Focused 20 MHz single-crystal piezocomposite ultrasound array
Focused 20 MHz single-crystal piezocomposite ultrasound array
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聚焦 20 MHz 单晶压电复合超声阵列
DOI：
10.1109/ultsym.2009.5441566
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
R. Dufait
中科院分区：
文献类型：
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作者：
C. Bantignies;P. Mauchamp;G. Férin;S. Michau;R. Dufait
PZN-PT 和 PMN-PT 等铅基压电单晶首先由美国海军开发用于水下应用。其出色的压电特性（d33 高达 2000 pC/N，k33 > 90%）使它们对于高端超声换能器非常有价值。因此，它们已在主要用于心脏成像（2-5 MHz）的医疗领域成功使用和商业化，但制造此类探针至关重要，因为单晶结构对标准微加工工艺引起的热应力和机械应力更加敏感。我们在本文中建议使用低应力加工工艺制造基于非常薄的 1-3 单晶复合材料（<70 µm 厚）的高频超声探头（15-20 MHz），并表现出改进的电声性能。本文介绍了基于单晶压电复合材料的超声阵列的声学设计、制造和评估。阵列规格为 3 毫米仰角、100 米间距、20 MHz 中心频率。我们证明了生产具有适合高分辨率成像性能的 PMN-PT 单晶探针的可行性。完整的电声表征已经完成：然后讨论带宽、方向性和压力性能，并与具有相同规格的经典 PZT 探头进行比较。性能与最先进的压电复合材料传感器获得的性能进行了比较，实现了有竞争力的带宽和+6 dB 的灵敏度改进。
Lead-based piezoelectric single crystals such as PZN-PT and PMN-PT have been first developed for under water applications by the U.S. Navy. Their outstanding piezoelectric properties (d33 as high as 2000 pC/N and k33 > 90%) make them valuable for high-end ultrasound transducers. Thus, they have been successfully used and commercialized in medical field mainly for cardiac imaging (2-5 MHz) but manufacturing such a probe is critical since single crystal structures are more sensitive to thermal and mechanical stresses induced by standard micromachining process. We propose in this paper to manufacture a high frequency ultrasound probe (15-20 MHz) based on very thin 1-3 single crystal composite materials (<70 ¿m thick) using low-stressing machining process and exhibiting improved electroacoustical performances. This paper presents the acoustical design, fabrication and evaluation of an ultrasound array based on single crystal piezocomposite. The array specifications were a 3 mm elevation, 100 ¿m pitch, 20 MHz center frequency. We demonstrate the feasibility to produce a PMN-PT single crystal probe with suitable performances for high resolution imaging. A complete electro-acoustical characterization has been done: bandwidth, directivity and pressure performances are then discussed and compared to classical PZT probes with the same specifications. Performances are compared to those obtained with state-of-the-art piezocomposite transducers, achieving competitive bandwidth and an improvement of +6 dB in sensitivity.