Development of SiC-LC Resonant Wireless High Temperature Pressure Sensor

高温压力传感器在航天、航空、国防建设、能源开发等领域有广阔应用需求。传统硅材料在高于200℃后机械/电学性能均受到较大影响，无法满足高温应用要求。另一方面，传统高温传感器引线会导致电源、信号电路的温度升高问题，基于LC谐振的无线传感器能实现非接触式测量，达到电性连接、调理电路与高温热源之间物理隔离，提高传感器工作温度和稳定工作时间。因此，本论文提出一种SiC-LC谐振式无线高温压力传感器，主要研究工作如下： (1)根据LC谐振测量原理设计电感内置及电感外置两种敏感元件的结构方案，采用Silvaco软件对本体电容进行对比分析，得出电感内置结构具有本体电容小、谐振信号易于检测、制备工艺难度更低等...High temperature pressure sensor has broad application requirements in aerospace, aviation, national defense construction, energy development and other fields. Silicon material performance is greatly affected in the higher than 200℃ performance, can not meet the requirements of high temperature applications. At present, high temperature sensor will lead to power supply, signal circuit temperature...学位：工学硕士院系专业：航空航天学院_电气检测技术及仪器学号：1992014115289

HIGH PERFORMANCE PIEZOELECTRIC MATERIALS AND DEVICES FOR MULTILAYER LOW TEMPERATURE CO-FIRED CERAMIC BASED MICROFLUIDIC SYSTEMS

The incorporation of active piezoelectric elements and fluidic components into micro-electromechanical systems (MEMS) is of great interest for the development of sensors, actuators, and integrated systems used in microfluidics. Low temperature cofired ceramics (LTCC), widely used as electronic packaging materials, offer the possibility of manufacturing highly integrated microfluidic systems with complex 3-D features and various co-firable functional materials in a multilayer module. It would be desirable to integrate high performance lead zirconate titanate (PZT) based ceramics into LTCC-based MEMS using modern thick film and 3-D packaging technologies. The challenges for fabricating functional LTCC/PZT devices are: 1) formulating piezoelectric compositions which have similar sintering conditions to LTCC materials; 2) reducing elemental inter-diffusion between the LTCC package and PZT materials in co-firing process; and 3) developing active piezoelectric layers with desirable electric properties. The goal of present work was to develop low temperature fired PZT-based materials and compatible processing methods which enable integration of piezoelectric elements with LTCC materials and production of high performance integrated multilayer devices for microfluidics. First, the low temperature sintering behavior of piezoelectric ceramics in the solid solution of Pb(Zr0.53,Ti0.47)O3-Sr(K0.25, Nb0.75)O3 (PZT-SKN) with sintering aids has been investigated. 1 wt% LiBiO2 + 1 wt% CuO fluxed PZT-SKN ceramics sintered at 900oC for 1 h exhibited desirable piezoelectric and dielectric properties with a reduction of sintering temperature by 350oC. Next, the fluxed PZT-SKN tapes were successfully laminated and co-fired with LTCC materials to build the hybrid multilayer structures. HL2000/PZT-SKN multilayer ceramics co-fired at 900oC for 0.5 h exhibited the optimal properties with high field d33 piezoelectric coefficient of 356 pm/V. A potential application of the developed LTCC/PZT-SKN multilayer ceramics as a microbalance was demonstrated. The final research focus was the fabrication of an HL2000/PZT-SKN multilayer piezoelectric micropump and the characterization of pumping performance. The measured maximum flow rate and backpressure were 450 μl/min and 1.4 kPa respectively. Use of different microchannel geometries has been studied to improve the pumping performance. It is believed that the high performance multilayer piezoelectric devices implemented in this work will enable the development of highly integrated LTCC-based microfluidic systems for many future applications

Diode laser modules based on laser-machined, multi-layer ceramic substrates with integrated water cooling and micro-optics

This thesis presents a study on the use of low temperature co-fired ceramic (LTCC) material as a new platform for the packaging of multiple broad area single emitter diode lasers. This will address the recent trend in the laser industry of combining multiple laser diodes in a common package to reach the beam brightness and power required for pumping fibre lasers and for direct-diode industrial applications, such as welding, cutting, and etching. Packages based on multiple single emitters offer advantages over those derived from monolithic diode bars such as higher brightness, negligible thermal crosstalk between neighbouring emitters and protection against cascading failed emitters. In addition, insulated sub-mounted laser diodes based on telecommunication standards are preferred to diode bars and stacks because of the degree of assembly automation, and improved lifetime. At present, lasers are packaged on Cu or CuW platforms, whose high thermal conductivities allow an efficient passive cooling. However, as the number of emitters per package increases and improvements in the laser technology enable higher output power, the passive cooling will become insufficient. To overcome this problem, a LTCC platform capable of actively removing the heat generated by the lasers through impingement jet cooling was developed. It was provided with an internal water manifold capable to impinge water at 0.15 lmin-1 flow rate on the back surface of each laser with a variation of less than 2 °C in the temperature between the diodes. The thermal impedance of 2.7°C/W obtained allows the LTCC structure to cool the latest commercial broad area single emitter diode lasers which deliver up to 13 W of optical power. Commonly, the emitters are placed in a “staircase” formation to stack the emitters in the fast-axis, maintaining the brightness of the diode lasers. However, due to technical difficulties of machining the LTCC structure with a staircase-shaped face, a novel out-plane beam shaping method was proposed to obtain an elegant and compact free space combination of the laser beam on board using inexpensive optics. A compact arrangement was obtained using aligned folding mirrors, which stacked the beams on top of each other in the fast direction with the minimum dead space

3D Structuration Techniques of LTCC for Microsystems Applications

This thesis aimed at developing new 3D structuration techniques for a relatively recent new ceramic technology called LTCC, which stands for Low Temperature, Co-fired Ceramic. It is a material originally developed for the microelectronic packaging industry; its chemical and thermal stabilities make it suitable to military-grade and automotive applications, such as car ignition systems and Wi-Fi antennae (GHz frequencies). In recent years however, the research in ceramic microsystems has seen a growing interest for microfluidics, packaging, MEMS and sensors. Positioned at the crossing of classical thick-film technology on alumina substrate and of high temperature ceramics, this new kind of easily structurable ceramic is filling the technological and dimensional gap between microsystems in Silicon and classical "macro microsystems", in the sense that we can now structure microdevices in the range from 150 mm to 150 mm. In effect, LTCC technology allows printing conductors and other inks from 30 mm to many mm, structuration from 150 mm to 150 mm, and suspended structures with gaps down to 30 mm thanks to sacrificial materials. Sensors and their packaging are now merged in what we can call "functional packaging". The contributions of this thesis lie both in the technological aspects we brought, and in the innovative microfluidic sensors and devices created using our developed methods. These realizations would not have been possible with the standard lamination and firing techniques used so far. Hence, we allow circumventing the problems related to microfluidics circuitry: for instance, the difficulty to control final fired dimensions, the burden to produce cavities or open structures and the associated delaminations of tapes, and the absence of "recipe" for the industrialization of fluidic devices. The achievements of the presented research can be summarized as follows: The control of final dimensions is mastered after having studied the influence of lamination parameters, proving they have a considerable impact. It is now possible to have a set of design rules for a given material, deviating from suppliers' recommendations for the manufacture of slender structures requiring reduced lamination. A new lamination method was set up, permitting the assembly of complex microfluidic circuits that would normally not sustain standard lamination. The method is based on partial pseudo-isostatic sub-laminations, with the help of a constrained rubber, subsequently consolidated together with a final standard uniaxial lamination. The conflict between well bonded tapes and acceptable output geometry is greatly attenuated. We achieved the formulation of a new class of Sacrificial Volume Materials (SVM) to allow the fabrication of open structures on LTCC and on standard alumina substrates; these are indeed screen-printable inks made by mixing together mineral compounds, a glassy phase and experimental organic binders. This is an appreciable improvement over the so-far existing SVMs for LTCC, limited to closed structures such as thin membranes. An innovative industrial-grade potentially low-cost diagnostics multisensor for the pneumatic industry was developed, allowing the measurement of compressed air pressure, flow and temperature. The device is entirely mounted by soldering onto an electro-fluidic platform, de facto making it a true electro-fluidic SMD component in itself. It comprises additionally its own integrated SMD electronics, and thanks to standard hybrid assembly techniques, gets rid of external wires and tubings – this prowess was never achieved before. This opens the way for in situ diagnostics of industrial systems through the use of low-cost integrated sensors that directly output conditioned signals. In addition to the abovementioned developments, we propose an extensive review of existing Sacrificial Volume Materials, and we present numerous applications of LTCC to sensors and microsystems, such as capacitive microforce sensors, a chemical microreactor and microthrusters. In conclusion, LTCC is a technology adapted to the industrial production of microfluidic sensors and devices: the fabrication steps are all industrializable, with an easy transition from prototyping to mass production. Nonetheless, the structuration of channels, cavities and membranes obey complex rules; it is for the moment not yet possible to choose with accuracy the right manufacturing parameters without testing. Consequently, thorough engineering and mastering of the know-how of the whole manufacturing process is still necessary to produce efficient LTCC electro-fluidic circuits, in contrast with older techniques such as classical thick-film technology on alumina substrates or PCBs in FR-4. Notwithstanding its lack of maturity, the still young LTCC technology is promising in both the microelectronics and microfluidics domains. Engineers have a better understanding of the structuration possibilities, of the implications of lamination, and of the most common problems; they have now all the tools in hand to create complex microfluidics circuits

Multifunctional Advanced Ceramics for Aeronautical and Aerospace Applications: Study of MgO Al2O3, MgO CaZrO3, and YSZ Ceramic Composites

The premise that materials permeate all aspects of our day-a-day lives is well established. The relentless pursuit for increased performance in aeronautical and aerospace industries over the last decades has provided a solid driving force for the study, research, and investigation of advanced ceramics for numerous future investments. The advanced ceramics field is believed to be an enabling technology with the potential to deliver high-value contributions for meeting both future needs and challenges. Moreover, the advanced ceramics industry is quite distinctive due to its high diversity and interdisciplinary nature that encompasses an engaging number of different processing methodologies and a variety of applications. In this sense, this dissertation project focused to perform an extensive and comprehensive literature review research, in addition to further selection, fabrication, testing, and analysis of MgO Al2O3 , MgO CaZrO3 , and YSZ ceramic materials which are intended to satisfy the condition of advanced multifunctional ceramic in the aeronautical and aerospace fields. Within this framework of thought, thermal protection systems, thermal barrier coatings, and dielectric barrier discharge plasma actuator applications were perceived and adopted as a jumping-off point. A step–by–step approach was adopted for the experimental procedure. More precisely, initially, ceramic compositeMgO Al2O3 , MgO CaZrO3 , and YSZ samples were manufactured through a four stages process, i.e., material preparation, processing, sintering, and finishing. After the rectangular plates, bars, and disc specimens were obtained for the three referred compositions, the in-depth study under the microstructural, physical, mechanical, thermal, and electrical characterization followed. Ultimately, many fine ceramics are multifunctional and therefore predestined to solve the forthcoming technological and engineering challenges. It is believed that ceramics offer an enormous potential to be exploited with the knowledge of material science, i.e., through correlations between microstructural, physical, mechanical, thermal, and electrical features.A premissa de que os materiais são elementos essenciais e que moldam todos os aspetos do nosso dia-a-dia é bem reconhecida. A procura incansável das últimas décadas pelo aumento de desempenho nas indústrias de aeronáutica e aeroespacial forneceu uma força motriz sólida para o estudo, pesquisa e investigação das cerâmicas avançadas para inúmeras aplicações futuras. Acredita-se que o campo das cerâmicas avançadas seja uma tecnologia estimulante com potencial para fornecer contribuições de alto valor por forma a assegurar as necessidades e desafios futuros. Além disso, a indústria da cerâmica avançada é preconizada como sendo uma indústria significativamente distinta devido à sua diversidade característica e natureza interdisciplinar. Como consequência, um número elevado de diferentes metodologias de processamento, assim como uma ampla variedade de aplicações são parte integrante deste sector. Desta forma, esta dissertação teve como objetivo a realização de uma extensa e abrangente pesquisa de revisão de literatura, juntamente com a seleção, fabricação, teste e análise dos compósitos cerâmicos MgO Al2O3 , MgO CaZrO3 e YSZ que por sua vez se destinam a satisfazer a condição de cerâmica multifuncional nas áreas aeronáutica e aeroespacial. Para a concretização deste objetivo, sistemas de proteção térmica, revestimentos de barreira térmica e aplicações de atuadores a plasma de descarga de barreira dielétrica foram considerados e adotados como um ponto de partida. Uma abordagem sequencial foi empregue para a execução do procedimento experimental. Mais precisamente, inicialmente, as amostras de compósitos cerâmicos MgO Al2O3 , MgO CaZrO3 e YSZ foram fabricadas através de um processo subdividido em quatro etapas, isto é, preparação do material, processamento, sinterização e acabamento. Após a obtenção das diversas amostras, isto é, placas retangulares, barras e discos cerâmicos, para as três composições referidas, prosseguiu-se com o estudo das mesmas através da caracterização e análise das propriedades microestruturais, físicas, mecânicas, térmicas e elétricas. Em suma, conclui-se que muitas cerâmicas avançadas são na sua essência multifuncionais e, portanto, predestinadas a promover a resolução dos futuros desafios quer tecnológicos, assim como de engenharia. Por último, com o desenvolvimento desta dissertação, defende-se que as cerâmicas avançadas oferecem um proeminente potencial ainda por ser explorado com o auxílio do conhecimento da ciência dos materiais, ou seja, por meio de correlações entre características microestruturais, físicas, mecânicas, térmicas e elétricas

NASA patent abstracts bibliography: A continuing bibliography. Section 1: Abstracts (supplement 40)

Abstracts are provided for 181 patents and patent applications entered into the NASA scientific and technical information system during the period July 1991 through December 1991. Each entry consists of a citation, an abstract, and in most cases, a key illustration selected from the patent or patent application

NASA patent abstracts bibliography: A continuing bibliography. Section 1: Abstracts (supplement 39)

Abstracts are provided for 154 patents and patent applications entered into the NASA scientific and technical information systems during the period Jan. 1991 through Jun. 1991. Each entry consists of a citation, an abstract, and in most cases, a key illustration selected from the patent or patent application

Nanofibers - production, properties and functional applications

With the rapid development of nanoscience and nanotechnology over the last decades, great progress has been made not only in the preparation and characterization of nanomaterials, but also in their functional applications. As an important one-dimensional nanomaterial, nanofibers have extremely high specific surface area because of their small diameters, and nanofiber membranes are highly porous with excellent pore interconnectivity. These unique characteristics plus the functionalities from the materials themselves impart nanofibers with a number of novel properties for applications in areas as various as biomedical engineering, wound healing, drug delivery and release control, catalyst and enzyme carriers, filtration, environment protection, composite reinforcement, sensors, optics, energy harvest and storage , and many others. More and more emphasis has recently been placed on large-scale nanofiber production, the key technology to the wide usages of nanofibers in practice. Tremendous efforts have been made on producing nanofibers from special materials. Concerns have been raised to the safety issue of nanofibrous materials. This book is a compilation of contributions made by experts who specialize in their chosen field. It is grouped into three sections composed of twenty-one chapters, providing an up-to-date coverage of nanofiber preparation, properties and functional applications. I am deeply appreciative of all the authors and have no doubt that their contribution will be a useful resource of anyone associated with the discipline of nanofibers

Index to 1986 NASA Tech Briefs, volume 11, numbers 1-4

Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1986 Tech Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences