SBIR Phase I:A New High-Strain Material for Medical Ultrasound Transducers

这个小型企业创新研究第一阶段项目的目标是设计一种用于医用超声换能器的高应变压电材料。本文研究了弛豫铁电体Pb(Yb0.5Nb0.5)O_3-PbTiO_3(PYbN-PT)。PYbN-PT晶体沿拟立方晶系001取向生长，可以显著提高D31和D33的压电系数。我们的目标是获得001取向单晶的好处，但这是通过溶胶-凝胶薄膜方法来实现的。我们在弛豫铁电体领域的初步研究表明，PYbN-PT的应变明显高于高性能换能器的主要材料--锆钛酸铅(PZT)。此外，这部新电影还有许多其他令人向往的PZT特征。在第一阶段，将开发PYnB-PT，并充分表征其在医用超声中的使用。为了用于医用超声，必须达到至少3-4微米的PYbN-PT膜厚度。拟议的第一阶段优化研究应该能够将超声系统的选择性提高一个数量级以上。该项目的商业应用是在医学超声成像领域。PYbN-PT薄膜将用于提高具有细胞分辨率的医学超声图像的灵敏度。为了达到必要的空间分辨率，传感器必须发射高频、宽带脉冲。随着超声频率的增加，诊断波在人体组织中的衰减增加，因此需要更高的测量灵敏度。这项拟议的研究与开发低成本的眼科、皮肤科和耳鼻喉科成像设备以及冠状动脉病变的血管内评估特别相关。对于这些应用，传感器的灵敏度在疾病的鉴别诊断中起着重要的作用。超声是性价比最高的影像诊断学之一，它在其他医学学科的不断发展满足了重要的社会需求。

This Small Business Innovation Research Phase I project is aimed at engineering a high-strain piezoelectric material for use in medical ultrasound transducers. The proposed work entails investigations of the relaxor ferroelectric Pb(Yb0.5Nb0.5)O3-PbTiO3 (PYbN-PT). A major increase in the d31 and d33 piezoelectric coefficients can be realized by growing rhombohedral PYbN-PT crystals along the pseudocubic 001 orientation. The objective is to attain the benefits of 001 oriented single crystals, but to do so via the sol-gel thin film method. Our initial research in the area of relaxor ferroelectrics shows that PYbN-PT has significantly higher strain than lead zirconate titanate (PZT), the mainstay material of high performance transducers. In addition, the new film has many other desirable features of PZT. In Phase I, PYnB-PT will be developed and fully characterized for use in medical ultrasound. To be useful for medical ultrasound purposes, a PYbN-PT film thickness of at least 3-4 microns must be achieved. The proposed Phase I optimization study should be able to increase ultrasound system selectivity by more than one order of magnitude.The commercial application of this project is in the field of medical ultrasound imaging. The PYbN-PT film will be used to enhance the sensitivity of medical ultrasound images with cellular resolution. To achieve the necessary spatial resolution, the transducer must emit a high-frequency, broadband pulse. As the ultrasonic frequency increases, the attenuation of the diagnostic wave increases in human tissue and there is a need for more measurement sensitivity. The proposed investigation is particularly relevant to the development of low-cost imaging devices for ophthalmology, dermatology, and otolaryngology as well as for the intravascular assessment of coronary pathologies. For these applications, transducer sensitivity plays an important role in the differential diagnosis of disease.. Ultrasound is one of the most cost-effective imaging diagnostics, and its continued development in other medical disciplines satisfies an important social need.