51 research outputs found

    A violent debate: could guns be made at home by 3D printers?

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    Gun laws have been back in the media recently due, largely, to the horrific events at Sandy Hook Elementary School on December 14, 2012 which claimed the lives of 20 children and six adults. In response President Obama has just unveiled gun control proposals

    3D Printing - To print or not to print? Aspects to consider before adoption - A supply chain perspective

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    3D printing is believed by many to be the next industrial revolution. The technology is already deployed in production. However, supply chain literature is still in its infancy regarding this topic, despite 3D printings radical impact on supply chains. A framework has been developed to assess various aspects that need to be considered when deploying such technology as part of the production process. Literature has been drawn from cross-discipline (e.g. social sciences, engineering, and business). The challenge for businesses will be whether to incur the cost impact today or the opportunity cost of tomorrow if 3D printing is not adopted

    Electrical conductivity, impedance, and percolation behavior of carbon nanofiber and carbon nanotube containing gellan gum hydrogels

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    The electrical impedance behavior of gellan gum (GG), GG-carbon nanotube, and GG-carbon nanofiber hydrogel composites is reported. It is demonstrated that the impedance behavior of these gels can be modeled using a Warburg element in series with a resistor. Sonolysis (required to disperse the carbon fillers) does not affect GG hydrogel electrical conductivity (1.2 ± 0.1 mS/cm), but has a detrimental effect on the gel\u27s mechanical characteristics. It was found that the electrical conductivity (evaluated using impedance analysis) increases with increasing volume fraction of the carbon fillers and decreasing water content. For example, carbon nanotube containing hydrogels exhibited a six- to sevenfold increase in electrical conductivity (to 7 ± 2 mS/cm) at water content of 82%. It is demonstrated that at water content of 95 ± 2% the electrical behavior of multiwalled nanotube containing hydrogels transitions (percolates) from transport dominated by ions (owing to GG) to transport dominated by electrons (owing to the carbon nanotube network)

    CMAS: Fully integrated portable Centrifugal Microfluidic Analysis System for on-site colorimetric analysis

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    A portable, wireless system capable of in situ reagent-based colorimetric analysis is demonstrated. The system is based on a reconfigurable low cost optical detection method employing a paired emitter detector diode device, which allows a wide range of centrifugal microfluidic layouts to be implemented. Due to the wireless communication, acquisition parameters can be controlled remotely and results can be downloaded in distant locations and displayed in real time. The stand-alone capabilities of the system, combined with the portability and wireless communication, provide the flexibility crucial for on-site water monitoring. The centrifugal microfluidic disc presented here is designed for nitrite detection in water samples, as a proof of principle. A limit of detection of 9.31 ppb, along with similar coefficients of correlation and precision, were obtained from the Centrifugal Microfluidic Analysis System compared with the same parameters measured using a UV-Vis spectrophotometer

    Solvent-selective routing for centrifugally automated solid-phase purification of RNA

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    The final publication is available at Springer via https://doi.org/10.1007/s10404-014-1477-9.We present a disc-based module for rotationally controlled solid-phase purification of RNA from cell lysate. To this end, multi-stage routing of a sequence of aqueous and organic liquids into designated waste and elution reservoirs is implemented by a network of strategically placed, solvent-selective composite valves. Using a bead-based stationary phase at the entrance of the router, we show that total RNA is purified with high integrity from cultured MCF7 and T47D cell lines, human leucocytes and Haemophilus influenzae cell lysates. Furthermore, we demonstrate the broad applicability of the device through the in vitro amplification of RNA purified on-disc using RT-PCR and NASBA. Our novel router will be at the pivot of a forthcoming, fully integrated and automated sample preparation system for RNA-based analysis.Peer reviewe

    The ultimate iron chef - when 3D printers invade the kitchen

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    Printing food seems more like an idea based in Star Trek rather than in the average home. But recent advances in 3D printing (known formally as additive manufacturing) are driving the concept closer to reality. With everything from printed metal airplane wings to replacement organs on the horizon, could printed food be next? And how will we feel when it\u27s served at the table

    Three-dimensional printing fiber reinforced hydrogel composites

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    An additive manufacturing process that combines digital modeling and 3D printing was used to prepare fiber reinforced hydrogels in a single-step process. The composite materials were fabricated by selectively pattering a combination of alginate/acrylamide gel precursor solution and an epoxy based UV-curable adhesive (Emax 904 Gel-SC) with an extrusion printer. UV irradiation was used to cure the two inks into a single composite material. Spatial control of fiber distribution within the digital models allowed for the fabrication of a series of materials with a spectrum of swelling behavior and mechanical properties with physical characteristics ranging from soft and wet to hard and dry. A comparison with the rule of mixtures was used to show that the swollen composite materials adhere to standard composite theory. A prototype meniscus cartilage was prepared to illustrate the potential application in bioengineering

    3D printing and the third mission: The university in the materialization of intellectual capital

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    The production, diffusion and preservation of knowledge are the main goals of universities, which are critical nodes for mediating intellectual capital. In recent years, 3D printing (additive manufacturing) technologies are emerging as a possible disruptive or transformative force in the knowledge economy and by extension the material economy as consumers are given the affordance of materializing information into real-world objects. To understand the role universities will play in this potential convergence of the material and knowledge economies, this paper surveys current levels of involvement of tertiary institutions in 3D printing. The paper projects how the materialization of data will affect a range of social dynamics for creators-cum-consumers at different scales: community, region and nation-state and applies case studies to the multilevel perspective (MLP) framework. Studies are considered in three empirical cases: Berlin in Germany, Lancashire in the United Kingdom, and the United States. The research indicates that the National Additive Manufacturing Innovation Institute (NAMII) \u27America Makes\u27 Program is a top-down knowledge dissemination program for 3D printing. In contrast, the UK Lancaster University Product Development Unit (LPDU) is a 3D-printing value-network, which has developed organically over a decade of operation. Fablab Berlin is a local initiative loosely coupled with industry and tertiary education providers. The paper proposes a future-oriented conceptual framework to capture a variety of present-day university engagements with additive manufacturing in terms of intellectual capital

    Three dimensional (3D) printed electrodes for interdigitated supercapacitors

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    Common fabrication techniques typically require multiple and complex MEMS processing steps to create 3D electrode architectures. Here we report on the use of Additive Fabrication metal printing based on Selective Laser Melting (SLM) technology to produce 3D titanium interdigitated electrodes. This was used as a platform to deposit polypyrrole and the resultant structure was evaluated for use as a capacitive electrode. We also demonstrate a solid-state interdigitated supercapacitor using a poly(vinyl alcohol) (PVA)-H3PO4 polymer electrolyte
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