SBIR Phase II: Thick Piezoelectric Films with Dielectric Constant above 3000

该小型企业创新研究(SBIR)二期项目旨在开发用于高频超声换能器的高介电常数(High-K)厚膜。在高频超声医学成像应用中，厚压电膜技术在制作薄压电元件方面具有很大的吸引力。然而，加工厚度在10-20微米范围内的高质量压电薄膜是一项具有挑战性的工作。此外，由于阵列换能器的电匹配需要，薄膜的介电常数需要达到3000或更高。在之前的一期工程中，我们展示了一种介电常数高于3000的压电厚膜。在这个二期工程中，高K厚膜将被用于开发用于血管内超声(IVUS)成像应用的微型高频单元件和线阵换能器。该项目的更广泛的商业影响将是提供高K厚薄膜的潜力，使微型高频超声换能器的应用成为可能。IVUS是一种医学成像方法，使用专门设计的导管，在导管的远端连接一个微型超声探头，将其插入心脏或冠状动脉，以可视化血管和心脏结构。该项目有望使安装在导管上的超声换能器进一步小型化，并提供更高的分辨率。有了这种预期的导管，外科医生可以更清楚地看到患者的动脉，花费更少的手术时间。此外，较小的尺寸将使手术侵入性较小。此外，该技术还可用于其他应用，如手机射频(RF)滤波器、超声波阀门和调谐设备、液体输送和液滴喷射器、化学和生物医学传感器等。

This Small Business Innovation Research (SBIR) Phase II project aims to develop high dielectric constant (high-K) thick film for high-frequency ultrasonic transducer. Thick piezoelectric film technology is very attractive for the fabrication of thin piezoelectric element in high-frequency ultrasonic medical imaging applications. However, it is challenging to process high-quality piezoelectric film with thickness in the range of 10-20 micrometers. In addition, the film needs to demonstrate dielectric constant of 3000 or higher due to the need of electric matching in fabricating array transducers. In previous Phase I project, a piezoelectric thick film with dielectric constant higher than 3000 was demonstrated. In this Phase II project, the high-K thick film will be utilized to develop miniature high frequency single element and linear array transducers for Intravascular Ultrasonic (IVUS) imaging applications. The broader/commercial impact of this project will be the potential to provide high-K thick film to enable the application of miniature high-frequency ultrasonic transducers. IVUS is a medical imaging methodology using a specially designed catheter with a miniaturized ultrasound probe attached to the distal end of the catheter, which is inserted into the heart or into a coronary vessel for visualizing the vessel and heart structure. This project is expected to further miniaturize the ultrasonic transducer mounted on the catheter and provide improved resolution. With this anticipated catheter, surgeons may view the arteries of patients more clearly and spend less surgery time. Plus, the smaller size will make the procedure less invasive. In addition, this technology can also be used in other applications such as Radio Frequency (RF) filters for cell phone, ultrasonic valve and tuning devices, liquid delivery and droplet ejectors, chemical and biomedical sensors etc.