Micro devices assembly using virtual environments

In this paper, the design and development of a physical and virtual environment to support assembly of micron sized devices is discussed. Micro assembly involves handling and assembling of micron sized parts (10⁻⁶ m). As manual assembly of micron-sized parts is difficult and tedious, the design of computer assisted micro-assembly techniques becomes crucial. An Integrated Physical and Virtual Reality (VR) environment has been created to aid in the assembly of such micro devices, which supports the establishment of an interface between a virtual and physical micro assembly work cell. The overall architecture and the various modules implemented in this environment are outlined in this paper.     

Design and manufacturing of mobile micro manipulation system with a compliant piezoelectric actuator based micro gripper

This paper presents a new design of mobile micro manipulation system for robotic micro assembly where a compliant piezoelectric actuator based micro gripper is designed for handling the miniature parts and compensation of misalignment during peg-in-hole assembly is done because piezoelectric actuator has capability of producing the displacement in micron range and generates high force instantaneously. This adjusts the misalignment of peg during robotic micro assembly. The throughput/speed of mobile micro manipulation system is found for picking and placing the peg from one hole to next hole position. An analysis of piezoelectric actuator based micro gripper has been carried out where voltage is controlled through a proportional-derivative (PD) controller. By developing a prototype, it is demonstrated that compliant piezoelectric actuator based micro gripper is capable of handling the peg-in-hole assembly task in a mobile micro manipulation system.     

Electroosmotic pumps and their applications in microfluidic systems

Electroosmotic pumping is receiving increasing attention in recent years owing to the rapid development in micro total analytical systems. Compared with other micropumps, electroosmotic pumps (EOPs) offer a number of advantages such as creation of constant pulse-free flows and elimination of moving parts. The flow rates and pumping pressures of EOPs matches well with micro analysis systems. The common materials and fabrication technologies make it readily integrateable with lab-on-a-chip devices. This paper reviews the recent progress on EOP fabrications and applications in order to promote the awareness of EOPs to researchers interested in using micro- and nano-fluidic devices. The pros and cons of EOPs are also discussed, which helps these researchers in designing and constructing their micro platforms.     

A Visualization System for Analysis of Micro Aerial Vehicle Scaled Flapping Wings

This paper presents a visualization system for analysis of micro aerial vehicle (MAV) scaled flapping wings. By synchronizing to the wing under test, multiple devices can be triggered at precise phases in the flapping cycle with a high degree of accuracy and repeatability. The system can control devices such as strobe lights, lasers and cameras to capture wing motion and flow visualization data at the point of interest. The system was developed, then implemented and tested under ideal and real-world conditions to evaluate several aspects of performance. The effectiveness of the system was then demonstrated in a flow visualization experiment, where it was used to capture images of the average airflow around a flapping wing at several wing phases. Performance measurements showed the high accuracy of the system, while flow visualization results demonstrated significant improvements in the quality and accuracy of images when the system was used for analysis of a flapping wing. These results indicate the potential of the developed system to considerably improve visualization analysis of MAV scaled flapping wings.     

Development and application of miniaturized scanners for laser beam micro-welding

Nowadays, flexible production systems for laser joining of micro parts require high dynamics and precision, as well as increased flexibility regarding the working space. The combination of miniaturized scanner-based laser joining systems and high-performance assembly systems is a new approach for a high accuracy compact micro assembly system with an increased flexibility. Using highly dynamic oscillation techniques leads to a stabilization of the welding process of difficult-to-weld materials, e.g. of zinc-containing alloys on the one hand, and to an increased process velocity and reduction of the joining geometry, e.g. for the welding of plastic materials on the other. Hence, a miniaturized laser processing optics is being developed featuring an integrated beam deflection for laser beam micro welding of metal as well as plastic materials. The requirements on this laser processing optics, the choice of a suitable beam deflection system and the design and simulation of the miniaturized optics are presented and discussed. Furthermore, results of laser beam micro welding applications are presented. These results directly influence the design of new miniaturized laser processing optics. By means of the integration of highly dynamic scanner devices further process improvements can be achieved for laser beam micro welding.     

Gastric-fluid-utilizing micro battery for micro medical devices

A variety of micro medical devices have been developed to provide more advanced and less invasive medical treatment. An effective power supply is crucial to the operation of these devices. Currently, two types of power supply are used: small batteries or radio-power transmission. However, the former limits the operating time of the devices, while radio-power transmission affects other medical devices due to the electromagnetic waves. In this paper, we report on a gastric-fluid-utilizing micro battery (GMB) that utilizes the gastric fluid in the stomach as an electrolyte. The GMB is designed to be used in the stomach and to generate electricity based on the principle of the voltaic cell. It consists only of biocompatible materials, including the electrodes, porous ceramic filter, and polydimethylsiloxane casing. Platinum deposited on a thin glass plate and a zinc plate work as positive and negative electrodes, respectively. Though zinc dissolves during the generation of electricity, it is an essential trace metal for humans and, given the small amount released, is not toxic. The porous ceramic filter placed between the electrodes filters out any foreign materials in the stomach fluid and holds the gastric fluid by capillary attraction. In experiments, GMB successfully generated 1.0 mW (0.42 V, 2.41 mA) with a 200-Ω external load. It generated a stable output voltage of 0.6 V for more than 39 min with a 5-kΩ external load. We demonstrated the feasibility of the GMB for medical applications by successfully supplying power to a telemetric system and a tiny DC motor that is commercially available.     

Micro gas bearings fabricated by deep X-ray lithography

Micro bearing systems for Micro Electromechanical Systems (MEMS) have drawn attention for several decades as critical components for micro rotating machinery. Ideally, frictionless bearings are needed, and in practice, micro gas bearings approach the ideal. Typically, bearings function as a separate component, assembled onto sliding counterparts. However, in micro scale devices, assembly procedures are known to be very tedious and time consuming. This leads to the pursuit of single material monolithic structures. Critical issues arising from these approaches include: limitation of materials, friction, and reliability, among others. In this paper, new approaches have been pursued. Micro gas bearings were fabricated as a single component through X-ray lithography. A stainless steel gauge pin, machined to ultra precision, was used as a journal shaft. Simple and very easy assembly processes using self-aligning concepts were developed as an alternative method to conventional assembly. This article presents the design, fabrication, assembly, and testing of micro gas bearings.This project was funded from National Science Foundation (DMI-0115527) and Atoz CompuNet Ltd. The authors also acknowledge partial support from Center for Nano and Molecular Science and Technology and Welch foundation in The University of Texas at Austin.     

Micro assembly injection moulding

Injection moulding is established as one of the most common manufacturing processes of thermoplastics due to its high degree of automation and the short cycle times. Micro injection moulding is a rapidly growing technology that allows for the efficient production of very complex micro parts in high series. The “Market Analysis for Microsystems II 2002–2005” of the Nexus Task Force anticipates a yearly growth in the field of micro system technology of about 20% (Wechsung et al. 2002). This study identifies in addition to the continuous miniaturization the growing use of polymers in micro systems (Schneider et al. 2001). No other material group offers this wide range of material properties and permits to choose processing parameters and application properties according to necessities (Gächter 2000). While the production processes of micro technical components are mainly controllable, the assembly of these components to hybrid micro systems is a bottleneck to the industrial large scale production. The assembly itself represents a large fraction of the added product value and gains in importance with growing complexity and miniaturization of the systems.     

计算机应用基础微课程的研究

随着信息水平的不断提高,教学资源的网络化已成为教学改革的方向之一。目前对教学资源的设计及开发,尤其是多媒体视频资源的研究成为教学研究的重点。本文主要研究了如何科学、合理、高效的进行计算机应用基础微课程的设计与开发,使微课程能够激发学生学习兴趣,提高教学质量。     

Helical surface creation by wire electrical discharge machining for micro tools

In mechanical micromachining, micro tooling is one of the key factors affecting the finished geometrical accuracy and surface quality. To overcome the serious tool wear caused by relatively longer micromachining time, micro tools are usually made of ultra-hard materials such as polycrystalline diamond (PCD) or cubic boron nitride (CBN). Wire Electrical discharge machining (WEDM) is a good choice for efficient fabrications of micro tools made of ultra-hard materials. Considering the traces of wire motions form ruled surfaces, in this paper, typical custom micro milling tools with helical surfaces are generated by ruled surfaces. The simulation shows that the selection of guide lines and generating lines for ruled surface is the key point relating to the final geometrical accuracy and machining efficiency in custom micro tool fabrications by WEDM. Based on the mathematical models built in this paper, overcut can be avoided in the process planning stage for complicated helical surfaces. Furthermore, wire locations can be created conveniently by the introduced mathematical models for post processing in dedicated CAM systems.     

一种微小型无人机带死区变增益PID自适应控制器的设计与实现

针对一种常规布局的微小型无人机定点飞行任务中存在的传感器测量精度不高以及发动机振动引起的抖舵问题, 设计了带死区变增益 PID 自适应控制器. 文中给出了滚转、航向、俯仰以及位置反馈信号的融合算法, 有效地实现了对定姿稳定控制以及定高、定航点的轨迹跟踪控制, 并利用实验验证了纵向、滚转和航向三个通道的稳定性. 实验结果表明, 所设计的导航、控制系统能有效抑制不确定项的影响, 且可获得良好的动态跟踪性能.     

三基色原理在火工品温度场测试中的应用

随着微纳米结构含能药剂在火工品中的广泛应用,微尺度火工品逐渐朝着微型化方向发展。这对小尺寸条件下温度的测试提出了新的挑战。燃烧温度作为微尺度火工品输出性能的重要参数之一,对火工品输出能力评价具有重要意义。为了测量微尺度火工品燃烧温度场,根据三基色原理和普朗克定律建立三基色测温公式,搭建了一套由光学镜头、彩色相机、软件系统和计算机组成的测温系统。利用黑体炉对系统进行标定,建立温度与三基色值的关系,并对测量误差进行了分析与讨论。通过与红外热像仪测量结果对比,三基色测温法的准确性较高,两者测得的最高温度相差不超过1%,为微尺度火工品燃烧温度场的测量提供了思路。     

Development of a novel protective cover for micro manipulation process in the SEM chamber

This paper presents a novel approach to assembly of micro components in a scanning electron microscope (SEM) chamber. A new set, called Protective Cover for micro components allows their quick positioning on the platform inside the SEM chamber without gluing. It is well known that the vacuum pumps, especially turbo one, which evacuated a SEM chamber, are highly sensitive to foreign object damage. This is the reason why the micro components are glued on the specimen holder in the SEM chamber. On the other hand, the grippers that have to pick, lift and place the micro components in a desired system (position, orientation) are very fragile. They can not overcome the adhesive force of the glue and remove the particle from the specimen holder. The presented system is standardized and can be mounted without additional time, modification or expenses into the SEM chamber. It enables, on the one hand, easier manipulation of the micro components that do not need to be glued on the specimen holder and, on the other hand, introduces further automation in the manipulation process in the SEM chamber since it creates thus a necessary basis for modular assembling system. Furthermore, it is very important for the automated assembly process that the micro components are exactly positioned. The standardization in the micro world becomes more and more essential. The uniformity of parts, operations and tools strongly supports an automatic assembly system.     

Application of micro CT and computation modeling in bone tissue engineering

Computer aided technologies, medical imaging, and rapid prototyping has created new possibilities in biomedical engineering. The systematic variation of scaffold architecture as well as the mineralization inside a scaffold/bone construct can be studied using computer imaging technology and CAD/CAM and micro computed tomography (CT). In this paper, the potential of combining these technologies has been exploited in the study of scaffolds and osteochondral repair. Porosity, surface area per unit volume and the degree of interconnectivity were evaluated through imaging and computer aided manipulation of the scaffold scan data. For the osteochondral model, the spatial distribution and the degree of bone regeneration were evaluated. In this study the versatility of two softwares Mimics (Materialize), CTan and 3D realistic visualization (Skyscan) were assessed, too.     

Micro parts assembly system with micro gripper and RCC unit

This paper presents a new micro assembly system, which is composed of a micro gripper, a micro remote center compliance (RCC) unit, a voice coil motor-driving mechanism and precision motion stages. The micro gripper is actuated by two shape memory alloy (SMA) wires, and its grip is 1 mm. The micro RCC unit has low translational and rotational stiffness sufficient for micro parts assembly. The voice coil motor-driving mechanism can generate linear motion with an adjustable stiffness, and it can also measure external force in the moving direction. An algorithm for the automatic assembly of micro parts is also proposed, and assembly experiments are performed.     

国外微型管内机器人的发展

本文首先论述了微型管道机器人的发展背景及与传统管内机器人的区别,然后 对几种典型常规小管径管道机器人和国外几种典型微驱动式管内微型机器人工作原理对比分 析,指出了目前管内微型机器人研究中所面临的主要问题,并对实现微管内机器人 实用化的关键技术及研究发展方向进行了探讨．     

二氧化碳薄膜微电极器件的制作 及其特性研究

提出一种用微细加工技术构制的二氧化碳薄膜微电极器件。这类器件具有常规微电极所特有的全部优点，而且结构紧凑，便于集成化。用作电流型二氧化碳气敏器件，在室温下有良好的工作特性：响应电流在整个ＣＯ２浓度范围内呈线性，并通过原点；９０％响应时间约３０ｓ；连续工作６ｈ性能稳定，重现性好。     

Development of Multi Micro Manipulation System Using IPMC Micro Grippers

This paper presents a new design of multi micro manipulation system using ionic polymer metal composite (IPMC) micro grippers for robotic micro assembly where IPMC is used as a light weight actuator for developing the micro grippers. It has the potential of large displacement, low mass force generation and misalignment compensation ability during micro manipulation. These capabilities are utilized for handling of miniature parts like pegs. The analysis of IPMC micro gripper and manipulator are carried out for developing a multi micro manipulation system that can handle pegs in micro assembly operation for shifting one to another hole position in a large work space (100 mm × 100 mm). By developing a prototype, it is demonstrated that IPMC based micro grippers are capable of handling the peg-in-hole assembly tasks in a multi micro manipulation system.     

基于单片机的多并行接口设备数据传输的集成和控制

在要求传输距离近,通信速度快的数据采集应用中,如CCD、视频数据采集,往往采用并行接口方式。该文针对目前多并行接口设备数据传输方式中采用多计算机收集数据和采用并行接口数据采集卡存在的不足,提出了采用单片机对多台利用并行接口进行数据传输的设备进行集成和控制,完成数据的传输。在数据传输中,针对计算机的标准并行接口,及所有外围设备的数据线是共用,而控制线则需要独立地和计算机建立握手协议的特点,通过单片机接管外围设备的控制线,完成对多设备数据传输的集成和控制。该方法已经在近景三维测量系统中得到了应用,并取得了满意的结果。     

基于椭球拟合的微惯性测量组合现场快速标定方法

在静态随意放置条件下,微惯性测量组合中三个轴向正交配置的惯性器件所敏感矢量和为固定矢量.依据上述客观事实,提出了一种微惯性测量组合现场快速标定方法.在建立并优化微惯性测量组合标定模型基础上,通过基于椭球约束的最小二乘法拟合得到全部待标定参数,从而实现微惯性测量组合现场高精度标定,最后合理编排了微惯性测量组合现场快速标定...