Robust Design and Control of Multi-Axis Thin-film Piezoelectric Scanning Actuators for Deep-Tissue Endoscopic Microscopy

本项目的重点是微型成像仪器用压电薄膜致动器的建模和控制。某些高分辨率成像技术可以相对深入地渗透到生物组织中。通过小型手持和/或内窥镜工具在活体上使用这种能力需要精确控制新型微型致动器，例如那些以薄膜形式沉积在硅片上的基于压电材料PZT的致动器。紧凑的数学模型将被开发来描述薄膜PZT在不同工作频率和幅度下的行为。这将被合并到执行器结构运动的动态模型中，受执行器制造中的变化的影响，来自稳健控制领域的技术将被用于设计对制造误差和压电材料变异性相对不敏感的执行器。最后，基于前述模型的反馈控制器将被设计来使用机载传感测量来调节执行器的运动。所提出的工作将通过支持深部组织光学显微镜系统的小型化到与内窥镜兼容的外形尺寸而产生广泛的影响。这些仪器将使各种关于系统生物学、癌症和过敏性疾病等主题的科学和临床活动成为可能。更好地了解薄膜PZT的行为也可以改进基于压电材料的各种微型执行器，如纳米定位器、微型机器人和光学扫描镜。稳健性设计可以帮助减少微技术因加工和环境变化而导致产量较低或性能有限的敏感性。在教育方面，本科生研究人员将通过针对女性和代表性不足的少数族裔的工程实习计划，大力参与原型设备的实验测试和控制系统的实施。支持还将用于开发和实施密歇根大学底特律地区大学预科工程方案中的工程设计和实验活动。

The focus of this project is to model and control piezoelectric thin-film actuators for miniature imaging instruments. Certain high-resolution imaging techniques can penetrate relatively deeply into biological tissue. Use of this ability with living organisms through small handheld and/or endoscopic tools requires precise control of novel micro-scale actuators, such as those based on the piezoelectric material lead-zirconate-titanate (PZT), deposited as thin-film on silicon wafers. Compact mathematical models will be developed to describe thin-film PZT behavior at varying operating frequencies and amplitudes. This will be incorporated into dynamic models of actuator structural motion subject to variation in actuator manufacturing, and techniques from the field of robust control will be used to design actuators that are comparatively insensitive to fabrication errors and piezoelectric material variability. Finally, feedback controllers based on the preceding models will be designed to regulate actuator motion using on-board sensing measurements.The proposed work will have broad impact by supporting miniaturization of deep-tissue optical microscopy systems to an endoscope-compatible form factor. These instruments would enable a variety of scientific and clinical activities regarding topics such as systems biology, cancer, and allergic disease. Better understanding of thin-film PZT behavior could also improve a variety of micro-scale actuators based on piezoelectric materials, such as nanopositioners, micro-robots, and optical scanning mirrors. Design for robustness could help reduce susceptibility of microtechnologies to poor yield or limited performance due to processing and environmental variability. Educationally, undergraduate researchers will be heavily involved in experimental testing of prototype devices and control system implementation, through engineering internship programs targeting women and underrepresented minorities. Support would also be used to develop and implement engineering design and experimentation activities in the University of Michigan Detroit Area Pre-College Engineering Program.