Vibration modes in ultrasonic bessel transducer

Eiras, J. A.; Moreno, E.; Calás, H.; Aulet, A.; Negreira, Carlos; Leija, L.; González, Gibran Rivera

doi:10.1109/ultsym.2003.1293144

Cited by 11 publications

(11 citation statements)

References 4 publications

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“…[33], [34], [35]; while, with regard to the use of annular transducers, one can recall for example Refs. [36], [37], [38], [39], [40], [41]. Among the many existing papers, let us mention Refs.…”

Section: Introductionmentioning

confidence: 99%

Producing acoustic ‘Frozen Waves’: Simulated experiments with diffraction/attenuation resistant beams in lossy media

Prego-Borges¹,

Zamboni‐Rached²,

Recami³

et al. 2014

Ultrasonics

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The so-called Localized Waves (LW), and the "Frozen Waves" (FW), have raised significant attention in the areas of Optics and Ultrasound, because of their surprising energy localization properties. The LWs resist the effects of diffraction for large distances, and possess an interesting self-reconstruction -self-healing- property (after obstacles with size smaller than the antenna's); while the FWs, a sub-class of LWs, offer the possibility of arbitrarily modeling the longitudinal field intensity pattern inside a prefixed interval, for instance 0⩽z⩽L, of the wave propagation axis. More specifically, the FWs are localized fields "at rest", that is, with a static envelope (within which only the carrier wave propagates), and can be endowed moreover with a high transverse localization. In this paper we investigate, by simulated experiments, various cases of generation of ultrasonic FW fields, with the frequency of f0=1 MHz in a water-like medium, taking account of the effects of attenuation. We present results of FWs for distances up to L=80 mm, in attenuating media with absorption coefficient α in the range 70⩽α⩽170 dB/m. Such simulated FW fields are constructed by using a procedure developed by us, via appropriate finite superpositions of monochromatic ultrasonic Bessel beams. We pay due attention to the selection of the FW parameters, constrained by the rather tight restrictions imposed by experimental Acoustics, as well as to some practical implications of the transducer design. The energy localization properties of the Frozen Waves can find application even in many medical apparatus, such as bistouries or acoustic tweezers, as well as for treatment of diseased tissues (in particular, for the destruction of tumor cells, without affecting the surrounding tissues; also for kidney stone shuttering, etc.).

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Section: Introductionmentioning

confidence: 99%

Producing acoustic ‘Frozen Waves’: Simulated experiments with diffraction/attenuation resistant beams in lossy media

Prego-Borges¹,

Zamboni‐Rached²,

Recami³

et al. 2014

Ultrasonics

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“…With respect to the last point, let us observe that, even if the precision requirements that one meets for the annular transducer sizes are tight, and appear as a real challenge to be overcome, nevertheless it is encouraging to know that various successes have been already obtained in similar situations, for example for monolithic [11], piezocomposite [23], and PVDF transducers [26]. More explicitly, let us mention that ultrasonic beams have been technologically synthesized, by superposing Bessel radiations, in interesting works like [27], [28], [13], [29], [30], [31], [32], [33], [34].…”

Section: A Preliminary Introductionmentioning

confidence: 99%

Producing Acoustic 'Frozen Waves': Simulated experiments

L.¹,

Zamboni‐Rached²,

Recami³

et al. 2012

Preprint

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n this paper we show how appropriate superpositions of Bessel beams can be successfully used to obtain arbitrary longitudinal intensity patterns of nondiffracting ultrasonic wavefields with very high transverse localization. More precisely, the method here described allows generating longitudinal acoustic pressure fields, whose longitudinal intensity patterns can assume, in principle, any desired shape within a freely chosen interval 0 ≤ z ≤ L of the propagation axis, and that can be endowed in particular with a static envelope (within which only the carrier wave propagates). Indeed, it is here demonstrated by computer evaluations that these very special beams of non-attenuated ultrasonic field can be generated in water-like media by means of annular transducers. Such fields "at rest" have been called by us Acoustic Frozen Waves (FW). The paper presents various cases of FWs in water, and investigates their aperture characteristics, such as minimum required size and ring dimensioning, as well as the influence they have on the proper generation of the desired FW patterns. The FWs are particular localized solutions to the wave equation that can be used in many applications, like new kinds of devices, such as, e.g., acoustic tweezers or scalpels, and especially various ultrasound medical apparatus.n this paper we show how appropriate superpositions of Bessel beams can be successfully used to obtain arbitrary longitudinal intensity patterns of nondiffracting ultrasonic wavefields with very high transverse localization. More precisely, the method here described allows generating longitudinal acoustic pressure fields, whose longitudinal intensity patterns can assume, in principle, any desired shape within a freely chosen interval 0 ≤ z ≤ L of the propagation axis, and that can be endowed in particular with a static envelope (within which only the carrier wave propagates). Indeed, it is here demonstrated by computer evaluations that these very special beams of non-attenuated ultrasonic field can be generated in water-like media by means of annular transducers. Such fields "at rest" have been called by us Acoustic Frozen Waves (FW). The paper presents various cases of FWs in water, and investigates their aperture characteristics, such as minimum required size and ring dimensioning, as well as the influence they have on the proper generation of the desired FW patterns. The FWs are particular localized solutions to the wave equation that can be used in many applications, like new kinds of devices, such as, e.g., acoustic tweezers or scalpels, and especially various ultrasound medical apparatus.

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“…Transducers using piezoelectric arrays with annular configurations are extensively studied nowadays. [1][2][3][4][5] Their use in medical and industrial applications, as in the case of a linear transducer, is supported by the attributes of the control of the radiation field 1,4) or vibration modes. [5][6][7] In these devices, it is important to know the vibrational characteristics of radial modes, particularly those that affect the behavior of the device.…”

Section: Introductionmentioning

confidence: 99%

“…One method of solving this problem numerically is to use the finite element method (FEM). Eiras et al 4) and Li et al 3) applied this technique in order to analyze radial modes in a Bessel transducer and in a piezoelectric ring transformer, respectively.…”

Section: Introductionmentioning

confidence: 99%

Model for Radial Modes in a Thin Piezoelectric Annular Array

Calás

Moreno

Eiras

et al. 2008

jjap

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Piezoelectric arrays with different connectivities are widely used in actuators, transformers, and special ultrasonic transducers. In this study, the global matrix method is presented to describe the resonance radial modes in thin piezoelectric annular arrays with an arbitrary number of elements. Each annular element of the arrays is modeled as a three-port system with one electrical and two mechanical ports. The cored matrix model for radial modes, in a singular ring, is presented in the form of a translation matrix. The dynamic behavior of two annular arrays, a transformer and a Bessel transducer, is simulated assuming that the major surfaces of each element are stress-free, while the laterals are matched with neighbor elements. Thus, the inner and outer lateral surfaces of the system are loaded with an external medium. The simulated and experimental results are in good agreement when the thickness effects are neglected.

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Vibration modes in ultrasonic bessel transducer

Cited by 11 publications

References 4 publications

Producing acoustic ‘Frozen Waves’: Simulated experiments with diffraction/attenuation resistant beams in lossy media

Producing acoustic ‘Frozen Waves’: Simulated experiments with diffraction/attenuation resistant beams in lossy media

Producing Acoustic 'Frozen Waves': Simulated experiments

Model for Radial Modes in a Thin Piezoelectric Annular Array

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