Silicon Microstructures and Technologies in Separation Science

The development of miniaturized total analysis systems, is driven by the desire to automate sample handling, separation or sensing, and detection of analytical instrumentation. Interest in planar structures for separation techniques, especially capillary zone electrophoresis (CZE), has grown rapidly. Initially most of those structures were realized in quartz, but recently polymers have been used to make planar microchannels. In spite of its attractiveness with respect to the potential integration of electronics and electrochemical and optical detectors, silicon has not been used very often, mainly because of its incompatibility with the high voltages used in CZE. In this contribution, an overview of the advantages and disadvantages of silicon for electroosmotically driven separation techniques is presented. Some silicon-derived insulating microstructures and their potential application in chemical analysis are also shown. The microtechnologies used comprise (deep) dry etching, thin-layer growth and anodic bonding. With this combination it is possible to create high resolution electrically isolating silicon dioxide structures with aspect ratios similar to those possible in silicon. Besides these channel structures, a capillary connector is presented with a very low dead and mixing volume for use in (correlation) electrophoresis, and tested by means of precision of consecutive single injections. Finally, the potential of integrated optical detectors in combination with micro-separation structures is presented

Design of problem-based learning activities in the field of microfluidics for 12- to 13-year-old participants—Small Plumbing!: empowering the next generation of microfluidic engineers

Public engagement activities based on microfluidics are being increasingly delivered and reported on in the literature. Here, we evaluate the success of a novel approach to microfluidics outreach recently undertaken with schoolchildren aged 12–13. Unlike previous work, a problem-based learning approach was adopted whereby participants were asked to design and test a microfluidic system to solve a research challenge. Our aim was to develop understanding of microfluidics design, manufacture and operation via involvement in the full engineering cycle of a product, from ideas to design, and from fabrication to test. This article demonstrates that problem-based learning is a successful method of public engagement with microfluidics, and we share our best practice, including activity design, supporting material produced for the project and an example case study detailing the types of chips produced by the participants. Furthermore, following an evaluation of the activity by all participants recommendations for delivery of this, or similar, activities are provided