【作者】 缪兴华；

【导师】 汪炜；

【作者基本信息】 南京航空航天大学 ， 机械制造及其自动化， 2019， 博士

【摘要】 微悬臂梁是微机电系统中的常用结构,广泛应用于微调制器、微制动器、微能量采集器、微机械开关等各类微小型器件及设备。传统微悬臂梁加工多采用基于硅的微细加工技术,生产成本高、工艺复杂、制备过程中使用的腐蚀剂等对环境有污染、腐蚀精度不易控制。超薄玻璃以其轻薄、透光率高、光电性能好、耐腐蚀等优点在室内建筑、可穿戴设备、智能手机、平板电脑、能量存储等领域应用广泛,但用作微悬臂梁的基体材料鲜有报道。针对超薄玻璃微悬臂梁制备的难题,本文构建了基于超声振动系统等效阻抗控制策略的微细超声加工系统,采用微细超声加工方法制备了超薄玻璃微悬臂梁,并以超薄玻璃微悬臂梁为基体制备PBZ铁电薄膜,利用逆压电效应研究了超薄玻璃微悬臂梁的机械特性。论文完成的具有创新意义的研究工作主要包括:（1）分析了微细超声加工电源的负载特性,自主研发了基于DSP的功率为100W、输出电流峰峰值为0～1200m A的微细超声加工用可编程恒流超声电源。性能测试结果表明,该电源在频率跟踪、功率可调、电流输出及阻抗匹配等方面均能满足微悬臂梁微细超声加工要求。（2）分析了超声振动系统等效阻抗与加工力和加工间隙的关系,结合超声加工自动进给调节特性,提出基于超声振动系统等效阻抗的微细超声加工自动进给控制策略,阐明了该控制策略的基本原理,在此基础上,设计并实现了基于该控制策略的自动进给调节系统。试验结果表明,该自动进给调节系统响应速度快、加工稳定性高。（3）研究了超声振动系统的负载阻抗特性,设计制作了微悬臂梁微细超声加工用的超声振动系统（压电换能器、超声变幅杆和工具头统称）。利用ANSYS软件对超声变幅杆模态进行分析,测试结果表明,组装后超声振动系统的谐振频率与设计仿真结果偏差<0.5%。（4）综合利用以上研究成果,构建超薄玻璃微悬臂梁微细超声加工系统,制备出长宽尺寸小于1000μm、最小厚度为180μm的超薄玻璃微悬臂梁阵列。通过微细超声微小孔加工试验、超薄玻璃微悬臂梁制备试验,研究了基于等效阻抗控制策略的微细超声加工系统的阻抗控制规律。（5）提出采用溶胶-凝胶法在超薄玻璃微悬臂梁基体上制备压电薄膜的工艺路线,压电薄膜电学性能测试结果表明,PBZ-La Ni O₃结构具有比较理想的电滞回线。利用ANSYS软件仿真研究了微悬臂梁基体厚度、压电薄膜厚度对微悬臂梁固有频率的影响,仿真结果的变化趋势与基于逆压电效应的测试结果基本一致,为超薄玻璃压电微悬臂梁在MEMS领域的广泛应用提供了试验依据。更多还原

【Abstract】 Microcantilever is a common structure in Micro Electro Mechanical System（MEMS）,which is widely used in micro modulator,micro brake,micro energy collector,micro mechanical switch and other micro devices and equipment.Traditional microcantilever beam processing mostly adopts silicon micromachining technology,which has high production cost,complicated process,environmental pollution caused by corrosive agents used in the preparation process and difficult control of corrosion precision.Ultra-thin glass is widely used in indoor buildings,wearable devices,smart phones,tablet computers,energy storage and other fields due to its light weight,high light transmittance,good photoelectric performance,corrosion resistance and other advantages,but it is rarely reported as a substrate material for microcantilevers.In order to solve the problem of preparing ultra-thin glass microcantilever,a micro ultrasonic machining system based on equivalent impedance control strategy of ultrasonic vibration system is constructed in this thesis.Ultra-thin glass microcantilever is prepared by micro ultrasonic machining method,and PBZ ferroelectric thin film is prepared by using ultra-thin glass microcantilever as substrate.The mechanical properties of ultra-thin glass microcantilever are studied by using inverse piezoelectric effect.The innovative research work completed in this thesis mainly includes:（1）The load characteristics of micro ultrasonic machining power supply are analyzed,and a programmable constant current ultrasonic power supply for micro ultrasonic machining based on DSP with power of 100W and output current peak-to-peak value of 0～1200m A is independently developed.The performance test results show that the power supply can meet the requirements of microcantilever micro ultrasonic machining in terms of frequency tracking,power adjustment,current output and impedance matching.（2）The relationship between equivalent impedance of ultrasonic vibration system,machining force and machining gap is analyzed.Combined with the automatic feed adjustment characteristic of ultrasonic machining,an automatic feed control strategy for micro ultrasonic machining based on equivalent impedance of ultrasonic vibration system is proposed,and the basic principle of the control strategy is expounded.On this basis,an automatic feed adjustment system based on the control strategy is designed and implemented.The test results show that the automatic feed adjustment system has fast response speed and high processing stability.（3）The load impedance characteristics of the ultrasonic vibration system are studied,and the ultrasonic vibration system（piezoelectric transducer,ultrasonic horn and tool head）for microcantilever ultrasonic machining is designed and manufactured.The modal of the ultrasonic horn is analyzed by ANSYS software.The test results show that the deviation between the resonant frequency of the assembled ultrasonic vibration system and the design simulation results is less than0.5%.（4）Based on the above research results,an ultra-thin glass microcantilever micro ultrasonic machining system is constructed,and an ultra-thin glass microcantilever array with an aspect size of less than 1000μm and a minimum thickness of 180μm is prepared.The impedance control law of micro ultrasonic machining system based on equivalent impedance control strategy is studied through micro ultrasonic micro-hole machining test and ultra-thin glass microcantilever preparation test.（5）A process route for preparing piezoelectric films on ultra-thin glass microcantilever substrates by sol-gel method is proposed.The electrical performance test results of the piezoelectric films show that the PBZ-La Ni O₃ structure has an ideal hysteresis loop.The effects of the thickness of the microcantilever substrate and the thickness of the piezoelectric film on the natural frequency of the microcantilever are simulated by ANSYS software.The variation trend of the simulation results is basically consistent with the test results based on inverse piezoelectric effect,which provides experimental basis for the wide application of ultra-thin glass piezoelectric microcantilever in MEMS field.更多还原