Technical Papers and Presentations

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.

Magnetic Ratchet

A. Auge, F. Wittbracht, A. Weddemann, and A. Hütten
Department of Physics, University of Bielefeld, Germany

Transport phenomena in spatially periodic magnetic systems, in particular the directed transport of magnetic beads in a so called magnetic ratchet (Brownian motor) are considered. Simulations are carried out to test and optimize this system, where the Smoluchowski equation with flux terms for the magnetic and gravitational force is used. Furthermore, experiments are carried out to verify the ...

Micro Cooling of SQUID Sensor

B. Ottosson[1], Y. Jouahri[2], C. Rusu[1], and P. Enoksson[2]
[1]Imego AB, Gothenburg, Sweden
[2]Chalmers University of Technology, Gothenburg, Sweden

The objective of this work has been to realize a feasibility study of a cooling device for a SQUID sensor using liquid nitrogen flowing through micro channels. The design consists of an epoxy cylindrical vacuum vessel skewed by a silicon microchannel heat sink. The SQUID sensor is situated directly on top of the microchannel heat sink. The device is used at room temperature and should be able to ...

Numerical Analysis of the Impact of Geometric Shape Patterns on the Performance of Miniaturized Chromatography Systems

R. Winz[1], E. von Lieres[2], and W. Wiechert[1]
[1]Department of Simulation, University of Siegen, Siegen, Germany
[2]Institute of Biotechnology, Research Centre Jülich, Siegen, Germany

We have implemented a two dimensional chromatography model for the analysis and optimization of structured micro pillar arrays. Dynamic surface interaction of solved molecules is taken into account by the kinetic Langmuir model. Variations of the pillar array geometry lead to deviations in the outlet concentration profiles. These deviations cannot be described by the one dimensional models that ...

FEM Study on Contactless Excitation of Acoustic Waves in SAWDevices

A. K. Namdeo[1], N. Ramakrishna[2], H. B. Nemade[1,2], and R. P. Palathinkal[1]

[1] Department of Electronics and Communication Engineering, Indian Institute of Technology Guwahati, Assam, India
[2] Centre for Nanotechnology. Indian Institute of Technology Guwahati, Assam, India

In this paper a finite element method(FEM) study of a surface acoustic wave (SAW)device excited by electrostatic coupling method is performed by using COMSOL Multiphysics. We have modeled a Rayleigh wave type SAW device by choosing YZ Lithium niobate as the substrate. The effect of external radio frequency (RF) field to the SAW device is analyzed. The effect of distance between the contactless ...

High Coupling Factor Piezoelectric Materials for Bending Actuators: Analytical and Finite Elements Modeling Results

I.A. Ivan[1], M. Rakotondrabe[1], and N. Chaillet[1]
[1]FEMTO-ST Institute, University of Franche-Comte, Besançon, France

New giant piezoelectric factor materials such as PMN-PT and PZN-PT were researched during the last decade and are actually becoming commercially available. As they seem very attractive for actuator designs, we studied their potential in replacing PZT ceramics. In a first comparative approach, we tested a series of classic rectangular composite bimorph structures of different combinations of ...

Simulation of Thermal Sensor for Thermal Control of a Satellite using COMSOL

G. Mangalgiri
BITS Pilani
Zuarinagar, Goa

Spacecrafts have a prime necessity that their temperature be controlled. This paper presents the simulation of a mechanically actuated field effect transistor that is used in a thermal system. It comprises of a composite beam, a piezoelectric substrate and a field effect transistor. The temperature rise causes a deflection in the composite beam thereby causing it to impinge on the piezoelectric ...

Zone sculpting using partitioned electrokinetic injections

Narovlyansky, M.1, Squires, T.M.2, Whitesides, G.M.1
1 Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, U.S.A.
2 Departments of Physics and Applied Mathematics, Caltech, Pasadena, CA

In electrokinetic separations, the narrower and more homogeneous the initial sample plug, the higher the ultimate resolution of the separation. Here we describe a general and versatile method to sculpt low-dispersion, high-fidelity sample zones in microfluidic devices for high resolution electrokinetic separations. In a simple channel intersections microfabricated partitions act to reduce each ...

Viscous damping of a periodic perforated MEMS microstructure when the Reynolds’ equation cannot be applied: Numerical simulations

D. Homentcovschi[1], and R.N. Miles[1]
[1]Department of Mechanical Engineering, SUNY Binghamton, NY

This paper develops a computational model for determining the total damping coefficient for a unit cell of a MEMS microscale device containing a repetitive pattern of holes. The basic cell of the microstructure is approximated by an axi-symmetric domain and the velocity and pressure fields are determined from solutions of the Navier-Stokes equations using the finite element software package ...

Effect of Mass Adsorption on a Resonant NEMS

J. J. Ruz Martinez
Instituto de Microelectronica de Madrid
Tres Cantos
Madrid, Spain

The motion of a resonant NEMS has been widely studied for many different applications such as structural mechanics in engineering, ultra sensitive mass spectrometers or the well known Atomic Force Microscope. The study of the eigenfrequencies of such structures is very important, and nowadays there are good theoretical methods to accurately predict such eigenfrequencies. When a little mass is ...

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 ...

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