Artigos Técnicos e Apresentações

Aqui você encontrará apresentações realizadas nas Conferências de Usuários COMSOL de todo o mundo. As apresentações englobam pesquisas e produtos inovadores feitas por engenheiros e cientistas usando o COMSOL Multiphysics. Os tópicos abramgem uma grande gama de indústrias e aplicações, como elétrica, mecânica, escoamento e química. Use a função de busca "Quick Search" para encontrar apresentações na sua área de interesse.

Applied Multiphysics in Thermoresistive and Magnetoresistive Sensor Models

R.W. Pryor
Pryor Knowledge Systems, Inc.
COMSOL, Certified Partner

Efficient, effective, and functional operation of autonomous systems requires a comprehensive real-time understanding, by those systems, of the embedding environment. This paper presents a brief overview of the multiphysics considerations involved in the development of models for thermoresistive and magnetoresistive sensors systems.

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 ...

Antenna and Plasmonic Properties of Scanning Probe Tips at Optical and Terahertz Regimes

A. Haidary[1], P. Grütter[1], Y. Miyahara[1]
[1]Physics Department, McGill University, Montreal, QC, Canada

A wide variety of near-field optical phenomena such as apertureless near-field scanning microscopy (ANSM) at optical and terahertz (THz) regimes and surface enhanced Raman scattering relies on the electric field enhancement at the end of a sharp tip. Achieving and controlling this electric field enhancement is a key challenge for a wide range of applications such as surface modification, data ...

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 ...

Design and Analysis of MEMS-based direct methanol fuel cell

Z. Yuan
Harbin Institute of Technology, Harbin, China

In this presentation, “Design and Analysis of MEMS-based direct methanol fuel cell,” there are three main model parts, two-dimensional two-phase mass transport model, μdmfc three-dimensional model and a novel cathode model. First, a two-dimensional two-phase mass transport model was established. In this model, the process of gas-liquid transfer and electrochemical reaction within the ...

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