Riding the waves

A little more than 10 years ago Andreas Manz and Harp Minhas launched the Lab on a Chip journal. Their adventurous initiative has developed into a very successful and high-ranked journal, now established as THE reference journal for lab on chip research, and clearly they, and we, all may be very proud of this achievement

Energy from streaming current and potential

It is investigated how much energy can be delivered by a streaming current source. A streaming current and subsequent streaming potential originate when double layer charge is transported by hydrodynamic flow. Theory and a network model of such a source is presented and initial experimental results are given, showing a supplied power of 20 nW obtained by a pressure difference of 1 atm over a glass porous plug, using a 1-mM KCl solution. It is indicated how the rather low mechanical-to-electrical energy conversion efficiency can be increased

On-Chip Detection of Beads with a New Electrical Impedance Sensor

Electrical impedance measurements in microfluidic chips are used for single cell analysis. Parallel electrodes are more suited than planar ones since the electrical field distribution is more homogenous. Previous studies showed methods to make parallel electrodes by incorporating an additional layer between two glass wafers, making electrical connections to both sides needed. Also alignment of electrodes is necessary, making the fabrication of parallel electrodes more elaborate. Therefore a new, simpler fabrication method is developed for the fabrication of parallel electrode chips by incorporating a floating electrode in the microchannel just by adding one step in the fabrication process. In this way, only one side of the chip contains electrical connections. Finally, electrical impedance measurements with 3 and 6 µm polystyrene beads were done. All beads were detected and we have shown that it is possible to distinguish the two beads sizes from each other with a confidence level of 95%, based on the relative change in the electrical impedance

Preface book Microfluidics for medical applications

Lab-on-a-chip devices for point of care diagnostics have been present in clinics for several years now. Alongside their continual development, research is underway to bring the organs and tissue on-a-chip to the patient, amongst other medical applications of microfluidics.This book provides the reader with a comprehensive review of the latest developments in the application of microfluidics to medicine and is divided into three main sections. The first part of the book discusses the state-of-the-art in organs and tissue on a chip; the second provides a thorough background to microfluidics for medicine, and the third (and largest) section provides numerous examples of point-of-care diagnostics.Written with students and practitioners in mind, and with contributions from the leaders in the field across the globe, this book provides a complete digest of the state-of-the-art in microfluidics medical devices and will provide a handy resource for any laboratory or clinic involved in the development or application of such devices

Nanoscale Electrochemical Sensing and Processing in Microreactors

In this review, we summarize recent advances in nanoscale electrochemistry, including the use of nanoparticles, carbon nanomaterials, and nanowires. Exciting developments are reported for nanoscale redox cycling devices, which can chemically amplify signal readout. We also discuss promising high-frequency techniques such as nanocapacitive CMOS sensor arrays or heterodyning. In addition, we review electrochemical microreactors for use in (drug) synthesis, biocatalysis, water treatment, or to electrochemically degrade urea for use in a portable artificial kidney. Electrochemical microreactors are also used in combination with mass spectrometry, e.g., to study the mimicry of drug metabolism or to allow electrochemical protein digestion. The review concludes with an outlook on future perspectives in both nanoscale electrochemical sensing and electrochemical microreactors. For sensors, we see a future in wearables and the Internet of Things. In microreactors, a future goal is to monitor the electrochemical conversions more precisely or ultimately in situ by combining other spectroscopic techniques