Photomicrography as an artistic medium

This thesis investigated the problems associated with artistically photographing patterns that exist within the microscopic world echoed on a larger scale throughout nature. Photographing these patterns at a microscopic level presented a number of difficulties not associated with photographing patterns through traditional photographic means. This thesis explored the problems associated with photographing subjects on a microscopic level, specifically the issues presented by lighting subjects. Experimental techniques with multiple light sources as well as light spectrum were explored. Also explored was the history of microscopy and popular processes for modern microscopy. Images were created utilizing either a compound microscope or stereomicroscope in conjunction with a digital single-lens reflex (SLR) camera and a microscopy lens attachment. Subjects for images consisted of a variety of live and dead coral specimen, algae, saliva, blood, marine vertebrates and invertebrates, and terrestrial insects. Recommendations for further studies of the microscopic world and patterns are also presented

An Eye for the Invisible: Exploring the Role of Image-Making in Science

This thesis tracks the evolution of filmed and photographed depictions of science, emphasizing in particular their dual existence as empirical research tools and stunning works of art

National Educators' Workshop: Update 1991. Standard Experiments in Engineering Materials Science and Technology

Given here is a collection of experiments presented and demonstrated at the National Educators' Workshop: Update 91, held at the Oak Ridge National Laboratory on November 12-14, 1991. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community

Microrobots for wafer scale microfactory: design fabrication integration and control.

Future assembly technologies will involve higher automation levels, in order to satisfy increased micro scale or nano scale precision requirements. Traditionally, assembly using a top-down robotic approach has been well-studied and applied to micro-electronics and MEMS industries, but less so in nanotechnology. With the bloom of nanotechnology ever since the 1990s, newly designed products with new materials, coatings and nanoparticles are gradually entering everyone’s life, while the industry has grown into a billion-dollar volume worldwide. Traditionally, nanotechnology products are assembled using bottom-up methods, such as self-assembly, rather than with top-down robotic assembly. This is due to considerations of volume handling of large quantities of components, and the high cost associated to top-down manipulation with the required precision. However, the bottom-up manufacturing methods have certain limitations, such as components need to have pre-define shapes and surface coatings, and the number of assembly components is limited to very few. For example, in the case of self-assembly of nano-cubes with origami design, post-assembly manipulation of cubes in large quantities and cost-efficiency is still challenging. In this thesis, we envision a new paradigm for nano scale assembly, realized with the help of a wafer-scale microfactory containing large numbers of MEMS microrobots. These robots will work together to enhance the throughput of the factory, while their cost will be reduced when compared to conventional nano positioners. To fulfill the microfactory vision, numerous challenges related to design, power, control and nanoscale task completion by these microrobots must be overcome. In this work, we study three types of microrobots for the microfactory: a world’s first laser-driven micrometer-size locomotor called ChevBot，a stationary millimeter-size robotic arm, called Solid Articulated Four Axes Microrobot (sAFAM), and a light-powered centimeter-size crawler microrobot called SolarPede. The ChevBot can perform autonomous navigation and positioning on a dry surface with the guidance of a laser beam. The sAFAM has been designed to perform nano positioning in four degrees of freedom, and nanoscale tasks such as indentation, and manipulation. And the SolarPede serves as a mobile workspace or transporter in the microfactory environment

3D SEM Surface Reconstruction: An Optimized, Adaptive, and Intelligent Approach

Structural analysis of microscopic objects is a longstanding topic in several scientific disciplines, including biological, mechanical, and material sciences. The scanning electron microscope (SEM), as a promising imaging equipment has been around to determine the surface properties (e.g., compositions or geometries) of specimens by achieving increased magnification, contrast, and resolution greater than one nanometer. Whereas SEM micrographs still remain two-dimensional (2D), many research and educational questions truly require knowledge and information about their three-dimensional (3D) surface structures. Having 3D surfaces from SEM images would provide true anatomic shapes of micro samples which would allow for quantitative measurements and informative visualization of the systems being investigated. In this research project, we novel design and develop an optimized, adaptive, and intelligent multi-view approach named 3DSEM++ for 3D surface reconstruction of SEM images, making a 3D SEM dataset publicly and freely available to the research community. The work is expected to stimulate more interest and draw attention from the computer vision and multimedia communities to the fast-growing SEM application area

Dielectrophoretic (DEP) Tweezers: New Tool for Molecular Force Spectroscopy

Many recent advances in DNA sequencing technology have taken advantage of single-molecule techniques using fluorescently-labeled oligonucleotides as the principle mode of detection. In spite of the successes of fluorescent-based sequencers, avoidance of labeled nucleotides could substantially reduce the costs of sequencing. This dissertation will describe the development of an alternative sequencing method, in which unlabeled DNA can be manipulated directly on a massively parallel scale using single molecule force spectroscopy. We demonstrated that a combination of a wide-field optical detection technique (evanescent field excitation) with dielectrophoretic (DEP) tweezers could determine the amount of the double-stranded character of DNA. This thesis discusses all aspects of the implementation of DEP tweezers, including the principle of operation, making of polymer force probes, numerical modeling of various designs, fabrication of electrode and disposable chip, force calibration, and the assembly of the device. The feasibility of this technique was demonstrated by conducting force spectroscopy on single DNA molecules using DEP tweezers. The development of such a single molecule force spectroscopy technique shows great potential for genome sequencing and other analytical applications that employ direct manipulation of biomolecules

Internalisation of biophotonic techniques : transfection, injection and thermometry

Single cell manipulation can offer great insights into the whole of an organism, the rapidly growing -omics fields are illustrating the heterogeneity that can be found within cell populations and where these subtle differences may be exploited, from fundamental knowledge to diagnostics and therapeutics. The cutting edge of this single cell work requires the application of interdisciplinary research to fully exploit the boundaries being pushed. Biophotonics is one such body of interdisciplinary research, employing light to manipulate biological samples. This work seeks to make use biophotonic techniques as analogues for conventional biological methods. High throughput raster scan photoporation is utilised for attempted transfection, multiple trap optical tweezers are used in an attempt to optically drive mechanical injection of cells and the thermal impact of these optical tweezers, which require high energy densities to confine particles, is tested, via the exploitation of the temperature sensitive emission of quantum dot nanoparticles

The relationship between the compressive strength of cement mortar and the chemical composition and fineness of cement

Includes bibliography.The purpose of this research was to determine a method whereby predictions of compressive strength could be made with regard to the chemical composition and fineness of Portland cement. Tests were performed on cement paste and mortar to determine which mixture would yield the most accurate, reproducible results. Paste was found to have a high degree of variation due to its mechanism of failure. Mortar, on the other hand, yielded reproducible and accurate results. In an attempt to prevent the high variations in the compressive strength of the paste, the paste was evacuated in a special evacuation chamber. The evacuation removed a large volume of air but did not alleviate the variations in the paste strength

BCR signaling and dynamic micropatterns

B lymphocytes (B cells) are an important part of the adaptive immune system. Recognition of surface presented antigen, typically on antigen presenting cell (APC), by the B cell receptor (BCR) triggers BCR signaling cascades leading to recruitment of the cytoskeleton and formation of a specialized cell-cell interaction structure, the immunological synapse (IS) on the interface of the APC and B cell. BCR activation ultimately leads to B cell differentiation into an antibody secreting plasma cell or a memory B cell. Studying the dynamic process of B cell activation presents a challenge, requiring spatial and temporal control over antigen presentation. Micropatterning of functional molecules allows control over cell placement. From many different micropatterning technologies, UV-lithography provides a cost-effective method for creating quality functional micropatterns on a glass substrate. In this work, I used poly-L-lysine-graft-polyethylene-glycol-biotin (PLL-g-PEG-biotin) coated glass coverslips with fibronectin patterning to control B cell attachment. In our dynamic micropatterns, temporal control of B cell activation is achieved via streptavidin- α IgM Fab acting as a surrogate antigen that binds the PLL-g-PEG-biotin outside the micropattern after cell attachment. Coverslips were imaged with spinning disk confocal or Airyscan confocal microscopy. Images of cells were segmented into separate regions of interest (ROI) and fluorescence intensities were measured inside these ROIs. This study shows that 1) functional coating of micropatterns was repeatable and highly specific, 2) spatial and temporal control of B cell activation was successful and 3) that enrichment of BCR signaling molecules Btk and PLCγ2 in the cell adhesion plane correlate with areas of antigen engagement

Mechanical Property Testing Apparatus for use in a Scanning Electron Microscope

The purpose of this design project is to develop a mechanical testing device to work in conjunction with a scanning electron microscope [SEM]. The objective of this work was to be able to perform a mechanical property measuring test and observe the small scale physical behavior of the sample with the SEM as the test progresses. The design process is presented from concept development through to the completion of the prototype device. Test data was acquired and analyzed and the results are compared to standard values for the materials being tested. Recommendations for future improvements in the next generation of the device are provided