L. Wright, G. Memoli, P. Jones, E. Stride
National Physical Laboratory, Teddington, UK
University College London, London, UK
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 ...
S.L. Firebaugh, E.A. Leckie, J.A. Piepmeier, and J.A. Burkhardt
United States Naval Academy, Annapolis, Maryland, USA
Microrobotics has promising applications in microsurgery and microassembly. A challenge in these systems is interfacing with the robot. This project explores crawling robots that are powered and controlled through a global mechanical vibration field. By controlling the frequencies present in the vibration field, the user can then steer the robot. The “robot” has a rectangular body with ...
Beam Structure As an Acoustic Wave Sensor: A Study of the Effect of Sensor Design on Its Sensitivity to Noise
F. Akasheh, A. Biddle, W.S. Shepard Jr., and B.B.B. Zhang
Tuskegee University, Tuskegee, AL, USA
University of Alabama, Tuscaloosa, AL, USA
The detection and identification of the location of a sound source is commonly done using arrays of microphones. A recent new alternative approach has been proposed which involves the use of continuous structures, such as beams or plates, as acoustic wave sensors. The sound wave impinging on the surface of the structure causes it to vibrate and the measured surface displacements can then be used ...
W. R. Kampinga, and Y. H. Wijnant
Reden, Hengelo, Netherlands
University of Twente, Enschede, Netherlands
Three efficient alternatives to the model in COMSOL’s thermoacoustics interface are presented. The higher efficiency of these models are explained from theory and are demonstrated by means of two examples.
G. Rosi, L. Teresi, A. DiCarlo, and F. dell'Isola
LaMS - Università degli Studi Roma Tre, Roma, Italy
Università degli Studi di Roma "La Sapienza", Roma, Italy
Liquid crystals - as all liquids - are generally modelled as incompressible media. In fact, mass-density changes occurring in these mesophases are minuscule and inconsequential in most regimes of interest. However, liquid crystals exhibit also phenomena that call for a more refined theory. In particular, it is experimentally well established that the Fréedericksz transition - i.e., the sudden ...
V.M. Acosta, E. Riera, G. Rodriguez, A. Pinto, A. Cardoni, J.A. Gallego-Juárez
Power Ultrasonics Group, CSIC, Serrano, Madrid, Spain
Pusonics, Arganda del Rey, Madrid, Spain
This work describes the design methodology and development of piezoelectric transducers for applications in fluids with COMSOL_Multiphysics. In these linear models for the acoustic-structure interaction approximate numerical solutions have been obtained. In order to perform the calculations, simplifications are only valid for low-power sound waves. Numerical modeling of piezoelectric transducers ...
Baumann, B.1, Kost, B.1, Groninga, H.2, Wolff, M.1, 2
1 University of Applied Sciences Hamburg, Mechanical and Production Engineering
2 PAS-Tech GmbH, Zarrentin
The photoacoustic effect is based on resonant absorption of light by a sample and the transfer of the excitation energy into thermal energy via inelastic collisions of gas molecules. A modulated irradiation of the sample causes periodic pressure variations that can be detected by a microphone and measured using lock-in technique. Photoacoustic spectroscopy finds many applications in the field of ...
S. Ni, C. Yang Koh, S. Kooi, and E. Thomas
Institute for Soldier Nanotechnologies
Dept. of Materials Science and Eng.
Recently, the concepts of fractal geometry have been introduced into electromagnetic and plasmonic metamaterials. With their self-similarity, structures based on fractal geometry should exhibit multi-band character with high Q factors due to the scaling law. However, there exist few studies of phononic metamaterials having fractal geometry. COMSOL is used to investigate vector elastic and ...
Tohoku Institute of Technology
This paper is in Japanese.
Y.F. Wang, Y.S. Wang, L. Wang
Institute of Engineering Mechanics, Beijing Jiaotong University, Beijing, China
Department of Mechanical Engineering, Østfold University College, Halden, Norway
We show in this paper that by careful design of the geometry of the resonators, complete bandgap with relatively low center frequency can be obtained for 2D and 3D Phononic Crystals with resonators. The generation of the bandgap is due to the local resonance of the unit cell. Spring-mass and spring-pendulum models are developed to predict the boundaries of the complete bandgap. The predicted ...