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

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

A Lamina-Emergent Frustum Using a Bistable Collapsible Compliant Mechanism

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

Bistable aerial platform

A bistable MEMS platform. The bistable MEMS platform converts a rotational input into an ortho-planar displacement and can maintain either it\u27s up or down position without an input force due to bi-stability. The bistable MEMS platform generally includes three components. The first component is a pair of quadrantal bistable mechanisms (QBM). The second is a compliant version of a micro helico-kinematic platform (HKP) that serves to coordinate the motion of the QBM. The third component is an aerial platform, which is a variation of a scissor lift mechanism that attaches to the output of the QBM and amplifies the out-of-plane displacement

Modeling and Parameter Study of Bistable Spherical Compliant Mechanisms

The Bistable Spherical Compliant Mechanisms (BSCM) is a novel device capable of large, repeatable, out-of-plane motion, characteristics that are somewhat difficult to achieve with surface micro-machined MEMS. An improved pseudo-rigid-body model to predict the behavior of the BSCM is presented. The new model was used to analyze seven different versions of the device, each with a different compliant joint length. The new model, which adds torsion, is compared with a Finite-Element beam model. The new model more closely approximates the results yielded by FEA than previous models used to analyze the BSCM. Future work is needed to quantify stress-stiffening interactions between bending and torsion. Both FEA and the current model show that increasing the length of the compliant segment decreases the amount of force required to actuate the device.</jats:p

A Statically Balanced Shape Shifting Surface

This paper presents a concept for producing a Statically Balanced Shape-Shifting Surface (SB-SSS). In this context, an SB-SSS is a surface that can require near-zero magnitude force changes to accomplish a change in shape while retaining effectiveness as a physical barrier. This paper focuses on how to statically balance a specifically-designed compliant mechanism and how to incorporate this mechanism into a polygonal cell. The mechanism consists of a compliant Peaucellier-Lipkin linkage layered with a pre-stressed link as the balancer. Prior art is presented that can show how a polygonal cell can be incorporated into a surface via a tiling array. Specifically shaped overlapping thin plates are used to retain the physical barrier requirement. The demonstration of a virtually zero-force Shape-Shifting Surface (SSS) suggests that SSS’s can be designed with a wide range of force-displacement properties, i.e. ranging from that of a square of the parent material to the zero-force mechanism presented here. Applications for an SB-SSS may be macro-scale or micro-scale and may include sensors, biomedical applications, defense applications, and variable stiffness materials.</jats:p

Developments Toward a Micro Bistable Aerial Platform: Analysis of the Quadrantal Bistable Mechanism

The Bistable Aerial Platform (BAP) functions as a switch in that its platform can lock in two positions, up or down. The Quadrantal Bistable Mechanism (QBM), the principle component of the BAP, is described in detail. A second component of the device, the Helico-Kinematic Platform (HKP), is still under investigation. It is anticipated that the model of the QBM, described here, will be combined with the HKP model, when complete, to form a full model of the Bistable Aerial Platform.</jats:p

Linkage-Based Prosthetic Fingertips: Stability Analysis

The purpose of this study is to analyze linkage- based prosthetic fingertips. The novel design consists of small four-bar mechanisms attached to each section of the opposing fingers replacing what would be the pulp of normal anatomical fingers. The four-bar mechanisms allow the prosthetic hand to conform to the shape of objects during grasp The goal of these prosthetic fingertips is to maximize the functionality of the hand while minimizing the number of inputs that the user has to control. This is crucial in prosthetics where the user may have limited input options, but it may also be useful in robotics. A prosthetic hand has two functions: controlling the orientation of the artificial finger pulps and controlling their position relative to the object. We consider these two functions independently. First, we describe the small four- bar mechanisms which control the orientation of simulated pulps. The stability of the four-bar mechanisms is described as well as their advantages in contrast to a stiff- hinged single link. We then propose concepts for positioning the fingertips in two- and three-finger configurations. The focus of this paper is in the function of the four-bar fingertip mechanism; future research will address the optimal configuration of the fingertips on the hand. The principle method used in this paper is a stability analysis via the principle of virtual work for a crossed four-bar mechanism, and, for comparison purposes, a stiff-hinged dyad. From this analysis we are able to show that four-bar fingertip mechanisms are self-stabilizing for a large range of rotation of the link on which the force is applied and a large range of directions that the force is applied. Stability is indifferent to the magnitude of the force applied to it (assuming that the force does not damage/deform the mechanism)