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.

Detection of Magnetic Particles by Magnetoresistive Sensors

A. Weddemann[1], A. Auge[1], F. Wittbracht[1], C. Albon[1], and A. Hütten[1]
[1]Department of Physics, Thin Films and Physics of Nanostructures, Bielefeld University, Bielefeld, Germany

In this work, we demonstrate the implementation of the micromagnetic equations for the description of ferromagnetic thin films in COMSOL Multiphysics®. We apply our model to magnetoresistive sensors consisting of several soft ferromagnetic layers and their response to magnetic particles. The magnetization dynamic of the particles needs to be described in a similar manner, though due to size ...

Study of Fluid and Mass Adsorption Model in the QCM-D Sensor for Characterization of Biomolecular Interaction

H.J. Kwon[1], C.K. Bradfield[1], B.T. Dodge[1], and G.S. Agoki[1]
[1]Department of Engineering and Computer Science, Andrews University, Berrien Springs, Michigan, USA

Increasing attention has been paid to application of the quartz crystal microbalance with dissipation (QCM-D) sensor for monitoring biomolecular interactions. This paper focuses on a practical application of protein-protein binding affinity measurement at low concentrations and minimal sample sizes (50-200 μl of 20-200 nM), which results in low signal measurement. A model simulating fluid ...

Dynamic Simulation of Electrochemical Etching of Silicon with COMSOL

A. Ivanov[1], U. Mescheder[1]
[1]Furtwangen University, Furtwangen, Germany

In the presented work the dynamic simulation of a silicon anodization process is performed. Two mechanisms of etch form development (diffusion in electrolyte, current flow) are considered and simulated. Influence of electrolyte conductivity and radius of the opening in the masking layer is discussed.

The Effects of the Electrical Double Layer on Giant Ionic Currents through Single Walled Carbon Nanotubes

G. Zhang[1][,][2][,][3], S.L. Bearden [1]
[1]Department of Bioengineering, Clemson University, Clemson, SC, USA
[2]Department of Electrical and Computer Engineering, Clemson University, Clemson, SC, USA
[3]Institute for Biological Interfaces of Engineering, Clemson University, Clemson, SC, USA

Electrofluidic transport through a single walled carbon nanotube (SWCNT) is enhanced by electroosmosis. Electroosmosis is made possible in these devices by the combination of a large slip length within SWCNTs and the interfacial potential at the solution/nanotube interface. A computational model of a SWCNT device was developed using COMSOL Multiphysics to investigate the complete electrical ...

Analyte Capture from Liquid Samples: Size Matters

M. Weber[1], M. Reed[1]
[1]Yale University, New Haven, CT, USA

Arrays of vertical pillars, Micro Purification Chips, have been widely used for analyte capture from liquid samples [Henderson et. al, 2006], [Toner et. al, 2007], [Stern et. al, 2010]. However exact understanding of the capture efficiency mechanisms has not been previously explained. Here we present a model in COMSOL Multiphysics® which calculates analyte capture efficiency based on initial ...

3D-Modeling of Magnetophoretic Separation of Superparamagnetic Dispersions Using COMSOL Multiphysics® Particle Tracing Module

D. Kleinehanding[1], L. Teich[1], C. Schröder[1]
[1]Department of Engineering Sciences and Mathematics, Computational Materials Science & Engineering (CMSE), University of Applied Sciences Bielefeld, Bielefeld, Germany

Magnetophoresis is a process of great interest for novel applications based on magnetic nanoparticles and colloids. Environmental applications like wastewater treatments and pollutant removal, biomedical applications like protein isolation, drug delivery, magnetic hyperthermia for cancer treatment, and magnetic-particle imaging are just a few of the numerous technological areas which exploit the ...

Near-Wall Dynamics of Microbubbles in an Acoustical Trap - new

L. Wright[1], G. Memoli[1], P. Jones[2], E. Stride[3]
[1]National Physical Laboratory, Teddington, UK
[2]University College London, London, UK
[3]University of Oxford, Oxford, UK

Understanding the interactions between microbubbles and surfaces is key to the successful deployment of microbubbles in a range of applications. Two important examples are their use as a drug delivery mechanism, and their potential use of acoustically-driven bubbles as microscale sensors. Drug delivery with bubbles involves sonication at high frequency close to a boundary, and sensing with ...

Simple Finite Element Model of the Topografiner - new

H. Cabrera[1], D. A. Zanin[1], L. G. De Pietro[1], A. Vindigni[1], U. Ramsperger[1], D. Pescia[1]
[1]Laboratory for Solid State Physics, ETH Zürich, Zürich, Switzerland

In our recent experiments we are revisiting the topografiner technology for the imaging of surface topography with a resolution of a few nanometers. In these new technique called Near-Field Emission Scanning Electron Microscopy (NFESEM), low-energy electrons are emitted from a polycrystalline tungsten tip via electric-field assisted tunneling. In order to characterize and improve the ...

Particle Flow Control by Magnetically Induced Dynamics of Particle Interactions

F. Wittbracht[1], A. Weddemann[1], A. Auge[1], and A. Hütten[1]

[1]Department of Physics, Thin Films and Physics of Nanostructures, Bielefeld University, Bielefeld, Germany

In this work, we show that dipolar magnetic coupling can be used to control the particle flow through microfluidic structures without changing the state of motion of the carrier liquid. Also no external magnetic gradient fields are employed; the total external magnetic force applied is therefore zero. The theoretical idea will be tested experimentally. Here, additional effects originating from ...

The Origin of Mass-change Sensitivity within Multi-layered, Non-uniform, Piezoelectrically-actuated Millimeter-sized Cantilever (PEMC) Biosensors: Vibrational Analysis through Experiment and Finite Element Modeling (FEM)

B.N. Johnson[1], and R. Mutharasan[1]

[1]Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania, USA

A 3D finite element model (FEM) of the PEMC sensor was developed to characterize the modes of vibration that have demonstrated high sensitivity to mass-change in experimentally fabricated sensors. The fundamental bending mode of vibration and the 1st bending harmonic are predicted at 10.0 kHz and 86.8 kHz, respectively, within approximately 5 % of the experimentally measured resonances. The ...