Here you will find presentations given at COMSOL Conferences around the globe. The presentations explore the innovative research and products designed by your peers using COMSOL Multiphysics. Research topics span a wide array of industries and application areas, including the electrical, mechanical, fluid, and chemical disciplines. Use the Quick Search to find presentations pertaining to your application area.

The Effect of Electrochemical Micro-Milling by Rotating Magnetic Field

H-Y. Shen[1], H-P. Tsui[1], J-C .Hung[1], S-Y. Lin[2], and B-H. Yan[2]
[1]Metal Industries Research and Development Centre, Taichung, Taiwan
[2]National Central University, Chungli, Taiwan

In this work, the process of micro-channels in electrochemical micro-milling by using rotating magnet assisted helical tool is presented. The results show helical tool and Lorentz force of the rotating magnetic field that enhance the renewal of the electrolyte and machining efficiency. The feed rate can be raised under the magnetic field assisted in terms of experimental results; moreover, the ...

Magnetic Nanoparticles for Novel Granular Spintronic Devices

A. Regtmeier[1], A. Weddemann[2], I. Ennen[3], and A. Hütten[1]
[1]Dept. of Physics, Thin Films and Physics of Nanostructures, Bielefeld University, Bielefeld, Germany
[2]Dept. of Elect. Eng. and Comp. Science, Lab. for Electromagnetic and Electronic Syst., MIT, Cambridge, MA
[3]Institute of Solid State Physics, Vienna University of Technology, Vienna, Austria

Superparamagnetic nanoparticles have a wide range of applications in modern electric devices. Recent developments have identi fied them as components for a new type of magnetoresistance sensor. We propose a model for the numeric evaluation of the sensor properties. Based on the solutions of the Landau-Lifshitz-Gilbert equation for a set of homogeneously magnetized spheres arranged in highly ...

High Field Magnetic Diffusion into Nonlinear Ferrimagnetic Materials

J-W. Braxton Bragg[1], J. Dickens[1], A. Neuber[1], and K. Long[2]
[1]Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, TX
[2]Dept. of Mathematics, Texas Tech University, Lubbock, TX

Ferrimagnetic based, coaxial nonlinear transmission lines (NLTLs) provide a means to generate sub-nanosecond risetime pulses (from nano-second input pulses) or megawatt level high power microwave oscillations, depending on the geometry, material, and external bias fields. This investigation uses the commercially available, finite element solver COMSOL to provide insight into pulse behavior. ...

A Wide Range MEMS Vacuum Gauge Based on Knudsen’s Forces

V. Sista, and E. Bhattarchaya
Microelectronics and MEMS Lab
Department of Electrical Engineering
Indian Institute of technology Madras
Chennai, India

A MEMS based Knudsen’s pressure gauge working in the range of 1e-5 mbar to 10 mbar is designed and simulated in COMSOL. The working principle is based on Knudsen’s forces that arise when two plates are held at different temperatures and their separation is comparable to the mean free path of the ambient gas molecules. The forces change the separation between the plates and capacitance between ...

Effect of Property Distribution on Flow Behavior in Microfluidic System

M. Motosuke
Tokyo University of Science

This presentation includes: * A discussion on the role of properties in the micro-world * A simulation of a temperature-dependent property * A numerical model that investigates the effects of temperature and velocity fields This paper is in Japanese.

Finite Element Evaluation of Surface Acoustic Wave Reflection and Scattering from Topographic Irregularities Comparable with the Wavelength

S. Yankin[1,2], S. Suchkov[2], S. Nikitov[2,3], B. Sveshnikov[2], I. Shatrova [2]
[1]Joint International Laboratory LICS/LEMAC, IEMN UMR CNRS 8520, EC Lille,Villeneuve d’Ascq, France
[2]Saratov State University, Saratov, Russia
[3]Institute of Radio-engineering and Electronics, Russian academy of Science, Moscow, Russia

Design of SAW devices needs the accurate study of the scattering fields, arising from the interaction of SAW with topographic irregularities. To solve this problem FE methods very perspective, because with its help one can take into account the actual geometry of the electrodes and reflectors. This work describes results of original time domain calculation of 2D SAW scattering fields in delay ...

An Assessment of the Suitability of the Body and Adult Head Coils for Transmission during Paediatric Magnetic Resonance Imaging

G.R. Cook[1], M.J. Graves[1], F.J. Robb[2], D.J. Lomas[1]
[1]Department of Radiology, University of Cambridge, Cambridge, United Kingdom
[2]General Electric Healthcare Coils, Aurora, Ohio, USA

MRI offers many advantages over other modalities and its lack of ionizing radiation is important for children, but can be limited by the radio-frequency (RF) coils available. This work calculates Specific Absorption Rate (SAR) and homogeneity of the RF transmit field (B1+) when imaging infants in adult coils. Two birdcage-type coils were loaded by a tissue model and their B1+ homogeneities ...

Simulated Rheometry of a Nonlinear Viscoelastic Fluid

A. Czirják[1], Z. Kőkuti[1], G. Tóth-Molnár[1], P. Ailer[2], L. Palkovics[2], G. Szabó[1]
[1]University of Szeged, Szeged, Hungary
[2]Kecskemét College, Kecskemét, Hungary

In certain cases, the accuracy of measurements with a rotational rheometer can be influenced by inefficient thermal management, by the heat generated in the sample, or by rod-climbing due to the Weissenberg effect. We investigate the effect of these phenomena with simulations in COMSOL Multiphysics®. Our model is based on the axial symmetric (2D) formulation of the two-phase flow with the ...

Simulation of Beam Propagation with Two-photon Absorption in Semiconductor Materials

Syuhei LEE et al.[1]

[1]Chiba University, Chiba, Chiba, Japan

We have studied ultrafast all-optical switching devices based on two-photon absorption, which are expected to have ultrafast response less than 1 ps in wideband and to be independent of polarization of light. In our laboratory, we have obtained the analytical solution for the equation of light propagation in our model that the two-photon absorption occurs in a sample. Though we have used the ...

Simulation of GMR in Granular C/Co Nanoparticles in Agarose - new

P. Hainke[1], D. Kappe[1], A. Hütten[1]
[1]Universität Bielefeld, Bielefeld, Germany

As the importance of nanoparticles is growing more and more, controlling and understanding the properties of nanoparticles became a focus of research. In this field Meyer at al. [1] are researching the GMR effect in granular gels to develop magnetoresistive sensors. The GMR in granular gels is simulated to investigate the physical processes in those systems. As soon as the models coincide with ...