Development of a computer model for an ultrasonic polymer film transducer system

Wilcox, PD; Monkhouse, R.; Cawley, P.; Lowe, M. J. S.; Auld, B. A.

doi:10.1016/s0963-8695(97)00006-6

Cited by 32 publications

(15 citation statements)

References 13 publications

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“…This approach is expected to accurately describe the device's resonant characteristics -more so than common one-dimensional transmission line analysis [25], [26], [27] -due to its ability to account for electroacoustic coupling across two dimensions. In the following, it is assumed that the out-of-plane dimension (y-coordinate) is large compared to the wavelength, which is reasonable for the device depth y = 15 mm corresponding to 10.1 wavelengths at ⌫ = 1 MHz, taking c = 1480 m s 1 .…”

Section: Numerical Acoustic Modellingmentioning

confidence: 99%

Counterpropagating wave acoustic particle manipulation device for the effective manufacture of composite materials

Scholz

Drinkwater

Llewellyn-Jones

et al. 2015

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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Section: Numerical Acoustic Modellingmentioning

confidence: 99%

Counterpropagating wave acoustic particle manipulation device for the effective manufacture of composite materials

Scholz

Drinkwater

Llewellyn-Jones

et al. 2015

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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“…Linear wave propagation is assumed through passive materials, and an acousto-electric solution is used for the electrically active piezoelectric plates (Bui et al 1977). The general approach is the same as the Krimholtz, Leedom and Matthaei equivalent circuit approach (Leedom et al 1971), and a description of the method used here is given in Wilcox et al (1998). The one-dimensional model assumes that the dimensions perpendicular to the propagation direction are large compared with the wavelength.…”

Section: (A) One-dimensional Electro-acoustic Modelmentioning

confidence: 99%

Manipulation of particles in two dimensions using phase controllable ultrasonic standing waves

et al. 2011

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The ability to manipulate dense micrometre-scale objects in fluids is of interest to biosciences with a view to improving analysis techniques and enabling tissue engineering. A method of trapping micrometre-scale particles and manipulating them on a twodimensional plane is proposed and demonstrated. Phase-controlled counter-propagating waves are used to generate ultrasonic standing waves with arbitrary nodal positions. The acoustic radiation force drives dense particles to pressure nodes. It is shown analytically that a series of point-like traps can be produced in a two-dimensional plane using two orthogonal pairs of counter-propagating waves. These traps can be manipulated by appropriate adjustment of the relative phases. Four 5 MHz transducers (designed to minimize reflection) are used as sources of counter-propagating waves in a waterfilled cavity. Polystyrene beads of 10 mm diameter are trapped and manipulated. The relationship between trapped particle positions and the relative phases of the four transducers is measured and shown to agree with analytically derived expressions. The force available is measured by determining the response to a sudden change in field and found to be 30 pN, for a 30 V pp input, which is in agreement with the predictions of models of the system. A scalable fabrication approach to producing devices is demonstrated.

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“…The resonator can create an uniform one-dimensional standing wave field in a liquid medium. The acoustic characteristics of such a structure (impedance and pressure distribution) were successfully predicted by a one-dimensional equivalent network model (1D model) [35,36]. In this paper, the translation of bubbles in a more general multi-bubble environment is presented and the dynamics of bubbles in a weak acoustic standing wave field are discussed in more detail.…”

Section: Introductionmentioning

confidence: 99%

Collective bubble dynamics near a surface in a weak acoustic standing wave field

Cegla²,

Mettin³

et al. 2012

The Journal of the Acoustical Society of America

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The transport of bubbles to a neighboring surface is very important in surface chemistry, bioengineering, and ultrasonic cleaning etc. This paper proposes a multi-bubble transport method by using an acoustic standing wave field and establishes a model which explains the multi-bubble translation by expressing the balance between Bjerknes forces and hydrodynamic forces on a bubble in a liquid medium. An uniform one-dimensional acoustic standing wave field was created by a multi-layered resonator which was designed based on a one-dimensional equivalent network model. A pair of modified Keller-Miksis equation and translation equations, which take into account the influence from boundary surfaces and neighboring bubbles, were used to simulate the bubble translations. The bubble translations were observed by a high speed camera system. Results indicated that the bubble translations were mainly influenced by the acoustic wave field, the boundary, neighboring bubbles, and buoyancy force from the surrounding liquid. The primary Bjerknes force generated by the sound field dominated the bubble translations at the beginning when the bubbles were far away from the boundary. A surge of attractive secondary Bjerknes force from the boundary was seen when the bubbles were approaching the boundary. The attraction force outweighed the primary Bjerknes force within a short distance of the surface and resulted in a faster bubble motion. Besides the forces generated from the acoustic field and the boundary, neighboring bubbles also exerted secondary Bjerknes forces on a target bubble and influenced its translation. Moreover, to optimize the bubble translation in a multi-bubble environment, a parametric study was carried out to investigate the influence of varied bubble size and acoustic pressure amplitudes on the bubble translation. It was found that increasing the size of a bubble can hardly alter its trajectory but only force it to move at a faster speed. An increase of pressure amplitude can also accelerate the bubble motion and enhance the bubble-bubble interaction. The secondary Bjerknes force between two bubbles can switch from an attractive one when they oscillate in phase, to a repulsive one when the bubble oscillations are out of phase. These findings provide an insight into the multi-bubble translation near a surface and can be applied to future bubble motion control studies, especially in drug delivery, sonoporation, and ultrasonic cleaning.

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Development of a computer model for an ultrasonic polymer film transducer system

Cited by 32 publications

References 13 publications

Counterpropagating wave acoustic particle manipulation device for the effective manufacture of composite materials

Counterpropagating wave acoustic particle manipulation device for the effective manufacture of composite materials

Manipulation of particles in two dimensions using phase controllable ultrasonic standing waves

Collective bubble dynamics near a surface in a weak acoustic standing wave field

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