fabricate these components are based on the standard clean-room manufacturing processes for high-volume integrated semiconductor circuits. RF~MEMS switches are characterized by their high isolation, low insertion loss, large bandwidth and by their unparalleled signal linearity. They are relatively simple to control, are very small and have almost zero power consumption. Despite these benefits, RF~MEMS switches are not yet seen in commercial products because of reliability issues, limits in signal power handling and questions in packaging and integration. Also, the actuation voltages are typically too high for electronics applications and require additional drive circuitry. This thesis presents a novel MEMS switch concept based on an S-shaped film actuator, which consists of a thin and flexible membrane rolling between a top and a bottom electrode. The special design makes it possible to have high RF isolation due to the large contact distance in the off-state, while maintaining low operation voltages due to the zipper-like movement of the electrostatic dual-actuator. The switch comprises two separately fabricated parts which allows simple integration even with RF circuits incompatible with certain MEMS fabrication processes. The two parts are assembled by chip or wafer bonding which results in an encapsulated, ready-to-dice package. The thesis discusses the concept of the switch and reports on the successful fabrication and evaluation of prototype devices. Furthermore, this thesis presents research results in wafer-level packaging of (RF) MEMS devices by full-wafer bonding with an adhesive intermediate layer, which is structured before bonding to create defined cavities for housing MEMS devices. This technique has the advantage of simple, robust and low temperature fabrication, and is highly tolerant to surface non-uniformities and particles in the bonding interface. It allows cavities with a height of up to many tens of micrometers to be created directly in the bonding interface. In contrast to conventional wafer-level packaging methods with individual chip-capping, the encapsulation is done using a single wafer-bonding step. The thesis investigates the process parameters for patterned adhesive wafer bonding with benzocyclobutene, describes the fabrication of glass lid packages based on this technique, and introduces a method to create through-wafer electrical interconnections in glass substrates by a two-step etch technique, involving powder-blasting and chemical etching. Also, it discusses a technique of improving the hermetic properties of adhesive bonded structures by additional passivation layers. Finally, it presents a method to substantially improve the bond strength of patterned adhesive bonding by using the solid/liquid phase combination of a patterned polymer layer with a contact-printed thin adhesive film.
QC 20100617

The thesis deals with the pouring of epoxy materials over LED strips. The research part contains an introduction to photometry and summarizes the types of potting compounds along with their characteristics. The practical part delves into the effect different amount of pigment has on the photometric properties. This is assessed based on verified measurements performed with the help of a goniophotometer on samples with different amounts of pigment, which were created using an integration sphere. Furthermore, a brightness analysis and a long-term outdoor test were performed.

Le devenir d'un agent therapeutique dans l'organisme est principalement gouverne par ses proprietes physico-chimiques. Son efficacite est souvent limitee par son incapacite a atteindre les foyers des maladies avec des taux appropries, a limiter leur action aux seuls sites vises ou a agir avec suffisamment de discernement ou encore par leur elimination trop rapide. Les bio vecteurs supra moleculaires (bvsm) sont un nouveau systeme de transport de principes actifs, constitues d'un noyau de polysaccharide reticule derive en peripherie par une couronne d'acides gras et recouvert d'un feuillet phospholipidique. La structure des bvsm peut etre adaptee en fonction de la nature physico-chimique des produits a transporter et l'objectif therapeutique souhaite. Dans une premiere partie, nous avons adapte le bvsm a l'immobilisation d'une enzyme a activite antimicrobienne: la lactoperoxydase (lp). Nous avons synthetise un bvsm de 500 nm de diametre capable de fixer la lp de maniere stable et sous une forme active, grace a l'etablissement de liaisons hydrophobes et ioniques. Cette immobilisation est etroitement liee a la nature des acides gras greffes, a la nature des phospholipides et du caractere ionique de la couronne lipidique des bvsm. Puis nous avons evalue le changement de conformation de l'enzyme, les ph et temperature optimum d'activite et la stabilite thermique qui s'est revelee significativement plus elevee. Dans une deuxieme partie, nous avons etudie le ciblage d'oligonucleotides antisens, en vue de la regulation artificielle de l'expression genetique des cellules. Nous avons synthetise un bvsm de 30 nm de diametre, avec un compartiment polysaccharidique interne derive par une amine quaternaire, capable d'incorporer un oligodesoxyribonucleotide de 17 bases et de lui procurer une protection vis-a-vis d'une attaque enzymatique

Aujourd'hui, l'encapsulation de protéines dans le but de chercher une action prolongée reste un défi dans le domaine de microencapsulation. Ce sujet de recherche attire beaucoup l'attention des chercheurs depuis des décennies en raison des avantages que l'encapsulation de protéines pourrait apporter au confort du patient et à l'efficacité du traitement thérapeutique. L'encapsulation de protéines dans des systèmes polymériques comme par exemple des microparticules de PLGA (polylactique- glycolique-acide) est une des approches permettant d'atteindre ce objectif. Nombreuses méthodes d'encapsulation ont été décrites mais le point négative généralement observé dans ces méthodes est l'utilisation des solvants organiques volatiles, considérés toxiques pour la santé humaine et l'environnement. Le but de ce travail était d'élaborer de nouveaux procédés de préparation de particules de PLGA en vue de l'encapsulation de protéine. Des solvants miscibles avec l'eau, non-volatiles et peu-toxiques (glycofurol, ,isosorbide dimethyl ether) ont été choisis pour l'utilisation dans des procédés présentés dans ce travail. Le CO2 pressurisé, possédant des propriétés physicochimiques fortement modulables, a été utilisé pour le développement de ces nouveaux procédés. Différents procédés ont été développés en basant soit sur le phénomène de séparation de phase, soit sur la méthode d'émulsification/extraction. Des particules sphériques de taille variant de 0.3 à 30 μm ont été générés avec le rendement d'encapsulation satisfaisant (65-80%). Les détails de la formulation sont présentés et le mécanisme de formation de particules est discuté. La méthodologie de plan d'expérience a été utilisée pour évaluer l'influence des paramètres opératoires et pour prédire le rendement d'encapsulation dans le domaine expérimental choisi.

Les applications radars requièrent aujourd’hui des performances très importantes en termes de puissance émise, de rendement et de bande passante, afin de réduire les coûts et l’encombrement des systèmes radars. Le transistor HEMT GaN est la technologie de puissance qui répond le plus favorablement aux applications radars en bande S. Des amplificateurs de puissance peuvent être désormais réalisés en technologie HEMT GaN de forts développements. Au cours de ces travaux de thèse, une nouvelle méthodologie d’encapsulation des barrettes de puissance GaN a été mise en œuvre afin de passer outre les techniques de conception actuelles limitant l’obtention des performances haut rendement sur de larges bandes passantes. Ainsi, une technique de synthèse de boîtier a permis d’assurer un fonctionnement optimal en rendement de la barrette de puissance GaN sur une large bande passante. Des démonstrateurs ont été réalisés et ont démontré des PAE de l’ordre 60%, associées à des puissances de sortie de 50 W sur une bande passante de 25% (autour de 3. 2 GHz) en bande S. Ces démonstrateurs proposent également une très bonne robustesse à de fortes variations de TOS aux fréquences harmoniques et présentent une surface d’adaptation sur 50 ? inférieure à 0. 7 cm²
Radar applications require more performances in terms of high efficiency, wideband and output power in order to minimize power consumption, system size and cooling. Henceforth, HEMT GaN transistor is the most suitable technology for high power requirements of radar applications in S-Band. The aim of this thesis is to propose a new methodology for power bar packaging in order to overcome usual design techniques that limit both efficiency and wideband performances. Thus, a package design was optimized to obtain an optimal behaviour of the HEMT GaN power bar and to ensure high efficiency on wide bandwidth. Optimized packaged power bars were realized demonstrating 60% PAE with 50 W output power on 25% bandwidth in S-band (around 3. 2 GHz). The robustness of these amplifiers was highlighted. They can withstand very high SWR at the harmonic frequencies without any change in performance. Moreover, dimensions of these optimized packaged power bars are lower than 0. 7 cm²

Reproduction de : Thèse de doctorat : Électronique : Lille 1 : 2005.
N° d'ordre (Lille 1) : 3631. Résumé en français et en anglais. Titre provenant de la page de titre du document numérisé. Bibliogr. à la suite de chaque chapitre. Liste des publications.

Cette thèse traite de la conception, de la fabrication et de la caractérisation d'une nouvelles architecture de microcommutateur :MEMS RF pour des applications de puissance. En effet, les composants proposés dans la littérature ne permettent pas de supporter des signaux radiofréquence de puissance. Après l'étude des limitations des solutions dites classiques, une nouvelle approche utilisant un assemblage de trois substrats micro usinés est présentée et étudiée, dont le but est de commuter des signaux hyperfréquences d'une puissance de 10W dans la bande 20MHz-2GHz. Après de nombreux compromis issus de contraintes mécaniques, thermique, hyperfréquences et thechnologique, le procédé de fabrication ainsi que les résultats obtenus sont présentés. Cette étude montre ainsi un premier démonstrateur de commutateur ohmique pour des application RF de forte puissance affiche plus de 40dB d'isolation à 2GHZ et 30dB à 20GHz pour des tensions de commande entre 30 et 60V suivant la conception mais de fortes pertes d'insertions liées au procédé technologique sont à déplorer.

Les réseaux de capteurs communiquant sans fil offrent des possibilités extrêmement intéressantes pour l'application de surveillance de santé de structures, et particulièrement dans le secteur aéronautique. Cependant les capteurs qui constituent chaque noeud du réseau ne disposent pas de ressources énergétiques permanentes et leur autonomie énergétique sur de longues périodes est un problème. Avec la réduction de la consommation des composants électroniques et des capteurs, une solution possible et explorée depuis une dizaine d'années par nombreuses équipes consiste à récupérer l'énergie disponible dans son environnement, de la stocker et la gérer pour alimenter le capteur. Nous proposons dans cette thèse d'exploiter le potentiel énergétique des vibrations mécaniques d'une structure aéronautique pour alimenter un capteur de surveillance de santé de structure aéronautique. Notre contribution porte sur la conception et l'intégration sur silicium d'un générateur piézoélectrique miniature et d'un micro dispositif de stockage capacitif. Concernant le générateur piézoélectrique, l'élaboration d'un modèle à éléments finis (COMSOL) couplées avec une description SPICE du circuit de charge, a permis de concevoir - une structure optimisée consistant en 4 poutres monomorphes (Si/PZT) capable de générer des puissance électrique > ?W et des tension > V en dépit de puissance mécaniques incidentes faibles : vibrations de 0,1g-0,5g @40-80 Hz. Ce dispositif a ensuite été réalisé sur silicium à l'aide de technologies MEMS et de l'usinage laser femtoseconde. Le dispositif de stockage conçu et intégré sur silicium est un condensateur à double couche électrochimique. Les différentes briques technologiques développées concernent l'optimisation des géométries d'électrodes, le dépôt de la matière active et l'encapsulation hermétique de l'électrolyte organique en atmosphère anhydre. Un modèle VHDL-AMS des deux éléments (récupérateur et stockage) réalisés est proposé et une simulation du systè me sur un cas d'utilisation simple est comparée à l'expérience.

L’entreprise IBM a lancé en 2014 un projet de recherche pour introduire de l’intelligence, c’est-à-dire des capteurs, dans des modules micro-électroniques. Le projet vise l’amélioration, à partir des données des capteurs, des procédés d’assemblage de puce qui serviront dans des serveurs pour du calcul haute performance ou les télécommunications.Mon projet consiste à concevoir, caractériser, puis intégrer 109 micro-capteurs, de dimensions 1 x 100 x 100 µm3, de température, humidité et contrainte sur une puce électronique de 2 x 2 cm2. L’objectif est d’obtenir en temps réel la répartition de l’humidité, la température et la contrainte dans l’assemblage, en environnement sévère.Les capteurs à base de nanotubes de carbone réalisés sont très sensibles à l’humidité et la température, avec par exemple une variation de 50% de la grandeur de sortie du capteur pour une variation de -40 à 140 °C. J’ai proposé une méthode novatrice à partir des propriétés de l’impédance du capteur permettant la séparation de la réponse à la température de celle à l’humidité
IBM is combining forces with the Université de Sherbrooke to introduce intelligency, which are sensors, in microelectronics module. The project is to make the assembly process of a chip more robust thanks to the sensor data. These microelectronics module are used in high-performance computing servers or telecommunications. The objectives are to design, characterize and embed 109 micro-sensors, having dimensions below 1 x 100 x 100 µm3. These micro-sensors will be on chip and measure temperature, moisture and strain. Thus these micro-sensors will give the spatial distribution of temperature, moisture and strain into the microelectronics module in severe environments. The carbon nanotube-based sensor realized are very sensitive to moisture and temperature, as example the output quantity value of the sensors is reduced by 50 per cent with a temperature excursions from -40 to 140 ℃. I developed a novel method to separate the temperature response from the moisture one, using the impedance properties of the sensor

L’ingénierie protéique servant autrefois à comprendre les relations structures-fonctions des protéines connait un tournant majeur depuis plusieurs années. L’ingénierie protéique évolue pour créer des nouvelles fonctions protéiques : c’est la naissance de l’ingénierie protéique moderne. L’objectif de ma thèse a consisté à mettre en place et caractériser deux approches indépendantes d’ingénierie protéique dans le domaine du vaccin et du diagnostic. Le premier projet consistait à générer des ligands protéiques à partir d‘échafaudages moléculaires (des alternatifs aux anticorps) en couplant le ribosome display au NGS et en développant des outils d’analyses bio-informatiques. Des sélections contre des cibles protéiques d’origine bactérienne et virale ont conduit à l’identification de ligands Affibodies affins (µM au nM). Leur caractérisation a validé leur potentiel comme outil de recherche et de réactif diagnostique. Ces études ont permis de valider la plateforme de génération des ligands mise en place, en augmentant l’exploration de l’espace de diversité des interactions des ligands. Le second projet portait sur le développement d’une plateforme de présentation et de vectorisation à partir de particules d’encapsuline. Elles ont été génétiquement modifiées pour présenter de manière répétée à leur surface l’ectodomaine de la protéine de matrice M2 (M2e) du virus Influenza A H1N1 tout en encapsulant une protéine hétérologue : l’eGFP. Les nanoparticules modifiées sont correctement formées et encapsulent l’eGFP. Des souris immunisées par ces particules induisent une réponse anticorps spécifique contre l’épitope M2e et l’eGFP. L’utilisation de ces nanoparticules comme plateforme vaccinale de présentation et de vectorisation est prometteuse et ouvre la voie pour d’autres applications en biotechnologie
In the past, protein engineering used to understand function and structure relationship. But since few years, protein engineering was used to create new protein functions: modern protein engineering was born. The aim of my thesis was to set up and characterize two approaches of protein engineering in diagnostic and vaccine field. The first project was to generate artificial binder using protein scaffolds as an alternative to antibodies by coupling ribosome display (RD) to NGS and developing bio-informatics tools. Screening and selection against bacterial and viral targets have led to affibody binder’s identification with an affinity range from µM to nM. Their characterization has validated their potential as research tools and protein reagents for diagnostic assay. Coupling ribosome display to high throughput sequencing as means to directly identify selected binder coding sequences, enormously enhance binder discovery depth. The second project was to generate an innovative nanocarrier based on encapsulin nanoparticle, for customized peptide display and cargo protein vectorization. Encapsulin particles from T.maritima were genetically modified for simultaneous display of the matrix protein 2 ectodomain of the influenza H1N1 A virus and heterologous protein eGFP packaging. Genetically engineered encapsulin nanoparticles were well-formed and abled to efficiently load eGFP. Immunogenicity studies revealed antibody responses against both the surface epitope and the loaded cargo protein. Taken together, this display system is a versatile tool for rational vaccine design and paves the way for new applications in the research fields of vaccine, antimicrobial research and other biotechnological applications

Les capsules, composées d'une goutte entourée d'une fine membrane élastique, ont un fort potentiel d'applications pour contrôler le relargage d'une substance. Une limitation est qu'on ne dispose pas de modèle de la rupture des capsules en écoulement. Pendant la thèse, un modèle numérique d’interaction fluide-structure a été développé pour une capsule sous écoulement de Stokes, en tenant compte de I’endommagement de la membrane jusqu’à l'initiation d'une fissure. Il couple la méthode des intégrales de frontière, pour résoudre les écoulements des fluides, et la méthode des éléments finis, pour calculer la déformation de la membrane. Le cadre de la mécanique de l'endommagement continu a été retenu pour modéliser la membrane. L'endommagement a été étudié pour une capsule sphérique dans un écoulement de cisaillement simple avec un modèle d'endommagement quasi-fragile de la membrane. L’influence de la force de l’écoulement et les conditions d'initiation de la rupture ont été étudiées, et les paramètres du modèle identifiés à partir de résultats expérimentaux. Un second modèle d'endommagement a été proposé pour décrire un autre mode de rupture observé expérimentalement dans cet écoulement. Dans une dernière partie, on a étendu le modèle afin de mieux décrire la phase ultime d'endommagement précédant l'apparition d'une fissure, lorsque l’endommagement se concentre dans des bandes de faible épaisseur (zones de localisation). On s'est placé pour cela dans le cadre de l'approche des discontinuités fortes, et on a considéré les zones de localisation comme des interfaces cohésives. Ces travaux sont une première étape décisive pour modéliser la rupture des capsules en écoulement
Capsules, composed of a droplet surrounded by a thin elastic membrane, have a high potential of applications to control the release of a substance. One limitation is the absence of models of the rupture of capsules in flow. During the thesis, a fluid-structure interaction numerical model was developed for a capsule under Stokes flow, taking into account the damage of the membrane until the initiation of a crack. It couples the boundary integral method, to solve for the fluid flows, and the finite element method, to solve for the membrane deformation. The framework of continuum damage mechanics was chosen to model the membrane. Damage was studied for a spherical capsule in a simple shear flow with a quasi-brittle damage model of the membrane. The influence of the force of the flow and the conditions of initiation of rupture were studied, and the parameters of the model identified from experimental results. A second damage model was proposed to describe another mode of rupture observed experimentally in this flow. In the last section, the model was extended to have a better description of the ultimate phase of damage preceding the emergence of a crack, when damage concentrates in bands of small thickness (localization zones). We placed ourselves in the framework of the strong discontinuity approach, and we considered the localization zones as cohesive interfaces. This work is a decisive first step to model the rupture of capsules in flow

The increasing prevalence of diabetes and the severity of long-term complications have emphasized the need for continuous glucose monitoring. Optically-based methods are advantageous as they have potential for noninvasive or minimally invasive detection. Fluorescence-based affinity assays, in particular, can be fast, reagentless, and highly specific. Poly(ethylene glycol) (PEG) microspheres have been used to encapsulate such fluorescently labeled molecules in a hydrogel matrix for implantation into the body. The matrix is designed to retain the sensing molecules while simultaneously allowing sufficient analyte diffusion. Sensing assays which depend upon a spatial displacement of molecules, however, experience limited motility and diminished sensor response in a dense matrix. In order to overcome this, a process of hydrogel microporation has been developed to create cavities within the PEG that contain the assay components in solution, providing improved motility for large sensing elements, while limiting leaching and increasing sensor lifetime. For an implanted sensor to be successful in vivo, it should exhibit long-term stability and functionality. Even biocompatible materials that have no toxic effect on surrounding tissues elicit a host response. Over time, a fibrous capsule forms around the implant, slowing diffusion of the target analyte to the sensor and limiting optical signal propagation. To prevent this biofouling, a thermoresponsive nanocomposite hydrogel based on poly(N-isopropylacrylamide) was developed to create a self-cleaning sensor membrane. These hydrogels exist in a swollen state at temperatures below the volume phase transition temperature (VPTT) and become increasingly hydrophobic as the temperature is raised. Upon thermal cycling around the VPTT, these hydrogels exhibit significant cell release in vitro. However, the VPTT of the original formula was around 33-34 degrees C, resulting in a gel that is in a collapsed state, ultimately limiting glucose diffusion at body temperature. The hydrogel was modified by introducing a hydrophilic comonomer, N-vinylpyrrolidone (NVP), to raise the VPTT above body temperature. The new formulation was optimized with regard to diffusion, mechanical strength, and cell releasing capabilities under physiological conditions. Overall, this system is a promising method to translate a glucose-sensitive assay from the cuvette to the clinic for minimally invasive continuous glucose sensing.

碩士
國立虎尾科技大學
光電與材料科技研究所
101
In this study, the measurement of the calcium test (resistive), calcium for water reaction produces a change in resistance, the measured resistance value and then converted WVTR (Water Vapor Transmission Rate), using three different encapsulations of: general commercial PET (polyethylene terephthalate), atomic layer deposited film of PET/Al2O3/HfO2, sand-blasted glass, translation of WVTR, respectively, as follows: PET: 3 g/m2/day、PET/Al2O3/HfO2: 0.23 g/m2/day, and using an optical Optical Microscope the changes in calcium over time. Green phosphorescent organic light-emitting diodes, the phosphorescent light-emitting material (RH02) and green phosphorescent guest emitter doped materials (GD01) single-layer light-emitting element, the structure of ITO/HI02/RH02: GD01/ET02/LiF/Al the light emitting efficiency of 18 cd / A, the color coordinates (0.33,0.6). We green phosphorescent structure, were three packages: general commercial PET (polyethylene terephthalate), atomic layer deposition film (ALD Atomic Layer Deposition) film PET / ALD, glass sandblasting, as the cover package, and life measurement, dark spots element contacts the environmental impact of the water vapor changes over time, observed using an optical microscope components. In this study, the first dry-etching the ITO glass, a test piece were measured with three points, using the non-deposited PET for packaging, the ambient temperature 27.54 ℃ 45% relative humidity measurements, the measured slope conductance were : -32.26/day, -29.68/day, -25.84/day, converted into water vapor transmission rate formula is: 2.64 g/m2/day, 2.43 g/m2/day, 4.04 g/m2/day, plus total After an average of 3 g/m2/day, and PET measurements carried out MOCON water vapor transmittance value of 3.2 g/m2/day difference of 0.2 g/m2/day; using ALD (Atomic Layer Deposition) water-blocking film deposition The PET/Al2O3/HfO2 encapsulation, measuring the three points slope conductance were: -4.13/day, -2.4/day, -2.1/day, converted into water vapor transmission rate formula is: 0.33 g/m2/day, 0.19 g/m2/day, 0.17 g/m2/day, add up an average of 0.23 g/m2/day, with PET/Al2O3/HfO2 carried out MOCON measurement of water vapor transmittance value of 0.24 g/m2/day difference of 0.01 g/m2/day. Making green phosphorescent organic light-emitting diodes, using three ETL materials (ET02, ET04, ET07) were compared to the thickness of 30 nm production components, found ET04, ET07 when the ETL material components have a green and orange-red band emission color is yellow, but the PL (Photoluminescence) to measure the main emitting layer material has not issued orange band light characteristics, adjusting electron-hole complex area, both the composite area in the main emitting layer composite region; to add components to a layer of high HOMO The hole injection layer block hole, though only drop the drive voltage 0.15 V, improved brightness 1300 cd/m2, in order to reduce the driving voltage electron injection to enhance the ability to use Liq co-evaporation with ET02, significantly ahead of the driving voltage 2.9 V , at 9 V when the current density has 85 mA/cm2, then take advantage of this green phosphorescent device structure is encapsulated measuring life. Use of non-deposited PET packaging, initial luminance of 300 cd/m2 ambient temperature 27.54 ℃ relative humidity 45%, measured half-life time of 14 hours was observed using an optical microscope, the light emitting area of 90% in decline there are many dark spots formation, when up to half-time, because water vapor and oxygen penetration caused by organic thin film deteriorates when the voltage 4 V points off the elements required to have a greater voltage to drive the voltage 5 V, finding not only the formation of many dark spots, but also There are many bubble-like dark spots around the vicinity of the element gradually decline; using PET/ALD encapsulation, initial brightness of 300 cd/m2, the half-life time of 66 hours, more than a layer of water-blocking film PET, life expectancy has improved significantly many ; with glass cover (no hygroscopic agent) package, starting Brightness 300 cd/m2, when the index was 88% of the attenuation measured 800 hours, estimated up to half the measurement time is approximately 3400 hours, in addition to the start Brightness 1000 cd/m2, when 90% of the attenuation index measurement time is 95 hours, estimates of half-life measurement time is about 540 hours, compared to the initial luminance difference of 3.33 times, 6.29 times the half-life of a difference more.

博士
靜宜大學
食品營養學系
103
The behaviours of lactic acid bacteria cultured in soy milk and green tea extract and then spray dried into microcapsules were investigated. In addition , the production and properties of biosurfactant from Alcaligenes piechaudii CC -ESB2 were also investigated. The minimum populations of five tested strains cultured in soy milk including B. adolescentis, B.infantis, L. acidophilus, L. brevis and L. fermentum were found to be higher than 6.0 log CFU/mL , which is the standard population of health benefits. Generally, lactic acid bacteria spray dried microcapsules produced with spray drying inlet temperature / outlet temperature at 120/60 ℃ had ideal performances in survival, water activity and moisture content . The size of the microcapsules (particle size) was affected by carrier, but not by bacteria (core material). The moisture sorption isotherm ,too, was affected by carrier, but not by bacteria (core material). Particle size of microcapsule should be large enough for the bacteria to live. The level of IMOS(isomaltooligosaccharide syrup) in carriers increased, the survival of lactic acid bacteria decreased. Microencapsulated lactic acid bacteria was found more resistant than free one to low pH test and was also found that lactic acid bacteria could proliferate with IMOS under bile salts condition.The permeability of cell membrane increased owing to high spray drying temperature and high level of IMOS in carrier and would cause the damage of cells. The viable B. adolescentis and L. acidophilus cultured in green tea extract were lower than cultured in MRS broth, but they survived to the high spray drying temperature better than the later. B. adolescentis spray drying process by not only its secretion and antibacterial effects are still better than some of those without spray drying antibacterial effect. The microcapsule added with the biosur-factant from Alcaligenes piechaudii CC-ESB2 would increase the flow ability than those who did not add. Eight BECMHFs (biosurfactant extracts from Chinese medicinal herb fermentation) produced using Alcaligenes piechaudii CC-ESB2 exhibited antioxidant capabilities, including ,2-diphenyl-1-picrylhydrazyl (DPPH) radical and superoxide scavenging activity, and superoxide dismutase (SOD)-like activity at a concentration of 10 mg/ml.

碩士
國立虎尾科技大學
光電與材料科技研究所
101
In this study, first produced yellow fluorescent organic light-emitting diodes, the main use of fluorescent phosphor material (Ni-701), and yellow dopant material (Ni-904) produced a single light-emitting layer element structure ITO/Ni-100 / HTG-1/Ni701: Ni-904/Alq3, at 50 mA/cm2, the best of the operating voltage of 7.55 V, components of the current efficiency of 14.85 cd /A, luminance of 7150 cd/m2, CIE color coordinates of (0.46, 0.52), and then use this structure to join the blue yellow and blue light-emitting layer doped host materials two-band white fluorescent device, its structure is ITO/Ni-100/HTG-1/UBH-15: EB-502 / Ni701: Ni-904/Alq3, at 50 mA/cm2, the best of the operating voltage of 7.3 V, a current efficiency of element 8.9 cd / A, luminance of 5000 cd/m2, CIE color coordinates of (0.19, 0.31). The electron transport layer was added n-type doped material Liq efficiency and brightness can be increased to 10.0 cd / A, 5250 cd/m2, the yellow dopant material (Ni-904) in a light-emitting wavelength 560 nm, and the sky blue dopant material (EB-502) to produce white light with a color rendering component is low, thus replacing the yellow orange doped material doped material (EY-53) luminescence band at 580 nm, produced two bands white fluorescent element structure ITO/Ni-100 / HTG-1/UBH-15: EB-502 / Ni701: EY-53/Alq3, optimized full-screen white OLED at optimized operating voltage 7.5 V, a current efficiency of element 9.2 cd /A, luminance of 4500 cd/m2, CIE color coordinates of (0.33, 0.35), and the applied voltage from 5V to 10V, the color coordinates shift element only (0.006, 0.0076). Use of the dispenser on a glass substrate coated with a liquid required for the measurement hygroscopic agent, by heating the liquid moisture curing agent, the environment will begin to absorb water vapor, were compared under the nitrogen atmosphere bake the weight of water hygroscopic agent can bake 50 minutes under N2 atmosphere hygroscopic agent placed in the atmosphere 180 minutes to reach 32.18% water absorption than baking under atmospheric conditions also produce more of 27.72% 4.46%, and finally the moisture absorbent transmittance measurements, the 420 nm-660 nm wavelength of visible light transmittance of 80% or more of all completed test after moisture absorption agent, hygroscopic agent into the liquid packaging process.

碩士
國立虎尾科技大學
光電與材料科技研究所
98
In this study use phosphor-sensitizer can be used as high efficiency light-emitting materials, because it has high efficiency and high energy gap effect, and the phosphorscent as a sensitizer has advantages of using energy transfer, transfer to a lower energy gap of the fluorescence. This thesis is based on the high-efficiency green phosphorescent guest emitter (Ir(ppy)3) and fluorescent red dopants (DCJTB) and yellow fluorescent dopants (EY53) were doped in a high-energy level (CBP) in the production of the main light yellow light-emitting layer. In order to improve the life of components, and then days with high-efficiency blue fluorescent dopants (BUBD-1) doped bipolar light-emitting fluorescent main body (MADN) and the broadband spectrum of white light. The device at 20mA/cm2 current efficiency of 21cd/A, the E.Q.E. of 6.62%, and CIE of (0.40,0.46) for white light. In addition to p-type doped material (WO3) and n-type dopants (Cs2CO3) were doped hole transport layer (NPB) and electron transport layer (BPhen) as the p-hole transport layer and the n-type electronic transmission layer to significantly reduce device voltage to achieve high efficiency and high brightness of the white organic light-emitting diodes. Also for flexible substrates, to produce new packaging technology, in PDMS thin films deposited on silicon dioxide (to increase resistance to water penetration of oxygen. This method produced without the use of solvent protective coating to achieve the goal of low cost and simplicity.