5C-5 High Frequency Piezo Composites Microfabricated Ultrasound Transducers for Intravascular Imaging (Invited)

Yuan, Jianren; Jiang, Xiaoning; Cao, Ping; Sadaka, Alain; Bautista, Rick; Snook, Kevin; Rehrig, Paul W.

doi:10.1109/ultsym.2006.83

Cited by 41 publications

(33 citation statements)

References 13 publications

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“…By using triangular pillars, it is possible to operate the fundamental excitation mode within the bandwidth of lateral modes. This study suggests that at high frequencies, triangularpillar composites allow for aspect ratios to be used that are well outside the acceptable range for low-frequency transducers [12]- [16] but can still produce acceptable performance at high frequencies. Essentially, the secondary modes are suppressed not by the conventional method of pushing the modes outside of the operating bandwidth, but by instead spreading the lateral mode energy out over a wide frequency range within the operating bandwidth of the transducer.…”

Section: Introductionmentioning

confidence: 86%

“…at high frequencies, it is very difficult, using conventional diceand-fill techniques, to sufficiently reduce the size/spacing of the composite pillars enough to push the lateral resonances outside the operating bandwidth of the transducer. For example, to push the first lamb-mode frequency as defined by reynolds et al [8] to about 80 MHz (twice the fundamental frequency [16]), while still maintaining a volume fraction of piezoelectric above 25%, a kerf width of approximately 6 μm is required (assuming a typical piezoelectric and epoxy filler). Because the minimum blade width on our dicing saw is 15 μm, lateral resonances are of great concern for center frequencies greater than about 20 MHz.…”

Section: Composite Designmentioning

confidence: 99%

“…The optimal pillar widths actually approach the dimensions of the ceramic grain size, and the smallest dicing saw blade/laser spot sizes that are currently available are too large to create composites with high enough volume fractions. There has, however, been some interesting work with reducing pillar sizes and increasing volume fractions in pMn-pT single crystal transducers using reactive ion etching [16] and also some interesting work in increasing volume fractions by interdigital bonding [17]. However, generally, decreasing the pillar dimensions in conventional dice-and-fill ceramic composites has hit a plateau.…”

Section: Introductionmentioning

confidence: 99%

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Fabrication and performance of high-frequency composite transducers with triangular-pillar geometry

Brown

Chérin

Yin

et al. 2009

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

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A single-element, 40-MHz, 3-mm diameter transducer was fabricated with a geometric focus at 9 mm. The transducer was based on a piezo-composite substrate with triangular-shaped composite pillars. The 2-way bandwidth of 50% and impedance magnitude were in agreement with that predicted using finite-element modeling. A one-way radiation pattern was collected using a needle hydrophone. The one-way -3 dB beamwidth at the geometric focus was measured to be 120 microm and the -3 dB depth of field was 2.5 mm. This is in good agreement with the theoretical predictions of 112.5 microm and 2.4 mm. The triangular-pillar composite transducer was then compared with a transducer with square composite pillars with similar volume fraction of active ceramic. A 9.5 dB reduction in the amplitude of the secondary resonance was found for the triangular-pillar composite as well as a 30% gain in the 2-way pulse bandwidth. A 256-element 30-MHz linear array was fabricated as a preliminary investigation into the use of the triangular pillar as the substrate in a high-frequency linear array transducer. In vivo images were generated with both the single-element and linear-array transducers.

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Section: Introductionmentioning

confidence: 86%

Section: Composite Designmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fabrication and performance of high-frequency composite transducers with triangular-pillar geometry

Brown

Chérin

Yin

et al. 2009

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

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“…1 Over the past decade, significant progresses have been achieved on crystal growth and characterization, [2][3][4][5][6] and new applications [7][8][9][10][11][12][13][14][15] for binary PMN-PT crystals. Despite the excellent properties of PMN-PT single crystals, the relatively low depoling temperature (T R=T 75-97 C), low coercive field (E C 2:5 kV/cm) and low mechanical quality factor (Q M 80) remain concerns for many applications especially those require high drive conditions.…”

Section: Introductionmentioning

confidence: 99%

Crystal growth and property characterization for PIN–PMN–PT ternary piezoelectric crystals

Tian

Han

2014

J. Adv. Dielect.

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Binary piezoelectric crystal Pb(Mg 1=3 Nb 2=3 ÞO 3 -PbTiO 3 (PMN-PT) has excellent dielectric and piezoelectric properties, which has led to the commercialization for medical ultrasound imaging. Recently, there is a growing demand for piezoelectric crystals with improved thermal and electrical properties. Ternary piezoelectric crystals Pb(In 1=2 Nb 1=2 ÞO 3 -Pb(Mg 1=3 Nb 2=3 ÞO 3 -PbTiO 3 (PIN-PMN-PT) have increased depoling temperature and coercive field than binary PMN-PT. To better understand the ternary crystal system and improve crystal properties, we systematically investigated crystal growth of PIN-PMN-PT with modified Bridgman method. Like PMN-PT, PIN-PMN-PT crystals have excellent piezoelectric properties (e.g., k 33 0:87-0.92, d 33 1000-2200 pm/V). Higher PIN content leads to 40 C increase in depoling temperature and more than doubling of coercive field (7.0 kV/cm). Such improvements are advantageous for applications where high temperature and/or high-drive are needed.

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“…This fabrication process was successfully developed by Jiang et al for fabricating high frequency piezoelectric composites as micro-ultrasound transducers. 16,17 A thick layer of nickel was electroplated through the photoresist pattern, forming the hard mask for the further dry etching step, which involved the deep reactive ion etching with chlorine based gases. However, this method is labor intensive and expensive due to the low etching rate and multiple processing steps.…”

mentioning

confidence: 99%

Fabrication and measurement of a flexoelectric micro-pyramid composite

et al. 2014

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A fabrication method by combining precision mechanical dicing and wet etching was developed to prepare micro-pyramid structures based on (Ba0.67Sr0.33)TiO3 ceramics. The effective piezoelectric properties of flexoelectric pyramid structures in ten micrometers scale were investigated and measured through converse flexoelectric effect. The scaling effect of the flexoelectric response was demonstrated as the structure size shrinks down. The results do suggest the great potential of flexoelectric micro pyramids as an alternative to lead-free piezoelectric material.

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5C-5 High Frequency Piezo Composites Microfabricated Ultrasound Transducers for Intravascular Imaging (Invited)

Cited by 41 publications

References 13 publications

Fabrication and performance of high-frequency composite transducers with triangular-pillar geometry

Fabrication and performance of high-frequency composite transducers with triangular-pillar geometry

Crystal growth and property characterization for PIN–PMN–PT ternary piezoelectric crystals

Fabrication and measurement of a flexoelectric micro-pyramid composite

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