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，并且可能是有益的努力。为了保持超声的传统优势，可视化动态生物过程，如心脏运动，有必要建立扫描作为一个纯粹的电子过程。二维阵列是实现这一目标所必需的，尽管这些设备的制造存在重大挑战。为了获得高质量的成像，必须实现精细的节距，尽管所得到的元件具有非常高的电阻抗和与电子器件的不良匹配。由于这些元件的数量和取向较大，因此与这些元件的连接是困难的，并且切割这种精细结构常常导致元件缺失。为了克服这些问题，TRS提出了利用一种新的基于光刻的深蚀刻方法来制作多层单晶2- D阵列。这种方法不仅可以提供较低的阻抗元件和制造期间机械应力的减小，而且由于压电单晶的上级特性而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，可以允许5 MHz及以上的频率，通过机械加工进行开发，以允许2-D元件，并优化多层晶体的光刻方法。在第二阶段，TRS希望与医疗行业合作伙伴一起开发一种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.