49 research outputs found

    Ancient and historical systems

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    Multi-material additive manufacturing of electronics components: A bibliometric analysis

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    The study presents a bibliometric analysis of studies conducted on multi-materials printing of electronic com-ponents via additive manufacturing technologies. Using the R package and the associated biblioshiny, the study analyzed publications from Web of Science and Scopus. The study analyzed 405 research articles after removing 104 duplicates. The study applied performance analysis, keyword analysis, and network analysis. The perfor-mance analysis showed that the publications on multi-materials additive manufacturing are multi-disciplinary. Whilst the publications span almost three decades, most contributions started after 2015. The United States of America is the country with the highest production. The keyword analysis showed a changed focus before and after 2015. The trending topics show that the most recent trend is in the 'aerospace industry'. Finally, the thematic analysis shows that the emerging themes in the area are interfaces, moisture, diffusion, microstructure, mechanical properties, and powder metallurgy. These emerging themes are discussed as they are conceived as the future directions of multi-materials printing of electronic components and devices. The current trend of research focuses on understanding and improving the interfacial bonding between the various multi-material interfaces. Overcoming the weak interfacial bonding issues would improve the mechanical properties of multi-materials electronic components

    Industrialization: Quantitative framework, technological dimension and the future we cannot ignore

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    The paper presents some results of the research that has been systematically conducted over a long period at the Academy of Engineering Sciences of Serbia (AINS) in the area of modern industrial and especially manufacturing technologies, as well as interactions among engineering sciences, technology and the society. The issue of industrialization is closely connected with this research and it is in this context that fresh insights are offered into industrial development, ones that are essentially different from the prevailing stereotypes that have for years been dominant in the management of the economic system in Serbia. Following the introductory chapter that gives a short review of the genesis of Serbian industry, the author offers a view of the industrial system through three chapters: 1) Industrial system of Serbia - Quantification, problems and implications; 2) Restoration and recovery framework - Industrial policies and strategic framework for fast and sustainable exiting the crisis condition; and 3) New industry of Serbia - Serbian industry transformation in the context of European integration processes, the future context (factories of the future), challenges and needs, where special attention is paid to the analysis of the problem of science pragmatization and its active part in the process of industrialization in the framework of the vertical and horizontal technology transfer, as part of the European integrations of Serbia

    Mechanical characterisation of micro-stereolithographic materials

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    Promising techniques such as micro-stereolithography (MSL) are opening up practical potential for exploiting new ideas for specialized polymer-based Micro-Electromechanical systems (MEMS) through small-batch production. As the field matures and grows, substantial research and commercial development demands better understanding of mechanical properties of MEMS materials to fully explore the potential of this technology. Bulk properties derived from conventional testing of large specimens (at 10 mm order) cannot be trusted. However, small-scale specimens (less than 1 mm) introduce major challenges, such as handling and mounting. The aim of this study was to contribute towards an improved understanding of the mechanical properties of the polymers (MSL materials) with a strong emphasis on developing new metrology. It proposed and described a special form of test-rig and compatible special MSL specimen design. A uniaxial tensile approach was chosen, partly because it offered simpler uncertainty models. The prototype used deadweight loading through a notch flexure, which acted both as a spring in parallel sharing the same displacement with the specimen and as a linear guideway. The specimen was integrally fabricated with large clamping regions and support bars released by cutting. Stiffly constrained mounting and loading surfaces were used to clamp MSL specimens to the flexure, protecting them against parasitic motions during the test in combination. Strain was measured through an elongation measurement by high-sensitivity capacitive micrometry, knowing the specimen dimensions. Verification tests on the clamping conditions showed no significant evidence of sudden slip or creep. MSL specimens were fabricated by a projection-based Envisiontec Perfactory system using a commercial acrylate-based R11 resin. Substantial shrinkage and curl distortion had been observed, which greatly reduced the fabrication accuracy of the MSL specimens. Specimens with different UV exposures and different sizes were fabricated and tested for better understanding of the MSL fabrication process. Typically, Young’s Modulus was a little smaller than expected and certainly dependent on both size and process parameters (in the region studied)

    Offshoring of R&D activities by Multinational Corporations

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    This thesis attempts to extend the current understanding of the R&D offshoring process with specific focus on determinants of location choice for R&D activities. The literature dealing with the determinants of location choice is largely fragmented and hence this thesis attempts to integrate the different prevailing perspectives. Based on transactional cost economics, resource-based view and eclectic paradigm, this thesis adopts a multi-level approach to examine country, firm and project level factors of location choice decision. Moreover, this study investigates the difference between the degree of innovativeness and routineness of R&D activities offshored to developed and emerging countries. Furthermore, it also looks at the difference between the degree of innovativeness and routineness of R&D activities offshored to foreign affiliate and non-integrated suppliers

    Internet of Things and Sensors Networks in 5G Wireless Communications

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    This book is a printed edition of the Special Issue Internet of Things and Sensors Networks in 5G Wireless Communications that was published in Sensors

    Internet of Things and Sensors Networks in 5G Wireless Communications

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    The Internet of Things (IoT) has attracted much attention from society, industry and academia as a promising technology that can enhance day to day activities, and the creation of new business models, products and services, and serve as a broad source of research topics and ideas. A future digital society is envisioned, composed of numerous wireless connected sensors and devices. Driven by huge demand, the massive IoT (mIoT) or massive machine type communication (mMTC) has been identified as one of the three main communication scenarios for 5G. In addition to connectivity, computing and storage and data management are also long-standing issues for low-cost devices and sensors. The book is a collection of outstanding technical research and industrial papers covering new research results, with a wide range of features within the 5G-and-beyond framework. It provides a range of discussions of the major research challenges and achievements within this topic

    Internet of Things and Sensors Networks in 5G Wireless Communications

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    This book is a printed edition of the Special Issue Internet of Things and Sensors Networks in 5G Wireless Communications that was published in Sensors

    High-precision micro-machining of glass for mass-personalization

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    With the fourth industrial revolution manufacturing industry faces new challenges. Small batches of personalized parts, where the geometry changes per part, must be produced in an economically viable manner. In such cases of mass personalization new manufacturing technologies are required which can keep manufacturing overhead related to change of part geometries low. These processes need to address the issues of extensive calibration and tooling costs, must be able to handle complex parts and reduce production steps. According to recent studies hybrid technologies, including electrochemical technologies, are promising to address these manufacturing challenges. At the same time, glass has fascinated and attracted much interest from both the academic and industrial world, mainly because it is optically and radio frequency transparent, chemically inert, environmentally friendly and it has excellent mechanical and thermal properties, allowing tailoring of new and dedicated applications. However, glass is a hard to machine material, due to its hardness and brittleness. Machining smooth, high-aspect ratio structures is still challenging due to long machining times, high machining costs and poor surface quality. Hybrid methods like Spark Assisted Chemical Engraving (SACE) perform well to address these issues. Nevertheless, SACE cannot be deployed for high-precision glass mass-personalization by industry and academia, due to 1) lack of process models for glass cutting and milling, relating SACE input parameters to a desired output, 2) extensive calibration needed for tool-workpiece alignment and tool run-out elimination, 3) part specific tooling required for proper clamping of the glass workpiece to attain high precision. In this study, SACE technology was progressively developed from a mass-fabrication technology towards a process for mass-personalization of high-precision glass parts by addressing these issues. Key was the development of 1) an (empirically validated) model for SACE cutting and milling process operations allowing direct relation of the machining input to the desired machining outcome, enabling a dramatical increase of automation across the manufacturing process workflow from desired design to establishing of machinable code containing all necessary manufacturing execution information, 2) in-situ fabrication of the needed tooling and 3) the use of low-cost rapid prototyping, eliminating high indirect machining costs and long lead times. To show the viability of this approach two novel applications in the microtechnology field were proposed and developed using glass as substrate material and SACE technology for rapid prototyping: a) fabrication of glass imprint templates for microfabricating devices by hot embossing and b) manufacturing of glass dies for micro-forming of metal micro parts
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