Vortex flow generator utilizing synthetic jets by diaphragm vibration

This paper develops a millimeter scale fully packaged device in which a vortex flow of high velocity is generated inside a chamber. Under the actuation by a lead zirconate titanate (PZT) diaphragm, a flow circulates with increasing velocity after each actuating circle to form a vortex in a cavity named as the vortex chamber. At each cycle, the vibration of the PZT diaphragm creates a small net air flow through a rectifying nozzle, generates a synthetic jet which propagates by a gradual circulation toward the vortex chamber and then backward the feedback chamber. The design of such device is firstly conducted by a numerical analysis whose results are considered as the base of our experimental set-up. A vortex flow generated in the votex chamber was observed by a high-speed camera. The present approach which was illustrated by both the simulation and experiment is potential in various applications related to the inertial sensing, fluidic amplifier and micro/nano particle trapping and mixing

The Role of MEMS in In-Vitro-Fertilization

The assisted reproduction has been considered a viable solution for the infertility of humankind for more than four decades. In-Vitro-Fertilization (IVF) is one of the most successful assisted reproduction techniques, where the reproductive cell of the female partner is fertilized outside of her body. Initially, the IVF process has been conducted manually by an experienced embryologist. However, even with a highly experienced individual, the operation had extremely lower success rates due to the limited control in environmental conditions and the requirement of precise movements. Therefore, to address this technological deficit, the feasibility of the mechatronics devices for IVF procedures has been investigated. Among the different mechatronics concepts, micro-electromechanical system (MEMS) technologies have been gradually attracted to the IVF process and improved its capabilities. The purpose of this paper is to present a brief overview of the role of MEMS technologies in IVF. The article classifies the MEMS technologies in IVF based on their application in order to emphasize its contribution. In addition, the article extensively discusses the state-of-the-art mechatronic techniques utilized in Intracytoplasmic Sperm Injection (ICSI), one of the most popular techniques used in IVF. This review article expects to become extremely beneficial for the engineering researchers new to this field who seek critical information on IVF in simple terms with highlights on the possible advancements and challenges that may emerge in the future

A closed device to generate vortex flow using PZT

This paper reports for the first time a millimeter scale fully packaged device which generates a vortex flow of high velocity. The flow which is simply actuated by a PZT diaphragm circulates with a higher velocity after each actuating circle to form a vortex in a desired chamber. The design of such device is firstly conducted by a numerical analysis using OpenFOAM. Several numerical results are considered as the base of our experiment where a flow vortex is observed by a high speed camera. The present device is potential in various applications related to the inertial sensing, fluidic amplifier and micro/nano particle trapping and mixing

Industrial Robotics for Advanced Machining

This work presents a literature review of the current state of robotic machining with industrial machining robots, primarily those with 6-axis end effectors and serial link (anthropomorphic) construction. Various disadvantages of robotic machining in industry are presented, as well as the methods applied to mitigate them and discussions of their effects. From this review, the methods of dynamic modelling, stability prediction and configuration control are selected for application to the task of optimisation of a robotic machining cell for drilling operations. Matrix Structural Analysis (MSA) and methods developed by Klimchik et al. are used for compliance modelling, stability prediction methods developed by Altintas et al. and machining stability lobe prediction are then applied to a robotic drilling process, as explored by Mousavi et al. This optimisation method is applied using the measured and estimated properties of an ABB IRB 6640 robot and results are presented in comparison with previous experimentation with the physical robot, and analytical stability predictions from the same cutting parameters with Cutpro software. Results are discussed in the concluding chapters, as well as discontinued parts of the project and suggestions for future work

Aeronautical engineering, a continuing bibliography with indexes

This bibliography lists 419 reports, articles and other documents introduced into the NASA scientific and technical information system in March 1985

Harmonic resonances in nonlinear Josephson junction circuits : experimental and analytical studies

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (p. 191-196).by Amy Elizabeth Duwel.Ph.D

Aeronautical Engineering: A continuing bibliography

This bibliography lists 347 reports, articles and other documents introduced into the scientific and technical information system. Documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated compounds, equipment, and systems are included. Research and development in aerodynamics, aeronautics and ground support equipment for aeronautical vehicles are also included

Third International Symposium on Magnetic Suspension Technology

In order to examine the state of technology of all areas of magnetic suspension and to review recent developments in sensors, controls, superconducting magnet technology, and design/implementation practices, the Third International Symposium on Magnetic Suspension Technology was held at the Holiday Inn Capital Plaza in Tallahassee, Florida on 13-15 Dec. 1995. The symposium included 19 sessions in which a total of 55 papers were presented. The technical sessions covered the areas of bearings, superconductivity, vibration isolation, maglev, controls, space applications, general applications, bearing/actuator design, modeling, precision applications, electromagnetic launch and hypersonic maglev, applications of superconductivity, and sensors

Trapped between two beams – higher order laser mode manipulation for cell rotation

Laser light is an exceptionally powerful tool which has been utilised across all natural sciences and engineering. The very high intensities of extremely controllable light have allowed for a diverse range of studies to be carried out. When the intensities are large enough, the act of redirecting the light can create a force which can be sufficient to move small transparent objects. In biology one application of this phenomenon forms a tool for trapping and handling microscopic cellular samples in a contactless way using two laser beams. Such a laser-based tool is the Optical Stretcher, it was invented for measuring the mechanical properties of single cellular biological samples. The work presented in this thesis built upon the Optical Stretcher and to gain expertise in the field, several different biological samples were tested using it, gaining insights into the impact of particular proteins to cell mechanics. The Optical Stretcher, along with the vast majority of cell trapping experiments utilises a rotationally symmetric laser beam, which allows the cells to be moved and held in place, but their orientation is random and subject to large fluctuations. Controlled orientation of cellular specimen can lead to improved 3D imaging of the sample and is an important field of study. Previous work has shown that it is possible to orient a cell using a specially shaped laser beam, however the experimental setups were not well suited to use in biological labs. Henceforth, this thesis investigated and engineered a Dual Beam Laser Trapping device called the Higher Order Mode Cell Rotator, in short HOMCR, in order to build a powerful all-in-fibre tool for tomographic cell rotation. The major component giving rise to the HOMCR was a polarisation controlling device that alters the state of light by squeezing on the laser fibre and inducing local changes in the polarisation profile of the laser light. By characterising this device, its capability has been shown for the first time to manipulate the two lobe higher order modes travelling in optical fibres, leading to an all-in-fibre dynamic cell rotator which was used successfully to trap and orient individual cells and larger biological samples