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In this paper, we present the design, analysis, and testing of an ankle rehabilitation device (ARD), the purpose of which is to improve the efficacy of ankle joint complex (AJC) injury diagnosis and treatment. The ARD enables physicians to quantitatively measure the severity of an injury. This is done by measuring deficiencies in the joint's range of motion, as well as force, torque, and power output. Evaluation of the relative degree of recovery over time can also reduce the error associated with current methodologies for rehabilitation, which rely on measurements based on the patient's verbal response. A Wheatstone bridge circuit is used for the measurement of the various parameters as applied to the blades of complementary rotational flexures; the device is designed to measure motion about three axes of rotation in the ankle joint: pitch, roll, and yaw. A full bridge circuit is applied to each axis of rotation, and the use of multiple axes increases anatomically accurate measurement, enabling characterization of coupled motions. The device has flexibility and a range of motion such that it can be adjusted to take measurements of multiple different degrees of plantar or dorsiflexion of the AJC. The ARD is able to measure both range of motion, force, and torque output simultaneously. Experimental results show that there is significant coupled motion among the ankle joint rotations but that it is highly dependent on a subject's own physical development.

Recently, there has been an interest in designing systems that employ buckling bifurcation as a desired mechanism to generate motion and/or form. As buckling has traditionally been considered a failure mode to be avoided, computational tools for predicting the state of the system after buckling are not well developed. For example, modules for post-bifurcation studies are not available in most of the commercial finite element software packages. Herein, we provide MATLAB codes that add the ability to perform post-bifurcation studies to the commercially available COMSOL finite element package. This is achieved by implementing mesh perturbations as a scheme to introduce geometric imperfections to the system. Additionally, we provide codes to automate pre/post processing the studies. These codes enable performing (i) post-bifurcation analysis, (ii) studies on sensitivity to mesh imperfections, and (iii) unattended parametric studies that require re-meshing the geometry.

SUMMARY This paper presents the design of a monocular three dimensional artificial vision system attached to a 20x microscope lens for precision and microsystems applications. Possible uses in assembly include: positioner calibration, sensor-based part handling, positioning, and inspection in the nanometric range. The developed image acquisition method – along one direction (in steps of 100 nm), the depth-from-focus algorithm and subpixel interpolation (of 5 acquisitions for concurrent localization and inspection), allow to overcome the physical optics limitation achieving a resolution under 200 nm. The vision strategy and algorithms, described in the paper, have been validated by handling an AFM probe array by a micropositioner.

This international technology assessment study has focused on the emerging global trend toward the miniaturization of manufacturing processes, equipment and systems for microscale components and products, i.e., Small Equipment for Small Parts. It encompasses the creation of miniaturized units or hybrid processes integrated with metrology, material handling and assembly to create microfactories capable of producing microprecision products in a fully automated manner at low cost. The study has investigated both the state-of-the-art as well as emerging technologies from the scientific, technological, and commercialization perspectives across key industrial sectors in the U.S., Asia and Europe including medical, electronics, aerospace, and consumer products. This study does NOT include the lithographic-based processes common to the microelectromechanical systems (MEMS) community. While the U.S. gets high marks for nanotechnology R&D, emphasis in the U.S. on micromanufacturing R&D is lagging behind the rest of the world, particularly in technology transfer and ongoing development. This will undoubtedly have serious long-term implications, since it is well-recognized that micromanufacturing will be a critical enabling technology in bridging the gap between nanoscience and technology developments and their realization in useful products and processes. While examples do exist where U.S. government programs are focused squarely on industry-university-government collaboration, the scale of efforts both in Asia and Europe is significantly larger. On this latter point, Europe appears to be very strong, particularly as these partnerships work to refine and fine-tune developments for industry adaptation and commercialization., The original document contains color images. Sponsored in part by the National Science Foundation Grant no. ENG-0423742, the Department of Energy and the National Institute of Standards and Technology.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2000., Includes bibliographical references (p. 113-116)., Better precision at lower costs is a major force in design and manufacturing. However, this is becoming increasingly difficult to achieve as the demands of many location applications are surpassing the practical performance limit (~ five microns) of low-cost couplings. The absence of a means to meet these requirement has motivated the development of the Quasi-Kinematic Coupling (QKC). This thesis covers the theoretical and practical considerations needed to model and design QKCs. In a QKC, one component is equipped with three spherical protrusions while the other contains three corresponding conical grooves. Whereas Kinematic Couplings rely on six points of contact, the six arcs of contact between the mated protrusions and grooves of QKCs result in a weakly over-constrained coupling, thus the name Quasi-Kinematic. QKCs are capable of sub-micron repeatability, permit sealing contact as needed in casting, and can be economically mass produced. The design and application of a QKC is demonstrated via a case study on the location of two engine components. Integration of the QKC has improved coupling precision from 5 to 0.7 microns. In addition, this QKC uses 60% fewer precision features, 60% fewer pieces, costs 40% less per engine, and allows feature placement tolerances which are twice as wide as those of the previous dowel-pin-type coupling., by Martin L. Culpepper., S.M.