Micromachined Piezoelectric 2-D Arrays for 3-D Medical Imaging

描述(由申请人提供)：三维超声成像是医学成像中最重要的挑战之一，也是潜在的回报努力。为了保留超声的传统优势，如心脏运动等动态生物过程的可视化，有必要将扫描建立为一种纯粹的电子过程。要实现这一成就，二维阵列是必要的，尽管这些器件的制造存在巨大的挑战。为了获得高质量的图像，必须达到良好的节距，尽管得到的元件具有非常高的电阻抗，并且与电子设备的匹配性很差。由于这些元素的数量和方向很大，很难连接到这些元素，而对如此精细的结构进行切割往往会导致元素缺失。为了克服这些问题，TRS建议使用一种新的基于光刻的深腐蚀方法来制作多层单晶二维阵列。这种方法不仅可以提供较低的阻抗元件和减少制造过程中的机械应力，而且由于压电单晶体的优异性能，还可以提供固有的更好的成像。在第一阶段，TRS将为单层和多层1.5-D阵列建立深度蚀刻，该阵列可以支持5 MHz及以上的频率，通过机械加工进行开发以支持2-D元素，并优化晶体多层的光刻方法。在第二阶段，TRS希望与医疗行业合作伙伴共同开发一种2-D阵列换能器。

DESCRIPTION (provided by applicant): Three dimensional ultrasound imaging is one of the most significant challenges, and potentially rewarding efforts, in medical imaging. To retain the traditional benefit of ultrasound, visualization of dynamic biological processes such as heart motion, it is necessary to establish scanning as a purely electronic process. Two dimensional arrays are necessary for this achievement, though there are significant challenges to fabrication of these devices. A fine pitch must be achieved for quality imaging, though the resulting elements possess a very high electrical impedance and poor matching to electronics. Connection to these elements is difficult due to the large number and orientation, and dicing of such fine structures often results in missing elements. To overcome these issues, TRS proposes to make multilayer single crystal 2- D arrays utilizing a new photolithography based deep etching method. This method can not only provide lower impedance elements and a reduction in mechanical stress during fabrication, but also provides inherently better imaging due to the superior properties of the piezoelectric single crystal. During Phase I, TRS will establish deep etching for single and multilayer 1.5-D arrays that can allow for frequencies from 5 MHz and above, develop via machining to allow for 2-D elements, and optimize photolithographic methods for multilayering of crystals. In Phase II, TRS expects to develop a 2-D array transducer in conjunction with a medical industry partner.