Fabrication of Anodic Aluminum Oxide Films and Its Application in MEMS Packaging

封装是MEMS器件生产中最大的问题和挑战，其成本占整个MEMS器件成本的50%～80%。目前MEMS封装技术还存在很多问题，例如在硅金共熔键合工艺中，由于硅和金热膨胀系数的差别，键合晶片在退火过程中会产生内应力，影响晶片的键合质量。本文尝试在硅和金之间加入一层多孔氧化铝薄膜(AAO)，利用多孔氧化铝的孔洞释放键合晶片在退火过程中产生的内应力，提高晶片的键合质量。因此，本文重点研究AAO特别是硅基AAO的制备工艺，实验探索AAO提高晶片键合质量的可行性。硅基多孔氧化铝薄膜制备工艺的关键问题是硅衬底的保护和阳极氧化时间的选择。本文采用两步氧化法成功制备了硅基多孔氧化铝薄膜，并将AAO应用到硅金键合...MEMS packaging is one of the most serious problems and challenges in MEMS device manufacturing, which costs 50-80 percent of money in packaging. Nowadays there are many key problems in MEMS packaging, for example, because of the different heat expanded coefficients, the residual stress of bonding wafer occurs after the anneal process, which influences the bonding quality. In this paper a method, w...学位：工学硕士院系专业：物理与机电工程学院机电工程系_精密仪器及机械学号：20032900

Applied research on SiO_2 deposited by PECVD

研究了PECVD腔内压力、淀积温度和淀积时间等工艺条件对SiO2薄膜的结构、淀积速率和抗腐蚀性等性能的影响。结果表明,利用剥离工艺,并采用AZ5214E光刻胶作为剥离掩模成功制作了约2μm厚的包裹在金属铝柱周围的SiO2隔热掩模。The silicon oxide thin films are deposited on Silicon substrate by PECVD.The influence of the process parameters such as temperature, reactant and time on the quality,deposited rate and etchant-resistant characteristics of the silicon oxide thin films are discussed.The experimental result indicates that 2μm-thick silicon oxide adiabatic films can be prepared successfully by using lift-off technology with AZ5214E photoresist lift-off mask,which is wrapped around the aluminum pillar

Combustion Synthesis and Electrochemical Properties of the Small Hydrofullerene C50H10

通讯作者地址: Xie, SY (通讯作者),Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Coll Chem & Chem Engn, Dept Chem, Xiamen 361005, Peoples R China 3. Xiamen Univ, Sch Life Sci, Xiamen 361005, Peoples R China 电子邮件地址: [email protected]; [email protected] hydrofullerene C50H10 is synthesized by low-pressure benzeneoxygen diffusion combustion. The structure of C50H10 is identified through NMR, mass spectrometry, and IR and Raman spectroscopy as a D5h symmetric closed-cage molecule with five pairs of fused pentagons stabilized by ten hydrogen atoms. UV/Vis and fluorescence spectrometric analyses disclose its optical properties as comparable with those of its chloride cousin (C50Cl10). Cyclic and square-wave voltammograms reveal that the first reduction potential of C50H10 is more negative than that of C50Cl10 as well as C60, with implications for the utilization of C50H10 as a promising electron acceptor for photovoltaic applications.973 projects 2011CB935901 NSFC 21031004 21021061 2077310

干细胞的生物力学研究

干细胞生物力学作为生物力学的重要分支和前沿学科，近年来在力学-生物学、力学-化学耦合等方面取得了重大进展，已成为生物力学乃至生物医学工程最活跃的领域之一，并对发育生物学、干细胞生物学、组织修复、再生医学等相关领域产生重要影响．干细胞具有独特的力学性质，可感知、传递、转导和响应生理力学微环境的改变，从而调控干细胞的生长、分化等功能，体现出典型的力学生物学耦合特征．本文将对干细胞的力学性质与细胞力学模型、在体力学环境对干细胞生长和分化的影响、干细胞对外界力学刺激的响应等方面加以综述

Two Complementary Signaling Pathways Depict Eukaryotic Chemotaxis: A Mechanochemical Coupling Model

Many eukaryotic cells, including neutrophils and Dictyostelium cells, are able to undergo correlated random migration in the absence of directional cues while reacting to shallow gradients of chemoattractants with exquisite precision. Although progress has been made with regard to molecular identities, it remains elusive how molecular mechanics are integrated with cell mechanics to initiate and manipulate cell motility. Here, we propose a two dimensional (2D) cell migration model wherein a multilayered dynamic seesaw mechanism is accompanied by a mechanical strain-based inhibition mechanism. In biology, these two mechanisms can be mapped onto the biochemical feedback between phosphoinositides (PIs) and Rho GTPase and the mechanical interplay between filamin A (FLNa) and FilGAP. Cell migration and the accompanying morphological changes are demonstrated in numerical simulations using a particle-spring model, and the diffusion in the cell membrane are simulations using a one dimensional (1D) finite differences method (FDM). The fine balance established between endogenous signaling and a mechanically governed inactivation scheme ensures the endogenous cycle of self-organizing pseudopods, accounting for the correlated random migration. Furthermore, this model cell manifests directional and adaptable responses to shallow graded signaling, depending on the overwhelming effect of the graded stimuli guidance on strain-based inhibition. Finally, the model cell becomes trapped within an obstacle-ridden spatial region, manifesting a shuttle run for local explorations and can chemotactically "escape", illustrating again the balance required in the complementary signaling pathways

悬浮态上皮细胞粘附的力学-化学耦合模型及数值模拟

上皮细胞通过局部募集上皮性钙粘附蛋白(E-cadherin)建立胞间粘着连接,实验证实该过程受到肌球蛋白皮层张力的调控.为了从系统层面阐明粘着连接形成动力学过程,本文考察皮层张力调控肌动蛋白(F-actin)解聚从而参与E-cadherin级联转导,同时以马达-离合器机制模拟两细胞相互作用,据此构建可反映悬浮态细胞粘附的力学-化学耦合数学模型;对整体包含随机点源的非线性反应-扩散方程组与平衡微分方程耦合系统采取了自行发展的格子Boltzmann-粒子法与蒙特-卡洛法数值求解.数值模拟表明,由收缩性肌球蛋白(myosin-II)拉动胞间E-cadherin成键可提升皮层张力,进而降低F-actin解聚速率﹑锚定更多的E-cadherin;所构成的力学反馈回路展现出时空效应,可帮助E-cadherin在接触区建立初始极性; E-cadherin形成顺式二聚体则将初始极性放大,导致接触区E-cadherin展现起始、快速增长及慢速增长的积聚动力学特征.皮层呈松散结构时刚度较小,可通过延长胞间E-cadherin成键寿命提升张力,而接触区弧度适中时(≈1.2 rad) E-cadherin峰值最高;两者可分别作为启动力学反馈回路及调控粘着连接成熟度的有效手段

基于血管结构的原位肝小叶全域血流动力学解析

目的 特定组织、器官的复杂血管网络与血流动力学决定其生物学功能,但其原位、全域特征解析面临挑战。肝脏功能稳态维持与肝脏基本单元肝小叶的血管结构及血流动力学特征息息相关。虽然肝小叶局部结构与血液动力学特征已有报道,但原位肝小叶全域血流动力学特征仍不清楚。方法 结合组织透明化、共聚焦成像和血管三维重建,表征小鼠原位肝小叶血管结构;结合微观粒子追踪测速(μ-PTV)和图论模型,定量分析肝小叶流速分布。为精准表征全域血管结构和血流动力学特征,将肝小叶沿门静脉(PV)到中央静脉(CV)等分为10个区,沿厚度方向将肝小叶分为3～6层,每层20～25μm。结果 结构方面:肝小叶中间区域肝血窦直径,长度,分叉角度和直线度均小于PV和CV周围区域,该趋势沿厚度方向相似;流场方面:μ-PTV测得的速度特征在PV-CV方向上与结构相反,沿厚度方向逐渐增加。为弥补μ-PTV的稀疏限制,进一步基于肝小叶血管网络,借鉴图论模型,实现了肝小叶全域流速及压力分布的表征,模拟和实验数据一致。结论 本工作通过实验与模拟相结合,实现了原位、全域肝小叶结构及血流动力学表征,不仅为阐明肝小叶血流动力学特征提供数据,还可为解析复杂血管网络流体力学问题提供方法学基础