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

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

Microfluidic system with a wireless paired emitter detector diode device as optical sensor for water quality monitoring

Increased demand for improved water management is driving need for water quality monitoring systems with greatly improved price/performance characteristics. This work presents the first use of wireless paired emitter detector diode device (PEDD) as an optical sensor for colorimetric analysis of water quality in a Lab-on-a-disc device format. The instrument detector involves using two light emitting diodes (LEDs), which act as both a light source and photo detector (Fig. 1a.). In comparison to the more commonly used method of coupling a LED to a photodiode, this technique achieves excellent sensitivity and signal-to-noise ratio, with very low cost fabrication and electronics. Furthermore, its low power consumption, increasing spectral range coverage, excellent intensity and efficiency, small size, ease of fabrication and simplicity of the PEDD make it a perfect optical detector for colorimetric assays [1]. In addition, the device is ideally suited for integration with microfluidic platforms based on the centrifugal Lab-on-a-Disc concept, in which detector difficulties can arise due to the high rotation speed typically used in this approach [2]. In this work the calibration of the system using bromocresol purple (BCP) is demonstrated. Concentration ranges were examined in parallel using UV-Vis spectroscopy as control, and the PEDD system. Similar limits of detection (ca. 2.5x10-4 M, Fig.1b.) were obtained in both cases. However, the PEDD system presented a linear trend over a wider range of concentrations. The experiments demonstrate the potential for the wireless PEDD to be a versatile and cheap alternative optical detector system for water quality monitoring in microfluidic applications

Applications of micro-fluidic platforms integrating packed stationary phases

To design and fabricate novel centrifugal micro-fluidic platforms integrating packed stationary phases for solid-phase micro-extraction in a wide range of (bio)analytical applications. To design and fabricate novel micro-fluidic platforms integrating packed stationary phases capable of withstanding significant high pressures

Implementing a design thinking approach to de-risk the digitalisation of manufacturing SMEs

Industry 4.0 (I4.0) has proposed a significant shift in the way companies approach manufacturing. However, this new paradigm is not without faults. The integration of processes and equipment (‘digitalisation’) can be prohibitively expensive or too technically complex for small-to-medium enterprises (SMEs) with limited resources and technical expertise. Another barrier to digitalisation lies in the ambiguity of not knowing what precise practices to adopt to improve productivity. Although these challenges have been identified in the literature, there is still little evidence on how to tackle them. Thus, we explore how design thinking can help overcome these challenges, given that it has been used in many organisations and disciplines to deal with complex and ambiguous problems. We do so by investigating the research question ‘How can designers and design thinking processes assist manufacturing SMEs’ digitalisation?’ We address this research question by presenting a case study of a university–industry collaboration where the authors utilised a design-thinking process to select and implement technologies to capture, process and analyse data for an Australian medical device manufacturer. By reflecting on the case study, we identified the user-centeredness of design thinking as crucial in selecting technologies for implementation that prioritised usability and brought value to all stakeholders. Furthermore, iterative prototyping was critical to scale up the required expertise and deliver a successful sustainable solution without investing vast resources. Our work suggests that designers and design thinking have the potential to help de-risk digitalisation. Finally, we suggest a framework that may assist in guiding other SMEs approaching digitalisation and provide a starting point for further design thinking research in this area

Novel optical sensing system based on wireless paired emitter detector device for lab on a disc water quality analysis

This work describes the first use of a wireless paired emitter detector diode (PEDD) as an optical sensor for water quality monitoring in a lab-on-a-disc device. The microfluidic platform, based on a pH dye/ionogel sensing area combined with a low-cost, wireless optical sensor, PEDD, is applied for monitoring the pH and the degree of turbidity of water samples in real time. Calibration of the system resulted in a linear response that obeys the Beer-Lambert Law. A reasonable correlation between water pH results obtained using the PEDD system and a standard pH-meter was obtained

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

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

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)

Optical sensing system based on wireless paired emitter detector diode device and ionogels for lab-on-a-disc water quality analysis

This work describes the first use of a wireless paired emitter detector diode device (PEDD) as an optical sensor for water quality monitoring in a lab-on-a-disc device. The microfluidic platform, based on an ionogel sensing area combined with a low-cost optical sensor is applied for pH (quantitative) and qualitative turbidity monitoring of water samples at the point-of-need. The autonomous capabilities of the PEDD system, combined with the portability and wireless communication of the full device, provide the flexibility needed for on-site water testing. Water samples from local fresh and brackish sources were successfully analysed using the device, showing very good correlation with standard bench-top systems

Novel wireless system for in-situ lab-on-a-disc multi-parameter water quality analysis

Miniaturisation of analytical devices through the advent of micro-fluidics is an important step forward in environmental monitoring, since sample accessing, reagents addition, measurements and calibration can be replicated on a micro-scaled equivalent to bench instrument. Micro-Total-Analysis-Systems (mTAS) provide a route to the generation of analytical instruments that can be operated in remote locations, enabling in-situ water analysis. In this paper we present the development and fabrication of a Lab-on-a-Disc multiparameter water quality monitoring system. The micro-fluidic centrifugal platform (CD) offers many advantages over standard Lab-on-a-chip such as the elimination of large power supplies and external pumps. Depending on the design, the CD is applied for the point-of-care detection of different parameters in real samples. A first CD design for pH and turbidity measurements is based on a pH dye/ionogel sensing area, which exhibits a characteristic color change depending on the pH of the solution, whereas another CD design is used for nitrite detection employing the Griess reaction method. The CDs are combined with a low-cost, wireless optical sensor, paired emitter detector device (PEDD), which enables accurate colorimetric measurements. Apart from the low-power detection, the integration of a wireless communication device allows the acquisition of parameters to be controlled remotely and to be adjusted according to individual needs, in addition to enabling data transfer. Real samples collected from different estuaries in Ireland and Tolka river were tested in terms of pH, turbidity and nitrite concentration. Strong correlations between the results obtained using the PEDD and a standard UV-Vis spectrophotometer were obtained