Micromachined Single Crystals for HF Transducers

用于高频传感器的微机械单晶

• 批准号: 6689782
• 负责人: Wesley S. Hackenberger
• 金额: $ 10万
• 依托单位: TRS TECHNOLOGIES, INC.
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2004-06-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6689782
• 关键词: bioimaging /biomedical imaging; biomedical equipment development; electrical property; image enhancement; miniature biomedical equipment; ultrasound

DESCRIPTION (provided by applicant): High frequency ultrasound is needed for high resolution imaging applications in dermatology, ophthalmology, intravascular imaging, and laproscopy. The purpose of the proposed effort will be to develop a novel lithography-based micromachining method for single crystal piezoelectrics in order to fabricate 2-2 and 1-3 composite transducers capable of operating at frequencies from 20 MHz to greater than 50 MHz. Single crystal piezoelectrics have considerably higher piezoelectric coefficients and electromechanical coupling factors than PZT ceramics, and as a result they are being used to fabricate ultrasound transducers with unprecedented bandwidth and sensitivity. Application of single crystal piezoelectrics to high frequency transducers is expected to result in devices with much larger depths of field, limits on which are a significant draw back for existing high frequency transducers. In addition use of single cyrstals, as opposed to ceramic, allows fabrication by lithography based micromachining methods. Thus, very fine featured crystal-polymer composite transducers can be easily fabricated at reasonable cost. In this program both wet etching and reactive ion etching will be investigated as methods for micromaching 2-2 and 1-3 crystal-polymer composite structures for ultrasound transducers. The resulting transducers are expected to have bandwidths in excess of 100% with sensitivities even better than current ceramic transducers operated below 20 MHz. This would be an unprecedented advance for high frequency ultrasound imaging and would lead to greatly improved diagnostic capability in applications ranging form early stage glaucoma detection to biopsy or melanoma tumor histology.

描述（由申请人提供）： 高频超声在皮肤科、眼科、血管内成像和腹腔镜检查中的高分辨率成像应用中是必需的。提出的努力的目的将是开发一种新的光刻为基础的单晶压电微加工方法，以制造2-2和1-3复合换能器能够在20 MHz到大于50 MHz的频率下工作。单晶压电陶瓷具有比PZT陶瓷高得多的压电系数和机电耦合因子，因此它们被用于制造具有前所未有的带宽和灵敏度的超声换能器。将单晶压电体应用于高频换能器预期会导致具有大得多的场深度的设备，对场深度的限制是现有高频换能器的显著缺陷。此外，与陶瓷相反，使用单晶体允许通过基于光刻的微机械加工方法进行制造。因此，可以以合理的成本容易地制造非常精细特征的晶体-聚合物复合换能器。在这个项目中，湿法刻蚀和反应离子刻蚀将作为超声换能器的2-2和1-3晶体聚合物复合结构的微加工方法进行研究。由此产生的换能器预计将具有超过100%的带宽，灵敏度甚至优于当前低于20 MHz的陶瓷换能器。这将是高频超声成像的一个前所未有的进步，并将大大提高从早期青光眼检测到活检或黑色素瘤肿瘤组织学的应用中的诊断能力。