PZT压电薄膜无阀微泵

介绍了一种基于PZT压电薄膜的无阀压电微泵.该微泵利用自制的压电圆型薄膜片作为驱动部件、聚二甲基硅氧烷(PDMS)作为泵膜.本文在对微豕制备工艺研究的基础上,对其性能进行了数值和实验研究.建立了基于扩张管/收缩管理论的无阀微泵的有限元模型.利用MFX-AN-SYS/CFX技术实现了对微泵的双向流固耦合分析.对微泵的锥形角、最小宽度、扩散管长度、泵腔高度进行数值计算,得到了优化参数.数值计算的结果与实际测量的数据进行了比较,验证了仿真的正确性.     

压电陶瓷驱动并联微动机器人的研究

介绍了集精密机械技术，精密测试技术和智能反馈技术于一体的压电陶瓷驱动六自由度并联微机机器人。该微动机器人采用以压电陶瓷为驱动元件和弹性支撑并联机器人的结构形式，具有高频响、高分辨率，结构紧凑，铡度大等优点，实现了机构，驱动、检测一体化，达到纳米级定位精度，是微驱动技术与并联机器人交叉结合的成功尝试。     

硅基PZT压电薄膜微开关的设计和制作

对硅基锆钛酸铅（PZT）压电薄膜微开关进行了结构和版图设计，根据MEMS加工工艺和标准硅基IC工艺的特点，获得了硅基PZT压电薄膜微悬臂梁结构系统工艺流程中的关键工艺技术和典型工艺条件，对多孔硅的选择性生长进行了较为详细的实验研究，最后成功的制备出硅基PZT压电薄膜微开关样品，这对集成化芯片系统的进一步发展打下了必要的良好的实验基础。     

压电薄膜微传感器振动模态的仿真分析

以压电本构方程为基础，建立了压电薄膜微传感器机电耦合的有限元模型，采用有限元分析软件ANSYS7．0对压电薄膜微传感器进行了模态分析，同时分析了压电薄膜微传感器的结构尺寸对振动模态的影响，探讨了影响压电薄膜微传感器工作稳定性和响应速度的关键因素，结果表明为了提高压电薄膜微传感器的工作稳定性和响应速度，应该在符合工艺要求和保证其它特性的前提下，尽量减小微悬臂梁结构长度，增加多晶硅层厚度，限制PZT层厚度，而微悬臂梁宽度的影响较小。     

压电厚膜驱动的高刚度微变形镜的制备

研究制备了一种压电厚膜微变形镜,微变形镜的连续薄膜式单晶硅镜面由61单元压电厚膜致动器阵列驱动.以镜面冲程与工作频带宽为目标,对微变形镜的结构参数进行优化设计,根据优化参数采用硅微加工技术试制了61单元致动器的微变形镜.镜面、压电陶瓷与弹性支撑层厚度分别为100μm、60μm与60μm,单元间距为5mm,通光口径为40 mm.对制备的样品性能进行了测试,微变形镜在100 V电压驱动下变形量约为2.84μm,工作带宽大于10 kHz.测试结果还表明压电厚膜驱动的微变形镜拥有较高刚度,有利于提高镜面初始平面度.     

ZnO压电薄膜的生长与应用

本文实验研究了ZnO压电薄膜的生长与表征,运用XRD和SEM测试了磁控溅射生长的ZnO压电薄膜的C轴择优取向生长情况和晶粒质量,比较了Si、覆盖在si基底上的Al薄膜和SixNy薄膜三种材料衬底以及退火处理对ZnO薄膜的结晶质量的影响.还开发了仍然采用Al作为底电极但用一层SixNy薄膜与ZnO层隔离的MEMS压电器件的微制造工艺,以满足生长高质量的ZnO压电薄膜并与CMOS工艺兼容的要求.     

双重驱动机器人柔性手臂的研究

本文研究了机器人柔性手臂的实验系统,针对柔性臂的振动问题和定位精度问题,提出了在单个关节柔性臂上实现宏／微结合双重驱动的基本思想。用伺服电机实现柔性臂的宏动,用压电陶瓷驱动器实现柔性臂的微动,通过有效地控制伺服电机和压电陶瓷驱动器抑制柔性臂的振动,并完成柔性臂的精密定位。     

基于槽钹形压电复合驱动的仿尺蠖式微型管道机器人

设计了一种基于槽钹形压电复合驱动的仿尺蠖爬行式微型管道机器人。该机器人包括两个Ф8n硼槽钹形压电复合驱动器和一个爬行定位系统,能够在Ф10mm的曲线形管道中自主定位爬行。槽钹形压电复合驱动器驱动能力为自重的4倍,最大爬行速度为41mm／s;爬行定位系统提供了机器人爬行步距的测量,通过实验验证整个爬行系统的定位误差仅为4‰。     

基于PZT薄膜面内极化工作的低应力压电微传声器

本文设计、制作并测试了一种基于压电PZT薄膜面内极化工作的压电微传声器.利用压电薄膜的纵向压电常数,并通过压电微传声器面内电极的设计提高电极间距,以提高压电微传声器的灵敏度.由于基于PZT薄膜的多层结构常具有很大的残余应力,通过5种不同振动膜材料与PZT薄膜的应力匹配实验,研究了降低振动膜应力的方法.结果表明,对于相同尺寸的膜片,PZT/ZrO2/LTO/Si3N4具有最小的变形,其中心处的变形(200 nm)仅为膜片PZT/ZrO2/Si3N4/SiO2中心处变形(17μm)的1%.采用体硅微加工工艺制作了具有方形振动膜(2 mm×2 mm)的压电微传声器结构,采用LTO/Si3N4多层结构作为振动膜结构,方形膜片中心的圆形结构为PZT薄膜,环形叉指结构为Au/Cr电极.压电微传声器在0.15 kHz~6 kHz频率范围内的灵敏度约为0.1 mV/Pa.     

以溶胶-凝胶法PZT薄膜为驱动的微泵研制

采用溶胶-凝胶法(sol-gel)制备技术制作了Pb(Zr,Ti)O3(PZT)压电薄膜,并以PZT薄膜为驱动制作了微泵.采用了V型微阀的微泵主要利用PZT的压电效应.针对微泵的关键结构--复合驱动膜,探索了一种Si/SiO2/Ti/Au/PZT/Cr/Au多层驱动膜结构制备方法,解决了在硅基底上制备PZT薄膜的问题,同时探讨并解决了硅各向异性刻蚀微泵的微驱动腔、单向阀的工艺问题,并通过SEM照片对V型阀和多层驱动膜进行了表征.研究结果表明,采用MEMS技术成功地完成了微驱动器的研制,得到的驱动腔硅杯平坦均匀.在V型阀微泵整体设计中需要的硅片数目少,降低了器件的复杂性,可以满足功耗低、小型化和批量生产的要求.     

A Multidrug Delivery Microrobot for the Synergistic Treatment of Cancer

Multidrug combination therapy provides an effective strategy for malignant tumor treatment. This paper presents the development of a biodegradable microrobot for on-demand multidrug delivery. By combining magnetic targeting transportation with tumor therapy, it is hypothesized that loading multiple drugs on different regions of a single magnetic microrobot can enhance a synergistic effect for cancer treatment. The synergistic effect of using two drugs together is greater than that of using each drug separately. Here, a 3D-printed microrobot inspired by the fish structure with three hydrogel components: skeleton, head, and body structures is demonstrated. Made of iron oxide (Fe₃O₄) nanoparticles embedded in poly(ethylene glycol) diacrylate (PEGDA), the skeleton can respond to magnetic fields for microrobot actuation and drug-targeted delivery. The drug storage structures, head, and body, made by biodegradable gelatin methacryloyl (GelMA) exhibit enzyme-responsive cargo release. The multidrug delivery microrobots carrying acetylsalicylic acid (ASA) and doxorubicin (DOX) in drug storage structures, respectively, exhibit the excellent synergistic effects of ASA and DOX by accelerating HeLa cell apoptosis and inhibiting HeLa cell metastasis. In vivo studies indicate that the microrobots improve the efficiency of tumor inhibition and induce a response to anti-angiogenesis. The versatile multidrug delivery microrobot conceptualized here provides a way for developing effective combination therapy for cancer.     

Microalgae-Based Biohybrid Microrobot for Accelerated Diabetic Wound Healing

A variety of wound healing platforms have been proposed to alleviate the hypoxic condition and/or to modulate the immune responses for the treatment of chronic wounds in diabetes. However, these platforms with the passive diffusion of therapeutic agents through the blood clot result in the relatively low delivery efficiency into the deep wound site. Here, a microalgae-based biohybrid microrobot for accelerated diabetic wound healing is developed. The biohybrid microrobot autonomously moves at velocity of 33.3 µm s⁻¹ and generates oxygen for the alleviation of hypoxic condition. In addition, the microrobot efficiently bound with inflammatory chemokines of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) for modulating the immune responses. The enhanced penetration of microrobot is corroborated by measuring fibrin clots in biomimetic wound using microfluidic devices and the enhanced retention of microrobot is confirmed in the real wounded mouse skin tissue. After deposition on the chronic wound in diabetic mice without wound dressing, the wounds treated with microrobots are completely healed after 9 days with the significant decrease of inflammatory cytokines below 31% of the control level and the upregulated angiogenesis above 20 times of CD31⁺ cells. These results confirm the feasibility of microrobots as a next-generation platform for diabetic wound healing.     

成型压力对0-3型锆钛酸铅/水泥压电复合材料的影响

以快硬硫铝酸盐水泥为基体,以锆钛酸铅(PZT)为功能相,用压制成型法制备出0-3型PZT/水泥基压电复合材料。分析成型压力对PZT/水泥基压电复合材料的压电性和介电性的影响,结果表明:不同粒径PZT颗粒作为功能相的水泥基压电复合材料,成型压力对其压电性和介电性有不同的影响。在30~90 MPa压力范围内,成型压力越大,PZT/水泥压电复合材料的压电应变常数d33和相对介电常数εr均显著提高,这是由于气孔率随压力增大而减少,而压电电压常数g33的变化则与功能相的粒径有关。机电耦合系数也有着不同的变化趋势,对于6μm和126μm PZT/水泥压电复合材料,其机电耦合系数Kt和Kp随压力增大缓慢下降,而对于430μm PZT/水泥压电复合材料则呈上升趋势。当压力达到150 MPa时,其压电性和介电性均急剧减小。     

Bioinspired aquatic microrobot capable of walking on water surface like a water strider

Walking on the water surface is a dream of humans, but it is exactly the way of life for some aquatic insects. In this study, a bionic aquatic microrobot capable of walking on the water surface like a water strider was reported. The novel water strider-like robot consisted of ten superhydrophobic supporting legs, two miniature dc motors, and two actuating legs. The microrobot could not only stand effortlessly but also walk and turn freely on the water surface, exhibiting an interesting motion characteristic. A numerical model describing the interface between the partially submerged leg and the air-water surface was established to fully understand the mechanism for the large supporting force of the leg. It was revealed that the radius and water contact angle of the legs significantly affect the supporting force. Because of its high speed, agility, low cost, and easy fabrication, this microrobot might have a potential application in water quality surveillance, water pollution monitoring, and so on.     

集成工艺中湿法刻蚀对锆钛酸铅性能的影响(英文)

通过将溶胶凝胶法制备的锆钛酸铅(PZT)在非晶态和多晶态进行刻蚀,对比未经刻蚀的PZT性能,研究了集成工艺中湿法刻蚀造成极化和耐久性能退化的机理.PZT的结晶图谱和表面形貌分析发现,湿法刻蚀中产生的非铁电成分由于具有较小的介电常数,降低了铁电材料上分担的有效测试电压,导致刻蚀后PZT极化能力的降低.未刻蚀的PZT翻转1011次后极化值损失约3%,而刻蚀后极化值减小量大于5%.随着尺寸的减小,耐久特性的降低更为明显,100μm×100μm的PZT极化值减小量约为500μm×500μm样品的3倍.高温过程中由于湿法刻蚀而产生的缺陷和空隙在PZT内部重新分布,外加电压下有更多的电子被缺陷和空隙束缚而产生内建电场并钉扎铁电畴,不同器件尺寸的PZT内部缺陷和空隙浓度的变化不同,导致耐久特性随PZT器件尺寸而不同.利用压电特性参数与极化强度的关系,可以解释湿法刻蚀对压电特性造成损伤的原因.     

PZT/P VDF 压电复合材料的制备及其性能研究

用氧化物一步合成法制备了PZT 粉末, X 射线衍射测试结果显示, 它是Zr/T i 为52∶48 的纯四方钙钛矿型结晶相, 并用SEM 观察了PZT 粉末的形貌; 用热分析仪测试了PVDF 的固化温度; 在自制模具上采用模压/烧结工艺获得了六种含PZT 不同体积含量的PZT/ PVDF 复合材料; 对其介电性和压电性的测试表明, 随着PZT体积含量的增加, 电性能参数呈非线性增大, 当PZT 的体积份数超过70% 时, 介电常数E和压电常数d₃₃值迅速增加, PZT 体积份数达到90% 时, 其电性能参数与纯PZT 值接近, 但此时复合材料的脆性较大, 已没有实用价值。     

压电陶瓷粒度分布对锆钛酸铅/聚偏氟乙烯复合材料电性能的影响

将不同粒度的锆钛酸铅(PZT)陶瓷粉进行复配,制成不同粒度分布的PZT陶瓷颗粒,然后与聚偏氟乙烯(PVDF)复合制备不同PZT粒度分布的PZT/PVDF复合材料,研究了复合材料的介电性能和压电性能。结果表明,当陶瓷颗粒体积分数高达70%时,双峰分布复合材料的压电系数可达75 pC·N-1。这是由于双峰分布复合材料中大陶瓷颗粒保持了完整的钙钛矿结构,小陶瓷颗粒填充在大颗粒之间,陶瓷颗粒彼此联接,形成了更多的电-力耦合通道,有效地实现了压电效应的传递。大陶瓷颗粒完整的钙钛矿结构以及大、小颗粒的协同堆砌效应,提高了PZT/PVDF复合材料的电性能。     

电场对PZT/复合材料层合板破坏强度影响的实验研究

采用三点弯曲方法测量在不同外加电场作用下PZT复合材料层合板的破坏强度(MOR),分析得到了正电场能增强PZT复合材料层合板的破坏强度,而负电场降低了PZT复合材料层合板的破坏强度。本文作者还建立了一套AE测试系统来实时探测在加载过程中由于损伤引起的声信号,进而分析并证实了不同载荷下的PZT复合材料层合板的破坏模式,并用超声扫描成像图加以验证。      

用凝胶注模成型制备压电陶瓷体及其电学性能研究

对PZT陶瓷浆料胶体化学特性进行了研究,成功制备了高固相含量低粘度的PZT陶瓷浆料.对含不同分散剂凝胶注模成型PZT样品电学性能的研究及其与普通干压法制备样品的比较表明,成型过程中的各种有机添加剂如单体和交联剂等不会对PZT的性能造成影响,而某些无机成份如选择不当的分散剂,则会起到一种掺杂剂的作用,从而影响成型后样品的各种电学性能.本文结果说明,对于电子陶瓷材料,在应用凝胶注模这种成型方法时,必须考虑各种添加剂可能对样品性能造成的影响     

Blue-shift and intensity enhancement of photoluminescence in lead-zirconate-titanate-doped silica nanocomposites

Transparent PbZr(0.52)Ti(0.48)O(3) (PZT)-doped silica nanocomposites were fabricated via a modified sol-gel process. The nanocomposites were annealed at different temperatures between 740 and 800?°C in order to produce PZT crystallites with different particle sizes. X-ray diffraction analysis indicated that the embedded PZT nanoparticles were crystallized with a perovskite structure while the SiO(2) matrix was still in an amorphous state. Transmission electron microscopy confirmed that the PZT particles were of nanosize with perovskite structure and dispersed within the SiO(2) matrix. Photoluminescence spectra of the samples were measured between 10 and 290?K. The pure silica matrix showed an emission band at 3.20?eV and a weak emission band at 2.65?eV. They were noticeably suppressed in the PZT/SiO(2) nanocomposites. An additional emission band at ～2.30?eV, due to transition within the PZT crystallites, was identified. This emission band showed a large blue-shift with decreasing PZT crystallite size and a substantially enhanced intensity as compared with that of bulk PZT ceramics. Our studies demonstrate the typical quantum size effect of ferroelectric-doped nanocomposites and the large influence of the silica matrix on the PL intensity of the embedded PZT particles.