一种经济型端齿盘数控回转台

通过对机床回转台种类的介绍,提出了一种既易于加工,成本又低的经济型数控回转台,并进行了设计计算。     

超声波键合能量引导微结构PMMA基片的制作

为了用超声波键合的方法实现微流控芯片的封装,采用选择性键合方式在聚甲基丙烯酸甲酯(PMMA)基片的微沟道两侧设计、制作了能量引导微结构,用热压法在同一PMMA基片上一次成形了凸起的能量引导微结构和凹陷的微沟道。用套刻和湿法腐蚀的方法制作了复合一体化硅模具。通过正交实验,确定了优化后的热压工艺参数。实验结果表明,由于同时存在凹、凸微结构,因此优化后的热压成形温度比传统的热压凹陷结构的成形温度提高15~20 ℃,在温度为140 ℃、保压时间为300 s、压力为1.65 MPa的实验条件下,微结构的复制精度达到了99％。     

压电超声微马达的研究新进展

介绍了国内外压电超声微马达的最新研究成果.总结出压电超声马达微型化的通用方法,并指出了压电超声微马达的下一步研究重点.     

Novel micro deep drilling using micro long flat drill with ultrasonic vibration

This paper highlights the development of micro long flat drills with nominal diameter and flute length of 20 μm and 200 μm, respectively, by precision grinding. Furthermore, it also covers the evaluation of the developed micro long flat drill in micro deep drilling. Micro long flat drills were made of ultra-fine grained cemented carbide containing WC particles with an average particle diameter of 90 nm. First, the study focused on establishing the optimal web thickness of micro long flat drill showing the best performance in micro deep drilling. In drilling experiment, observation was conducted with the aim of finding the best conditions and method of micro deep drilling into both duralumin and stainless steel workpieces. This observation included the applications of ultrasonic vibration (USV) and step feeding method. The study proved that there was an optimum web thickness resulting in the best drilling performance. Furthermore, the application of USV during drilling could lead to a longer tool life significantly. However, there was no improvement of drilling performance in drilling with step feeding.     

用于精密定位平台的直线超声电机的异步并联

提出了直线超声电机异步并联的概念以提高精密定位平台驱动单元的位移分辨率、输出力及速度.基本原理是若干定子(或振子)在一个振动周期内交替驱动动子(或转子),使实际的驱动频率成倍提高,可以获得更好的输出性能.分析显示,提高定子与动子之间的接触频率可以提高输出力和速度,改善瞬态响应特性,并可避免同步并联方式下定子的相互干扰问...     

超声滚压加工表面微织构的研究

为了研究超声滚压加工表面微织构工艺,选用45钢试样作为研究对象,分析了工艺参数包括滚压球直径、步距、静压力和进给速度对织构形貌及深度的影响,并对织构化后工件的表面性能进行了单因素实验.结果 表明,超声滚压工艺可以在表面制备稳定的织构,滚压球直径与步距对表面形貌影响较大,采用8 mm滚压球与0.2 m步距参数,能获得较为...     

超声振动微孔钻削轴向力研究

超声振动微孔钻削技术可在硬脆材料上加工出大长径比的微孔,因而越来越受到工业重视。根据动态切削厚度建立轴向力计算模型,使用MATLAB软件模拟得到微细钻头切削轨迹和动态切削厚度,结合已建立的三维钻削模型计算钻削过程中刀具受到的轴向力和转矩,并使用有限元软件Advant Edge来进行切削模拟,得出微细钻头受轴向力情况。可以得出,计算结果和模拟结果中轴向力变化趋势相同。     

Nonlinear ultrasonic techniques for nondestructive assessment of micro damage in material: A review

The nondestructive assessment of the damage that occurs in components during service plays a key role for condition monitoring and residual life estimation of in-service components/structures. Ultrasound has been widely utilized for this; however most of these conventional methods using ultrasonic characteristics in the linear elastic region are only sensitive to gross defects but much less sensitive to micro-damage. Recently, the nonlinear ultrasonic technique, which uses nonlinear ultrasonic behavior such as higher-harmonic generation, subharmonic generation, nonlinear resonance, or mixed frequency response, has been studied as a positive method for overcoming this limitation. In this paper, overall progress in this technique is reviewed with the brief introduction of basic principle in the application of each nonlinear ultrasonic phenomenon.     

An ESN-STM spectrometer for single spin detection

We have designed and built an ESN-STM spectrometer dedicated to single electron spin detection. Our spectrometer couples a home-made STM with a Real-Time Spectrum Analyzer. The head of the spectrometer allows routine imaging of molecules deposited on surfaces with high tunnelling current set point. In order to provide a maximal ESN-STM signal power transfer from the source (i.e. tunnelling junction) to the amplifier stage we have developed an impedance matching circuit between the tunnelling junction and impedance of RF signal amplifier. Our impedance matching circuit is based on application of a wide-spectrum amplifier equipped with FET transistor. In order to validate the usefulness of our ESN-STM spectrometer tests of sensitivity are presented. The main advantage of our spectrometer is the fact that it allows the collection of spin spectra from every single point of the topography image.     

OLED微显示器的原子扫描策略

为了实现2K及以上超高清微型显示器的高效率高性能扫描,建立了微型显示器的原子扫描模型。对该模型采用的数学矩阵、基于分形延伸的植入运算进行研究,提出了原子扫描策略并推导了原子扫描序列。首先,对现有的PWM(脉冲宽度调制)扫描策略进行扫描性能分析。然后,在分析比较几种扫描策略性能的基础上,说明原子扫描是实现较优性能的最佳选择。实验结果表明:对于256级灰度,采用32位子空间,8位权值比为128∶64∶32∶16∶9∶4∶2∶1的原子扫描策略具有较好的线性度和较高的传输效率。在分辨率为1 600×1 600的原子扫描方案中,时钟频率为50MHz,帧频可达90Hz,线性度接近99.8%,传输效率高达100%,基本满足超高分辨率扫描系统中高帧频、较低时钟、高线性度的要求。     

Nano force sensing using symmetric double stage micro resonator

A new approach is proposed to improve a graphical approach with considering intensity coupling loss coefficients in the analytical derivation of the optical transfer functions for a symmetric double stage vertically coupled microring resonator. An optimum transmission coupling condition is determined with considering terms of couplers intensity loss which leads to low insertion loss of 1.2 dB, finesse of 1525, the out of band rejection ratio of 61.8 dB. The resonating system is used as an optical force sensing system to make the benefit of the accuracy of measurements in micro and nano scales. The sensitivity of proposed force sensor in terms of wavelength-shift is 33 nm/nN and the limit of detection is 1.6 × 10⁻² nN. The proposed sensing system has the advantages of self-calibration and the low power consumption due to the low intensity.     

计算机控制的棒材在线自动超声波检测系统

介绍计算机控制的棒材在线自动超声波检测系统的技术性能、组成及特点等情况。     

A programmed controlled temperature microscope stage

The construction, and testing, of a programmed controlled temperature stage for optical microscopy is described. The stage is shown to be capable of attaining temperatures between 160 K and 373 K, and of providing repeatable heating and cooling rates up to, and in excess of 100 K min^?1. It is also capable of providing stable temperature holds.     

An automated system for ultrasonic testing of disks

The design and functions of separate units of an automated system for ultrasonic testing of disks in aircraft industry are briefly described. The testing results are presented in the form of a defectogram     

VREM: An advanced virtual environment for micro assembly

Micro assembly involves the assembly of micron-sized devices. Given the complexity of this domain, the role of virtual environments becomes important as they provide a basis to propose and compare assembly alternatives virtually prior to physical assembly. This paper proposes an integrated approach which includes the use of virtual reality-based assembly environments that interface with physical micro assembly environments. Such an approach can be an intrinsic part of a collaborative manufacturing framework that seeks to support the rapid assembly of micro devices. In this paper, the design of VREM (Virtual Reality based Environment for Micro Assembly) is discussed which is based on this integrated approach involving use of virtual and physical resources.     

微磨料汽雾超声抛光加工技术及实验研究

提出了一种新型精密抛光加工方法,即用含有微磨料的抛光液经超声振动使之雾化形成汽雾流,用此含有微磨料的汽雾流冲蚀工件表面而去除工件材料。通过产生汽雾流的超声振动分析和实验对这一微磨料汽雾超声抛光加工技术进行了研究。结果表明:这一方法可以实现对工件表面的抛光处理,而且比传统的抛光加工方法具有加工冲蚀力更柔软、加工质量更好,并且没有喷嘴损耗等优点。     

计算机控制多个微型步进电动机的原理

在一种自动测量调整系统中有5个供调速用的微型步进电动机,每个电动机有7种状态。在任一时间内每个电动机必须取7种状态中的一种,因而共有16807种组合,在指定时间内5个电动机的状态取何种组合,取决于测量系统所测到的数据,测量系统的数据由计算机进行采集、分析处理以确定各个电动机当时应选择的状态,然后由计算机控制使各电动机按要求的状态运作,各个电动机不同状态的运作,将改变所测到的数据。数据的改变又将反馈使电动机状态的改变,直至最后将参数调整致规定的范围内。文章介绍了计算机接口和步进电动机运转的控制线路及有关软件核心编程的要点。     

Piezo微步进工作台主框架研究

为了扩大微动工作台的有效行程,提出一种新型的基于Piezo驱动的微步进X-Y工作台,通过机构仿真确定了微步进工作台主框架中各柔性铰链的转角参数,并据此确定了主框架中各柔性铰链的结构参数,最后通过非线性有限元对整个微步进工作台主框架的变形情况进行了分析.