HIGH FREQUENCY, TWO-DIMENSIONAL, ULTRASONIC TRANSDUCERS

医学研究和临床应用的新领域正在开发中 使用高频(10-100 MHz)超声成像。 用这些频率制作的超声图像具有分辨率 接近20微米。高频在临床上的初步应用 超声波包括对眼睛、血管系统、皮肤和 软骨。 二维成像阵列相对于线性成像阵列提供的优势 阵列的优点在于它们能够动态控制两个波束 方向。此功能减小了图像切片的大小，减少了 相位像差，并提供体积扫描能力。 高频、二维超声换能器阵列还没有 因为很难制造出小型的 结构和较低的传感器元件灵敏度。低敏感度 可以通过使用多层结构来克服，只有化合物 制造上的困难。 我们提出了一种创新的、可扩展的方法来制造低成本、 高频、二维、多层超声换能器阵列 具有低阻抗和高灵敏度。该方法使用反应式 物理气相沉积沉积高质量、致密的钙钛矿型铅 以钛酸锆酸盐(PZT)薄膜为压电材料， 光刻、溅射和掩模的组合，以提供 层间电极和元件互连。 建议的商业应用：Creare将展示一种创新的 一种制造高频、高灵敏度、二次元器件的方法 将对所有人都有利的三维超声成像阵列 生物医学成像领域。这个项目的商业潜力是 一家大型生物医学超声公司的支持证明了这一点。

New areas of medical study and clinical applications are being developed with the use of high frequency (10-100 MHz) ultrasound imaging. Ultrasound images made with these frequencies have resolutions which approach 20 microns. Initial clinical applications of high frequency ultrasound include imaging the eye, the vasculature, the skin, and cartilage. The advantage that two-dimensional imaging arrays offer over linear arrays is that they enable dynamic control of the ultrasound beam in two directions. This capability reduces the size of image slices, reduces phase aberrations, and provides volumetric scanning capability. High-frequency, two-dimensional ultrasonic transducer arrays have not been manufactured because of difficulty in fabricating the small structures and low transducer element sensitivity. The low sensitivity can be overcome by employing multi-layer structures, which only compounds the fabrication difficulties. We propose an innovative, scaleable approach to manufacturing low-cost, high-frequency, two-dimensional, multi-layer ultrasonic transducer arrays with low impedance and high sensitivity. The approach uses reactive Physical Vapor Deposition to deposit high-quality, dense, perovskite lead zirconate titanate (PZT) films as the piezoelectric material and a combination of photolithography, sputtering, and masking to provide the interlayer electrodes and element interconnections. PROPOSED COMMERCIAL APPLICATION: Creare will demonstrate an innovative approach for manufacturing high-frequency, highly sensitive, two- dimensional ultrasonic imaging arrays which will be of benefit in all areas of biomedical imaging. The commercial potential of this project is evidenced by the support of a major biomedical ultrasound company.