Correction: Design and simulation of a wireless saw\u2013pirani sensor with extended range and sensitivity

The authors wish to make the following erratum to Reference [1]: The Table 2 below contained false reference numbers. The references were corrected. The corrected references are also available below. The authors would like to apologize for any inconvenience caused to the readers by these changes. Table 2. Detection principles and pressure ranges of micro-electro-mechanical system (MEMS) Pirani gauges. (Table Presented)

Design and Simulation of a Wireless SAW-Pirani Sensor with Extended Range and Sensitivity

Pressure is a critical parameter for a large number of industrial processes. The vacuum industry relies on accurate pressure measurement and control. A new compact wireless vacuum sensor was designed and simulated and is presented in this publication. The sensor combines the Pirani principle and Surface Acoustic Waves, and it extends the vacuum sensed range to between 10-4 Pa and 105 Pa all along a complete wireless operation. A thermal analysis was performed based on gas kinetic theory, aiming to optimize the thermal conductivity and the Knudsen regime of the device. Theoretical analysis and simulation allowed designing the structure of the sensor and its dimensions to ensure the highest sensitivity through the whole sensing range and to build a model that simulates the behavior of the sensor under vacuum. A completely new design and a model simulating the behavior of the sensor from high vacuum to atmospheric pressure were established

Energy-aware 3D micro-machined inductive suspensions with polymer magnetic composite core

This paper addresses the issue of Joule heating in micromachined inductive suspensions (MIS) and reports a significant decrease of the operating temperature by using a polymer magnetic composite (PMC) core. The PMC material has a high resistivity, thus inhibiting the formation of eddy currents, and a high permeability, thus guiding the magnetic field more efficiently within the MIS structure. We experimentally study the distribution of the PMC material inside the MIS structure and evaluate the effect of the core from the dependence of the levitation height on the excitation current. The experiments carried on in ambient room temperature demonstrate that the temperature inside the micromachined inductive suspension is reduced to 58°C, which is a record-low temperature compared to other MIS structures reported before

A microwave resonator integrated on a polymer microfluidic chip

We describe a novel stacked split-ring type microwave (MW) resonator that is integrated into a 10 mm by 10 mm sized microfluidic chip. A straightforward and scalable batch fabrication process renders the chip suitable for single-use applications. The resonator volume can be conveniently loaded with liquid sample via microfluidic channels patterned into the mid layer of the chip. The proposed MW resonator offers an alternative solution for compact in-field measurements, such as low-field magnetic resonance (MR) experiments requiring convenient sample exchange. A microstrip line was used to inductively couple MWs into the resonator. We characterised the proposed resonator topology by electromagnetic (EM) field simulations, a field perturbation method, as well as by return loss measurements. Electron paramagnetic resonance (EPR) spectra at X-band frequencies were recorded, revealing an electron-spin sensitivity of View the MathML source3.7·1011spins·Hz-1/2G-1 for a single EPR transition. Preliminary time-resolved EPR experiments on light-induced triplet states in pentacene were performed to estimate the MW conversion efficiency of the resonator

Heteronuclear micro-helmholtz coil facilitates μm-range spatial and sub-Hz spectral resolution NMR of nL-volume samples on customisable microfluidic chips

We present a completely revised generation of a modular micro-NMR detector, featuring an active sample volume of ∗ 100 nL, and an improvement of 87% in probe efficiency. The detector is capable of rapidly screening different samples using exchangeable, applicationspecific, MEMS-fabricated, microfluidic sample containers. In contrast to our previous design, the sample holder chips can be simply sealed with adhesive tape, with excellent adhesion due to the smooth surfaces surrounding the fluidic ports, and so withstand pressures of ∗2.5 bar, while simultaneously enabling high spectral resolution up to 0.62 Hz for H2 O, due to its optimised geometry. We have additionally reworked the coil design and fabrication processes, replacing liquid photoresists by dry film stock, whose final thickness does not depend on accurate volume dispensing or precise levelling during curing. We further introduced mechanical alignment structures to avoid time-intensive optical alignment of the chip stacks during assembly, while we exchanged the laser-cut, PMMA spacers by diced glass spacers, which are not susceptible to melting during cutting. Doing so led to an overall simplification of the entire fabrication chain, while simultaneously increasing the yield, due to an improved uniformity of thickness of the individual layers, and in addition, due to more accurate vertical positioning of the wirebonded coils, now delimited by a post base plateau. We demonstrate the capability of the design by acquiring a1 H spectrum of ∗ \11 nmol sucrose dissolved in D2 O, where we achieved a linewidth of 1.25 Hz for the TSP reference peak. Chemical shift imaging experiments were further recorded from voxel volumes of only ∗ 1.5nL, which corresponded to amounts of just 1.5 nmol per voxel for a 1 M concentration. To extend the micro-detector to other nuclei of interest, we have implemented a trap circuit, enabling heteronuclear spectroscopy, demonstrated by two 1H/13 C 2D HSQC experiments. © 2016 Spengler et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

CD-based microfluidics for primary care in extreme point-of-care settings

We review the utility of centrifugal microfluidic technologies applied to point-of-care diagnosis in extremely under-resourced environments. The various challenges faced in these settings are showcased, using areas in India and Africa as examples. Measures for the ability of integrated devices to effectively address point-of-care challenges are highlighted, and centrifugal, often termed CD-based microfluidic technologies, technologies are presented as a promising platform to address these challenges. We describe the advantages of centrifugal liquid handling, as well as the ability of a standard CD player to perform a number of common laboratory tests, fulfilling the role of an integrated lab-on-a-CD. Innovative centrifugal approaches for point-of-care in extremely resource-poor settings are highlighted, including sensing and detection strategies, smart power sources and biomimetic inspiration for environmental control. The evolution of centrifugal microfluidics, along with examples of commercial and advanced prototype centrifugal microfluidic systems, is presented, illustrating the success of deployment at the point-of-care. A close fit of emerging centrifugal systems to address a critical panel of tests for under-resourced clinic settings, formulated by medical experts, is demonstrated. This emphasizes the potential of centrifugal microfluidic technologies to be applied effectively to extremely challenging point-of-care scenarios and in playing a role in improving primary care in resource-limited settings across the developing world

CAM for Microsystems: managing the evolution from planar CMOS to MEMS

This study identifies critical aspects in the design of a modern information system aimed at the production management of industrial and government R&D cleanroom laboratories. We analyze the differences between competing technologies for microsystems fabrication, such as CMOS modified by micromachining steps. Our analysis covers both the technical and organizational perspective and identify new functions not included in traditional semiconductor CA

Model order reduction for large scale finite element engineering models

Software MOR for ANSYS has been developed at IMTEK in 2003. It allows us to perform model reduction directly to finite element models developed in ANSYS. The goal of the present paper is to describe progress achieved for the last two years and review our publications with application of MOR for ANSYS to various engineering problems for different domains: heat transfer, structural mechanics, thermomechanical models, and acoustics including fluid-structure interaction. We also discuss computational scalability of model reduction and the advanced development such as parametric and weakly nonlinear model reduction

Discrete element study of viscous flow in magnetorheological fluids

Using discrete element simulations, we gain insight into the structure of a magnetorheological fluid (MRF) under shear. In simulations with flat walls, the particles arrange in chains, sheet-like structures, or columns along the magnetic field lines, depending on the strength of the applied external magnetic field. Corresponding to the structure formation, three different types of failure mechanisms can be identified. For the characterization of the different regimes, specific particle coordination numbers are introduced. The three structural regimes can be distinguished and described by means of these coordination numbers. To analyze the contact between the MRF particles and the walls of the shear cell, additional simulations with rough walls have been conducted. The resulting structure formation could be successfully classified by the introduced coordination numbers. Based on the analysis of the shear stress transmission both in the case of flat and rough walls, possibilities for shear stress enhancement for technological applications are discussed