Manufacturing Metrology

Metrology is the science of measurement, which can be divided into three overlapping activities: (1) the definition of units of measurement, (2) the realization of units of measurement, and (3) the traceability of measurement units. Manufacturing metrology originally implicates the measurement of components and inputs for a manufacturing process to assure they are within specification requirements. It can also be extended to indicate the performance measurement of manufacturing equipment. This Special Issue covers papers revealing novel measurement methodologies and instrumentations for manufacturing metrology from the conventional industry to the frontier of the advanced hi-tech industry. Twenty-five papers are included in this Special Issue. These published papers can be categorized into four main groups, as follows: Length measurement: covering new designs, from micro/nanogap measurement with laser triangulation sensors and laser interferometers to very-long-distance, newly developed mode-locked femtosecond lasers. Surface profile and form measurements: covering technologies with new confocal sensors and imagine sensors: in situ and on-machine measurements. Angle measurements: these include a new 2D precision level design, a review of angle measurement with mode-locked femtosecond lasers, and multi-axis machine tool squareness measurement. Other laboratory systems: these include a water cooling temperature control system and a computer-aided inspection framework for CMM performance evaluation

Confocal laser scanning microscopy of nanoparticles applied to immunosorbent assays

The aim of this project was to demonstrate and develop a confocal readout method for fluorescent immunosorbent assays and investigate its potential advantages in comparison to traditional immunoassays. The key point of a confocal immunosorbent assay is the ability to detect the thin layer of immunoassay in the presence of unbound fluorescent reagents without washing the overlayer. Heterogeneous and homogeneous sandwich immunoassays of human IgG model were demonstrated successfully followed by the use of an empirical decomposition method for quantitative separation of the signals of the thin fluorescent assay layer from the overlayer. The detection limits for the homogeneous and heterogeneous formats of the model were 2.2 and 5.5 ng/ml, respectively. The application of confocal microscopy in kinetic analysis of the antigen-antibody reaction of the human IgG model was studied for homogeneous and heterogeneous formats and two fluorescent labels antibodies (FITC and QDs)

Optical Triangulation-Based Microtopographic Inspection of Surfaces

The non-invasive inspection of surfaces is a major issue in a wide variety of industries and research laboratories. The vast and increasing range of surface types, tolerance requirements and measurement constraints demanded during the last decades represents a major research effort in the development of new methods, systems and metrological strategies. The discreet dimensional evaluation the rugometric characterization and the profilometric inspection seem to be insufficient in many instances. The full microtopographic inspection has became a common requirement. Among the different systems developed, optical methods have the most important role and among those triangulation-based ones have gained a major status thanks to their flexibility, reliability and robustness. In this communication we will provide a brief historical review on the development of optical triangulation application to the dimensional inspection of objects and surfaces and on the work done at the Microtopography Laboratory of the Physics Department of the University of Minho, Portugal, in the development of methods and systems of optical triangulation-based microtopographic inspection of surfaces

Multiple View 3D Reconstruction of Micro- to Nano-Scopic Specimens

Range images and 3D modeling are often utilized on large scale specimens, but have been somewhat overlooked on the microscopic scale. This thesis concentrates on overcoming some of the difficulties of capturing images and creating both 3D models and 2D range images on this scale. During the scope of this thesis we take a deeper look into the optical mechanics of the laser scanning confocal microscope (LSCM) and scanning electron microscope (SEM) to understand the formation of the images and use that information to create our algorithms. With the use of the LSCM we can obtain a stack of 2D images of microscopic specimens. Our algorithm is able to process that stack of images and obtain both a 2D range image and a 3D model of a specimen from a single view. Through the use of computational methods and a set of eucentrically tilted images from the SEM we are able to obtain a surface point cloud of the specimen being modeled. By rotating the specimen and imaging it from several different angles a complete 3D model can be obtained. Through the implementation of our LSCM algorithm we have been able to obtain highly complete 3D reconstructions of both industrial and biological specimens of multiple size and shapes. The LSCM results produced and illustrated in this thesis exceed that of the current software available for producing both range images and 3D models. The results obtained from the SEM algorithm are a bit more modest yet offer an important understanding of the 3D characteristics of the specimens modeled. The point clouds produced and illustrated in this thesis show the accurate reconstruction of multiple points in a 3D space and when coupled with the 2D images produced by the SEM can help offer better depth understanding and measurement of features located on the specimen. Through the course of this thesis we have solved a few of the problems associated with 3D modeling on the microscopic level and offered a very good starting point from which to build upon. These reconstruction methods can be utilized individually or together for the use of better understanding and mapping microscopic organisms, reverse engineering, and quality control checks of microscopic parts

Integrated polymer photonics : fabrication, design, characterization and applications

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Computational image analysis of guided acoustic waves enables rheological assessment of sub-nanoliter volumes

We present a method for the computational image analysis of high frequency guided sound waves based upon the measurement of optical interference fringes, produced at the air interface of a thin film of liquid. These acoustic actuations induce affine deformations in the liquid, creating a lensing effect that can be readily observed using a simple imaging system. We exploit this effect to measure and analyze the spatio-temporal behavior as the acoustic wave interacts with the liquid. We also show that, by measuring the dynamics of the relaxation processes of these deformations when actuation ceases, we are able to determine the liquid's viscosity using just a lens-free optical sensor and a simple disposable biochip. Contrary to all other acoustic-based techniques in rheology, our measurements do not require monitoring of the wave parameters to obtain quantitative values for fluid viscosities, for sample volumes as low as 200 pL. We envisage that the proposed methods could enable high throughput, chip-based, reagent-free rheological studies within very small samples

Wavefront image sensor chip

We report the implementation of an image sensor chip, termed wavefront image sensor chip (WIS), that can measure both intensity/amplitude and phase front variations of a light wave separately and quantitatively. By monitoring the tightly confined transmitted light spots through a circular aperture grid in a high Fresnel number regime, we can measure both intensity and phase front variations with a high sampling density (11 µm) and high sensitivity (the sensitivity of normalized phase gradient measurement is 0.1 mrad under the typical working condition). By using WIS in a standard microscope, we can collect both bright-field (transmitted light intensity) and normalized phase gradient images. Our experiments further demonstrate that the normalized phase gradient images of polystyrene microspheres, unstained and stained starfish embryos, and strongly birefringent potato starch granules are improved versions of their corresponding differential interference contrast (DIC) microscope images in that they are artifact-free and quantitative. Besides phase microscopy, WIS can benefit machine recognition, object ranging, and texture assessment for a variety of applications

Assembly and proving of a wave front sensing confocal Scanning Laser Ophthalmoscope

Confocal Scanning Laser Ophthalmoscopy is used to image the fundus of the living eye. In theory, this technique can be used to observe single cells of the retina. Unfortunately, vision of most eyes is decreased by higher-order aberrations, that cannot be corrected by glasses or contact lenses. This is also the reason why resolution in confocal Scanning Laser Ophthalmoscopy is not as high as expected. By the use of adaptive optics (AO) resolution can be dramatically increased. Implementing a wave front sensor into a conventional confocal Scanning Laser Ophthalmoscope (cSLO), therefore, is the first step to set up a compact adaptive-optical cSLO. In this work a Shack-Hartmann wave front sensor was implemented into a slightly modified Heidelberg Retina Tomograph (HRT) and aberrations of model eyes were measured. Results show that this system is now ready for testing on living eyes

Measurement of the thickness of transparent coatings by interferometry

Робота публікується згідно наказу ректора від 29.12.2020 р. №580/од "Про розміщення кваліфікаційних робіт вищої освіти в репозиторії НАУ". Керівник проекту: доцент, к.т.н. Закієв Вадим ІсламовичThe diploma work considers elements of a system for application of transparent coating and its thickness measurement using white light interformetry. Subject of study – measurement of the thickness of transparent coating by interferpmetry. Aim of master thesis – is to develop a new non-destructive methods which can be used in the measurement of the thickness of a transparent coating. Novelty of the results ‒ it is the first time a new method of a non-destructive method is used in the measurements of the thickness of transparent coating which is base on the white light interformetry. Practical value ‒ its is the improvement in the methods used in measuring the thickness of transparent coating and without causing any form of structural or plastic deformation to the specimen used on, which is one of a very important aspect we consider in aviation run down to non-destructive methods of measuring the thickness by the used of white light interformetry. Also protecting and enhancing the aircraft in its performance and longer service life. Therefore the result of this work can be implemented in air and space industries by the adaptation of a more protective and improve air and space crafts