Piezoelectric devices

Pointon, A. J.

doi:10.1049/ip-a-1.1982.0053

Cited by 13 publications

(7 citation statements)

References 14 publications

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“…Once the electric signal reaches the ultrasound horn, it is converted into a mechanical wave by piezoelectric crystals (which change their static dimensions in response to an electric field[18]) through the tip of the transducer, which is then transmitted to the desired medium. Two characteristics of ultrasound waves are most significant in sonophoresis: the amplitude and the frequency.…”

Section: Introductionmentioning

confidence: 99%

Ultrasound-mediated transdermal drug delivery: Mechanisms, scope, and emerging trends

Polat

Hart

Langer

et al. 2011

Journal of Controlled Release

348

290

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The use of ultrasound for the delivery of drugs to, or through, the skin is commonly known as sonophoresis or phonophoresis. The use of therapeutic and high frequencies of ultrasound (≥ 0.7 MHz) for sonophoresis (HFS) dates back to as early as the 1950s, while low-frequency sonophoresis (LFS, 20 – 100 kHz) has only been investigated significantly during the past two decades. Although HFS and LFS are similar because they both utilize ultrasound to increase the skin penetration of permeants, the mechanisms associated with each physical enhancer are different. Specifically, the location of cavitation and the extent to which each process can increase skin permeability are quite dissimilar. Although the applications of both technologies are different, they each have strengths that could allow them to improve current methods of local, regional, and systemic drug delivery. In this review, we will discuss the mechanisms associated with both HFS and LFS, specifically concentrating on the key mechanistic differences between these two skin treatment methods. Background on the relevant physics associated with ultrasound transmitted through aqueous media will also be discussed, along with implications of these phenomena on sonophoresis. Finally, a thorough review of the literature is included, dating back to the first published reports of sonophoresis, including a discussion of emerging trends in the field.

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Section: Introductionmentioning

confidence: 99%

Ultrasound-mediated transdermal drug delivery: Mechanisms, scope, and emerging trends

Polat

Hart

Langer

et al. 2011

Journal of Controlled Release

348

290

View full text Add to dashboard Cite

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“…Pertinent linear material coefficients for gallium arsenide and boron nitride. 183,184,228,[352][353][354][355][356][441][442][443][444][445][446][447][448][449][450][451][452][453]456,460,468,23,452,457,[581][582][583][584][585][586][587][588][589][590][591] Cubic ρ (Mg/m 𝐸 44 is that for lateralexcitation of shear waves propagating along [100]; see also Tables 4a-d and 9a and b. 273 In cubics, the square of this coupling factor is equal to the following quantities: (𝜀 𝑇…”

Section: Ta B L Ementioning

confidence: 99%

“…[169–171], and Refs. [79, 115, 172–230] provide ample information on the piezoelectric effect in general, early investigations, and early as well as some more modern data and applications.…”

Section: History and Development Of The Subjectmentioning

confidence: 99%

Acoustic properties of piezoelectric cubic crystals

Ballato

2023

Int J Ceramic Engine & Sci

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This paper is offered as a complementary adjunct to the many treatments of the electronic and photonic properties of cubic III–V and II–VI compounds appearing in the literature. These crystals typically exhibit piezoelectricity, due to the molecular dissymmetry, thereby allowing the inclusion of classical mechanical/acoustic features along with the quantum. We discuss the history of this modality and then illustrate its use by applying it to an electro‐elastic problem that has the estimable virtues of having an exact solution, along with wide practical applicability: determination of the piezocoupling values governing the excitation of thickness vibrations in thin cubic films or plates of arbitrary crystallographic orientation by electric fields directed either along, or lateral to, the thickness. Explicit results are given for orientations along the great‐circle paths connecting the principal directions [100], [110], and [111]. The formalism is then applied to GaAs as an example; it is further demonstrated that various results, such as the orientational variations of piezocoupling factors, are generally applicable to other members of the III–V and II–VI families by scaling. Ancillary aspects, such as errors due to misorientations, nonlinearities, and equivalent circuit representations, are described and discussed. This work is dedicated to Gerald W. Farnell (1925–2015), Prof. Emeritus, McGill University, Montréal, Canada.

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“…deflection an and the deflection difference 8 Then it follows from Fig. 7(b) that the can be represented as follows: n The relation between points Pn and Pn+l on the X-Y plane can be represented as follows : coordinate (X,, Yn) on the X-Y plane can successively be calculated from the measured curvature function at the interval of A l .…”

Section: Estimation Of Shapementioning

confidence: 99%

“…These are the features not observed in such early piezoelectric materials as quartz and PZT. The copolymer material is now applied widely to biological transducers such as [7] phonocardiographic microphone and manometer [8].…”

Section: Introductionmentioning

confidence: 99%

Tongue‐Shaped Measurement Using Piezoelectric Thin Film

Matsumura

Fujii

1988

Systems & Computers in Japan

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A tongue‐shaped measuring system was developed using a polymer piezoelectric film to analyze the tongue motion in harmonization of utterance. The copolymer piezoelectric film has a bimorph structure and produces a voltage proportional to the curvature of the tongue. By attaching the film on the tongue, the curvature at each point on the surface is measured, and the shape of the tongue is calculated from the curvature. To evaluate the shape measurement using the developed system, a simulator for the tongue shape was constructed, which has a curved surface of curvature between −0.4 to −0.57 cm−1. The shape of the simulator was measured. It was verified as a result that the error of estimation along the normal direction of the surface is within 0.5 mm, which is sufficient for the measurement of the tongue shape. Then the developed system was applied to measure the shape of the median and the frontal shape of the tongue during utterance. It is shown that the shape of the tongue during utterance can be measured. In the case of median shape, the curving. process from the main part to the tongue tip during the utterance of /r/ was clearly measured. The frontal shape, which has been difficult to measure, can easily be measured as in the case of the median shape, by modifying the placement of the copolymer piezoelectric film. The concave shape on the median line of the tongue during vowel harmonization was observed clearly.

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Piezoelectric devices

Cited by 13 publications

References 14 publications

Ultrasound-mediated transdermal drug delivery: Mechanisms, scope, and emerging trends

Ultrasound-mediated transdermal drug delivery: Mechanisms, scope, and emerging trends

Acoustic properties of piezoelectric cubic crystals

Tongue‐Shaped Measurement Using Piezoelectric Thin Film

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