93 research outputs found

    DETC2006-99076 SPHERICAL BISTABLE MICROMECHANISM

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    Towards a framework for attention cueing in instructional animations: Guidelines for research and design

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    This paper examines the transferability of successful cueing approaches from text and static visualization research to animations. Theories of visual attention and learning as well as empirical evidence for the instructional effectiveness of attention cueing are reviewed and, based on Mayer’s theory of multimedia learning, a framework was developed for classifying three functions for cueing: (1) selection—cues guide attention to specific locations, (2) organization—cues emphasize structure, and (3) integration—cues explicate relations between and within elements. The framework was used to structure the discussion of studies on cueing in animations. It is concluded that attentional cues may facilitate the selection of information in animations and sometimes improve learning, whereas organizational and relational cueing requires more consideration on how to enhance understanding. Consequently, it is suggested to develop cues that work in animations rather than borrowing effective cues from static representations. Guidelines for future research on attention cueing in animations are presented

    Shape-shifting surfaces

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    Shape-shifting surfaces that retain their effectiveness as physical barriers while undergoing changes in shape. The shape changes include any motion that makes the surface more effective at performing its function, such as expansion, shrinkage, twisting, encircling, wiggling, swallowing or constricting. The shape-shifting surfaces include tiled arrays of polygonal cells, each cell including specifically-designed compliant flexures attached to specifically-shaped overlapping thin plates or shells. Applications for such surfaces include micro-scale cellular engineering and macro-scale biomedical applications, recreational uses, national security, and environmental protection

    Linear bi-stable compliant crank-slider-mechanism

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    A linear element with two stable points, it can be used as trust element allows for change in length. It can transform structure from one shape to another thus allowing for morphable configuration. A new model is presented herein for a linear bi-stable compliant mechanism and design guidelines for its use. The mechanism is based on the crank-slider mechanism. This model takes into account the first mode of buckling and post-buckling behavior of a compliant segment to describe the mechanism\u27s hi-stable behavior. The kinetic and kinematic equations, derived from the Pseudo-Rigid-Body Model, were solved numerically and are represented in plots. This representation allows the generation of step-by-step design guidelines. Because different applications may have different input requirements, two different design approaches are described herein with different parameters subsets as inputs

    Linear bi-stable compliant crank-slider-mechanism

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    A linear element with two stable points, it can be used as trust element allows for change in length. It can transform structure from one shape to another thus allowing for morphable configuration. A new model is presented herein for a linear bi-stable compliant mechanism and design guidelines for its use. The mechanism is based on the crank-slider mechanism. This model takes into account the first mode of buckling and post-buckling behavior of a compliant segment to describe the mechanism\u27s bi-stable behavior. The kinetic and kinematic equations, derived from the Pseudo-Rigid-Body Model, were solved numerically and are represented in plots. This representation allows the generation of step-by-step design guidelines. Because different applications may have different input requirements, two different design approaches are described herein with different parameters subsets as inputs

    Shape-morphing space frame apparatus using linear bistable elements

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    A shape-morphing space frame (SMSF) utilizing the linear bistable compliant crank-slider mechanism (LBCCSM). The frame\u27s initial shape is constructed from a single-layer grid of flexures, rigid links and LBCCSMs. The grid is bent into the space frame\u27s initial cylindrical shape, which can morph because of the inclusion of LBCCSMs in its structure. The design parameters include the frame\u27s initial height, its tessellation pattern (including the unit cell bistable elements\u27 placement), its initial diameter, and the resulting desired shape. The method used in placing the unit cell bistable elements considers the principle stress trajectories. Two different examples of shape-morphing space frames are presented herein, each starting from a cylindrical-shell space frame and morphing, one to a hyperbolic-shell space frame and the other to a spherical-shell space frame, both morphing by applying moments, which shear the cylindrical shell, and forces, which change the cylinder\u27s radius using Poisson\u27s effect

    A Lamina-Emergent Frustum Using a Bistable Collapsible Compliant Mechanism

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    This paper presents a new bistable collapsible compliant mechanism (BCCM) that is utilized in a lamina-emergent frustum. The mechanism is based on transforming a polygon spiral into spatial frustum shape using a mechanism composed of compliant links and joints that exhibits a bistable behavior. A number of mechanism types (graphs) were considered to implement the shape-morphing spiral, including 4-bar, 6-bar, and 8-bar chains. Our design requirements permitted the selection of a particular 8-bar chain as the basis for the BCCM. The bistable behavior was added to the mechanism by introducing a snap-through bistability as the mechanism morphs. A parametric CAD was used to perform the dimensional synthesis. The design was successfully prototyped. We anticipate that the mechanism may be useful in commercial small animal enclosures or as a frame for a solar still
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