Preparation of patterned SiC and SiCN microstructures

With the development of modern science and technology, the importance of small structures or microstructures (such as the fluidic nanostructure or microreactor[1], the in- tegrate circuit in microelectronics[2], the factory in a chip[3,4], etc.) has been incarnated day by day in the fields of microelectronics, micro-optical systems, microanalytical sys- tems, microelectromechanical systems and cytobiology. And the fabrication technique (microfabrication) of the small structures has become the h…     

阵列式微型血红蛋白传感器的研制

利用微加工和微装配技术研制了一种微型的阵列式血红蛋白传感器芯片。该传感器芯片非线性仅为3.67%,检测下限达0.1 mg/mL,同时在1 mg/mL浓度下的灵敏度达70μA;在酸性条件下每个单位的pH值变化引起的误差不大于10%,而且在中性和碱性条件下这种影响几乎消失;温度引起的误差约为0.2μA/℃。传感器芯片具有很好的线性度、很稳定的pH特性和温度特性,能够可靠地对血液中血红蛋白进行有效的测定。研究结果显示,在血红蛋白的测定和消化道出血症的检测等医学领域有很好的应用前景。     

电子散射参数提取的新方法

准确提取电子散射参数是确保纳米级电子束光刻邻近效应校正精度的关键。采用了一种不基于线宽测量和非线性曲线拟合的电子散射参数提取的方法。邻近效应校正的近似函数采用双高斯分布,其中η的提取是基于设计线宽变化与相应曝光剂量之间的线性关系进行拟合而得;α和β的提取则是分别根据前散射和背散射的范围设计特定的提取版图,并根据电子束邻近效应产生的特殊现象进行参数值的确定。根据此方法提取了150nm厚负性HSQ抗蚀剂层在50kV入射电压下的散射参数,并将其应用于邻近效应校正曝光实验中,很好地克服了电子束邻近效应的影响,验证了此方法提取电子束曝光邻近效应校正参数的实用性及准确性。     

Novel electrode materials based on ion beam induced deposition of platinum carbon composites

Untreated and thermally annealed platinum carbon (PtC) composites obtained by ion beam induced deposition (IBID) are physically and electrochemically characterized as novel patternable electrode materials. Energy dispersive X-ray spectroscopy (EDX) and Raman spectroscopy reveal that annealing in ambient atmosphere and at temperatures above 400 °C substantially reduces the amount of carbon within the deposited material. Raman spectra also show that at elevated temperatures carbon rearranges into a more structured graphitic-like phase. Atomic force microscopy (AFM) reveals that after the annealing procedure the surface structure appears more corrugated, while the dimensions of granular surface features decreases. Furthermore, it is shown that electrodes based on annealed PtC material show an improved heterogeneous electron transfer rate for the oxidation of potassium hexacyanoferrate(II) trihydrate by almost three orders of magnitude, whereas the reduction of hexaammineruthenium(III) trichloride proceeds at similar rates for both treated and untreated electrodes. The rate of electrochemical oxidation of H₂O₂, which is influenced by the composition of the electrode surface, is also improved at thermally annealed electrodes. Finally, cyclic voltammetry in sulfuric acid shows an increase in surficial platinum concentration after annealing of the material.     

Novel Resonant Accelerometer with Micro Leverage Fabricated by MEMS Technology

For the purpose of improving the precision of the inertial guidance system,it is necessary to enhance the accuracy of the accelerometer.Combining the micro-fabrication processes with resonant sensor technology,a high-resolution inertial-grade novel micro resonant accelerometer is studied.Based on the detecting theory of the resonant sensors,the accelerometer is designed,fabricated,and tested.The accelerometer consists of one proofmass,two micro leverages and two double-ended-tuning-fork (DETF) resonators.The sensing principle of this accelerometer is based on that the natural frequency of the DETF resonator shifts with its axial load which is caused by inertial force.The push-pull configuration of the DETF is for temperature compensation.The two-stage micro leverage mechanisms are employed to amplify the force and increase the sensitivity of the accelerometer.The micro leverage and the resonator are modeled for static analysis and nonlinear modal analysis via theory method and finite element method (FEM),respectively.The geometrical parameters of them are optimized.The amplification factor of the leverage is 102,and the sensitivity of the resonator on theory is about 62 Hz/g.The samples of the accelerometer are fabricated with deep reactive ion etching (DRIE) technology which can get a high-aspect ratio structure for contributing a greater sensing-capacitance.The measuring results of the samples by scanning electron microscopy (SEM) show that the process is feasible,because of the complete structure,the sound combs and micro leverages,and the acceptable errors.The frequency of the resonator and the sensitivity of the accelerometer are tested via printed circuit board (PCB),respectively.The result of the test shows that the frequency of the push-resonator is about 54 530 Hz and the sensitivity of the accelerometer is about 55 Hz/g.The amplification factor of the leverage is calculated more accurately because the coupling of the two stages leverage is considered during derivation of the analysis formula.In addition,the novel differential structure of the accelerometer can greatly improve the sensitivity of the accelerometers.     

血管内支架的激光精细切割技术

激光精细切割是血管内支架的主要加工手段,它集中体现了激光加工的优越性,但激光切割产生微小的不精确性及热影响区会降低材料的生物相容性,影响血管内支架的应用.本文介绍了血管内支架的激光切割技术及其发展,着重分析了激光切割工艺对支架质量的影响.     

折叠波导慢波结构太赫兹真空器件研究

简要介绍了利用折叠波导慢波结构的太赫兹真空辐射源的发展现状,重点对折叠波导慢波结构的特点进行了研究,并利用这种慢波结构开展了W、D波段行波管,W波段和650GHz返波振荡器,560GHz反馈振荡放大器的设计、计算和模拟优化,分别得到了较好的结果,并实际研制出W波段连续波行波管,输出功率达到8W。对太赫兹真空辐射源的部件技术、微细加工技术进行了研究和分析。     

Electrical oscillation generation with current-induced resistivity switching in VO2 micro-channel devices

We report large amplitude modulation waveforms as large as ~ 10 V using vanadium dioxide micro-channel devices operating under current-controlled conditions. The self-sustained electrical oscillations were generated by controlling the applied current in the negative differential resistance region of the investigated devices. An appropriate value of internal capacitance was achieved as parasitic capacitance in the device structure to stabilize the electrical oscillations. This eliminates the need of an external pulsed source or any external passive component connected to the micro-channel devices. Amplitude and frequency of the oscillation were tuned by illuminating the device micro-channel with an external laser. An equivalent circuit model was developed to simulate the waveforms. A good agreement between experiment and simulation was verified.     

微机电系统科学与技术的现状研究

概述性地介绍了微机电系统(MicroElectroMechanicalSystem——MEMS)的定义及其特点。从理论基础、技术基础和应用研究三方面阐述了MEMS的主要研究内容。简要介绍了MEMS的基本加工技术，实际应用情况以及国内外MEMS的研究发展现状。     

微技术的研究现状与发展趋势

阐述了微技术的研究内容，现状及发展趋势。