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

该小型企业创新研究第一阶段项目旨在设计用于医疗超声换能器的高应变压电材料。本论文主要研究了弛豫铁电体Pb（Yb0.5Nb0.5）O3-PbTiO 3（PYbN-PT）。通过沿沿着伪立方001取向生长菱面体PYbN-PT晶体，可以实现d31和d33压电系数的大幅度提高。目标是获得001取向单晶的益处，但是通过溶胶-凝胶薄膜方法来实现。 我们在弛豫铁电体领域的初步研究表明，PYbN-PT具有显着更高的应变比锆钛酸铅（PZT），高性能换能器的支柱材料。此外，新的薄膜具有PZT的许多其他可取的功能。在第一阶段，PYnB-PT将被开发并充分表征用于医学超声。为了可用于医疗超声目的，必须实现至少3-4微米的PYbN-PT膜厚度。建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薄膜将用于增强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，换能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，并且需要更高的测量灵敏度。拟议的调查是特别相关的低成本成像设备的眼科，皮肤科，耳鼻喉科以及冠状动脉病变的血管内评估的发展。对于这些应用，传感器灵敏度在疾病的鉴别诊断中起着重要作用。超声是最具成本效益的影像诊断之一，其在其他医学学科的持续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.