48,030 research outputs found

    DEVELOPMENT OF A VERSATILE HIGH SPEED NANOMETER LEVEL SCANNING MULTI-PROBE MICROSCOPE

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    The motivation for development of a multi-probe scanning microscope, presented in this dissertation, is to provide a versatile measurement tool mainly targeted for biological studies, especially on the mechanical and structural properties of an intracellular system. This instrument provides a real-time, three-dimensional (3D) scanning capability. It is capable of operating on feedback from multiple probes, and has an interface for confocal photo-detection of fluorescence-based and single molecule imaging sensitivity. The instrument platform is called a Scanning Multi-Probe Microscope (SMPM) and enables 45 microm by 45 microm by 10 microm navigation of specimen with simultaneous optical and mechanical probing with each probe location being adjustable for collocation or for probing with known probe separations. The 3D positioning stage where the specimen locates was designed to have nanometer resolution and repeatability at 10 Hz scan speed with either open loop or closed loop operating modes. The fine motion of the stage is comprises three orthogonal flexures driven by piezoelectric actuators via a lever linkage. The flexures design is able to scan in larger range especially in z axis and serial connection of the stages helps to minimize the coupling between x, y and z axes. Closed-loop control was realized by the capacitance gauges attached to a rectangular block mounted to the underside of the fine stage upon which the specimen is mounted. The stage's performance was studied theoretically and verified by experimental test. In a step response test and using a simple proportional and integral (PI) controller, standard deviations of 1.9 nm 1.8 nm and 0.41 nm in the x, y and z axes were observed after settling times of 5 ms and 20 ms for the x and y axes. Scanning and imaging of biological specimen and artifact grating are presented to demonstrate the system operation. For faster, short range scanning, novel ultra-fast fiber scanning system was integrated into the xyz fine stage to achieve a super precision dual scanning system. The initial design enables nanometer positioning resolution and runs at 100 Hz scan speed. Both scanning systems are capable of characterization using dimensional metrology tools. Additionally, because the high-bandwidth, ultra-fast scanning system operates through a novel optical attenuating lever, it is physically separate from the longer range scanner and thereby does not introduce additional positioning noise. The dual scanner provides a fine scanning mechanism at relatively low speed and large imaging area using the xyz stage, and focus on a smaller area of interested in a high speed by the ultra-fast scanner easily. Such functionality is beneficial for researchers to study intracellular dynamic motion which requires high speed imaging. Finally, two high end displacement sensor systems, a knife edge sensor and fiber interferometer, were demonstrated as sensing solutions for potential feedback tools to boost the precision and resolution performance of the SMPM

    inTrack: High Precision Tracking of Mobile Sensor Nodes

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    Radio-interferometric ranging is a novel technique that allows for fine-grained node localization in networks of inexpensive COTS nodes. In this paper, we show that the approach can also be applied to precision tracking of mobile sensor nodes. We introduce inTrack, a cooperative tracking system based on radio-interferometry that features high accuracy, long range and low-power operation. The system utilizes a set of nodes placed at known locations to track a mobile sensor. We analyze how target speed and measurement errors affect the accuracy of the computed locations. To demonstrate the feasibility of our approach, we describe our prototype implementation using Berkeley motes. We evaluate the system using data from both simulations and field tests

    Characteristics and capacities of the NASA Lewis Research Center high precision 6.7- by 6.7-m planar near-field scanner

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    A very precise 6.7- by 6.7-m planar near-field scanner has recently become operational at the NASA Lewis Research Center. The scanner acquires amplitude and phase data at discrete points over a vertical rectangular grid. During the design phase for this scanner, special emphasis was given to the dimensional stability of the structures and the ease of adjustment of the rails that determine the accuracy of the scan plane. A laser measurement system is used for rail alignment and probe positioning. This has resulted in very repeatable horizontal and vertical motion of the probe cart and hence precise positioning in the plane described by the probe tip. The resulting accuracy will support near-field measurements at 60 GHz without corrections. Subsystem design including laser, electronic and mechanical and their performance is described. Summary data are presented on the scan plane flatness and environmental temperature stability. Representative near-field data and calculated far-field test results are presented. Prospective scanner improvements to increase test capability are also discussed

    Micro-manufacturing : research, technology outcomes and development issues

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    Besides continuing effort in developing MEMS-based manufacturing techniques, latest effort in Micro-manufacturing is also in Non-MEMS-based manufacturing. Research and technological development (RTD) in this field is encouraged by the increased demand on micro-components as well as promised development in the scaling down of the traditional macro-manufacturing processes for micro-length-scale manufacturing. This paper highlights some EU funded research activities in micro/nano-manufacturing, and gives examples of the latest development in micro-manufacturing methods/techniques, process chains, hybrid-processes, manufacturing equipment and supporting technologies/device, etc., which is followed by a summary of the achievements of the EU MASMICRO project. Finally, concluding remarks are given, which raise several issues concerning further development in micro-manufacturing

    RFID Localisation For Internet Of Things Smart Homes: A Survey

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    The Internet of Things (IoT) enables numerous business opportunities in fields as diverse as e-health, smart cities, smart homes, among many others. The IoT incorporates multiple long-range, short-range, and personal area wireless networks and technologies into the designs of IoT applications. Localisation in indoor positioning systems plays an important role in the IoT. Location Based IoT applications range from tracking objects and people in real-time, assets management, agriculture, assisted monitoring technologies for healthcare, and smart homes, to name a few. Radio Frequency based systems for indoor positioning such as Radio Frequency Identification (RFID) is a key enabler technology for the IoT due to its costeffective, high readability rates, automatic identification and, importantly, its energy efficiency characteristic. This paper reviews the state-of-the-art RFID technologies in IoT Smart Homes applications. It presents several comparable studies of RFID based projects in smart homes and discusses the applications, techniques, algorithms, and challenges of adopting RFID technologies in IoT smart home systems.Comment: 18 pages, 2 figures, 3 table

    Miniaturized modular manipulator design for high precision assembly and manipulation tasks

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    In this paper, design and control issues for the development of miniaturized manipulators which are aimed to be used in high precision assembly and manipulation tasks are presented. The developed manipulators are size adapted devices, miniaturized versions of conventional robots based on well-known kinematic structures. 3 degrees of freedom (DOF) delta robot and a 2 DOF pantograph mechanism enhanced with a rotational axis at the tip and a Z axis actuating the whole mechanism are given as examples of study. These parallel mechanisms are designed and developed to be used in modular assembly systems for the realization of high precision assembly and manipulation tasks. In that sense, modularity is addressed as an important design consideration. The design procedures are given in details in order to provide solutions for miniaturization and experimental results are given to show the achieved performances

    Interaction of marine geodesy, satellite technology and ocean physics

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    The possible applications of satellite technology in marine geodesy and geodetic related ocean physics were investigated. Four major problems were identified in the areas of geodesy and ocean physics: (1) geodetic positioning and control establishment; (2) sea surface topography and geoid determination; (3) geodetic applications to ocean physics; and (4) ground truth establishment. It was found that satellite technology can play a major role in their solution. For solution of the first problem, the use of satellite geodetic techniques, such as Doppler and C-band radar ranging, is demonstrated to fix the three-dimensional coordinates of marine geodetic control if multi-satellite passes are used. The second problem is shown to require the use of satellite altimetry, along with accurate knowledge of ocean-dynamics parameters such as sea state, ocean tides, and mean sea level. The use of both conventional and advanced satellite techniques appeared to be necessary to solve the third and fourth problems

    Performance and analysis of a three-dimensional nonorthogonal laser Doppler anemometer

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    A three dimensional laser Doppler anemometer with a nonorthogonal third axis coupled by 14 deg was designed and tested. A highly three dimensional flow field of a jet in a crossflow was surveyed to test the three dimensional capability of the instrument. Sample data are presented demonstrating the ability of the 3D LDA to resolve three orthogonal velocity components. Modifications to the optics, signal processing electronics, and data reduction methods are suggested
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