Cylindrical Single-Degree-of-Freedom Spatial Mechanisms for Cell Restraint

2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Gregory H. Teichert ◽  
Quentin T. Aten ◽  
Sandra H. Burnett ◽  
Larry L. Howell ◽  
Brian D. Jensen
Keyword(s):  
Transgenic Animal ◽  
Degree Of Freedom ◽  
Surface Micromachining ◽  
Electromechanical Systems ◽  
Single Degree Of Freedom ◽  
Spatial Mechanism ◽  
Single Degree ◽  
Spatial Mechanisms ◽  
Production Techniques ◽  
Cell Support

Many transgenic animal production techniques require egg cells to be held in place during injection of the transgene. This paper presents a micro-electromechanical systems (MEMS) mechanism that provides cell support, self-centers the cell, and requires a single linear input for actuation. This restraint device uses an innovative spatial mechanism, termed a cylindrical mechanism. The kinematics and design of the restraint are discussed. The MEMS cell restraints were fabricated using a surface micromachining process, after which the mechanism’s cell support, self-centering of the cell, and motion were verified.

Kinematic Analysis of Spatial Mechanisms by Means of Screw Coordinates. Part 2—Analysis of Spatial Mechanisms

1971 ◽  
Vol 93 (1) ◽  
pp. 67-73 ◽  
Author(s):  
M. S. C. Yuan ◽  
F. Freudenstein ◽  
L. S. Woo
Keyword(s):  
Computer Program ◽  
Kinematic Analysis ◽  
Static Force ◽  
Single Degree Of Freedom ◽  
Numerical Examples ◽  
Spatial Mechanism ◽  
Single Degree ◽  
Spatial Mechanisms ◽  
Torque Analysis ◽  
Basic Concepts

The basic concepts of screw coordinates described in Part I are applied to the numerical kinematic analysis of spatial mechanisms. The techniques are illustrated with reference to the displacement, velocity, and static-force-and-torque analysis of a general, single-degree-of-freedom spatial mechanism: a seven-link mechanism with screw pairs (H)7. By specialization the associated computer program is capable of analyzing many other single-loop spatial mechanisms. Numerical examples illustrate the results.

Four-Position Synthesis for Spatial Mechanisms With Two Independent Loops

1992 ◽  
Author(s):  
Chien H. Chiang ◽  
Wei Hua Chieng ◽  
David A. Hoeltzel
Keyword(s):  
Rigid Body ◽  
Mathematical Models ◽  
Analytical Methods ◽  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Practical Applications ◽  
Single Degree ◽  
Spatial Mechanisms ◽  
Position Synthesis ◽  
Independent Loops

Abstract Mathematical models that have been employed to synthesize spatial mechanisms for rigid body guidance have been found to be too complicated to implement in practical applications, especially for four-position guidance synthesis. This paper describes simple analytical methods for synthesizing single degree-of-freedom spatial mechanisms having two independent loops for four precision positions. In addition, prescribed timing has been simultaneously considered for several spatial mechanisms.

Rigidly Foldable Thick Origami Using Designed-Offset Linkages

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Robert J. Lang ◽  
Nathan Brown ◽  
Brian Ignaut ◽  
Spencer Magleby ◽  
Larry Howell
Keyword(s):  
Plate Thickness ◽  
Degree Of Freedom ◽  
Unique Combination ◽  
Single Degree Of Freedom ◽  
Spatial Mechanism ◽  
Single Degree ◽  
Unfolded State ◽  
The Individual ◽  
Kinematic Motion

Abstract We present new families of thick origami mechanisms that achieve rigid foldability and parallel stacking of panels in the flat-folded state using linkages for some or all of the hinges between panels. A degree-four vertex results in a multiloop eight-bar spatial mechanism that can be analyzed as separate linkages. The individual linkages are designed so that they introduce offsets perpendicular to the panels that are mutually compatible around each vertex. This family of mechanisms offers the unique combination of planar unfolded state, parallel-stacked panels in the flat-folded state and kinematic single-degree-of-freedom motion from the flat-unfolded to the flat-folded state. The paper develops the mathematics defining the necessary offsets, beginning with a symmetric bird’s-foot vertex, and then shows that the joints can be developed for asymmetric flat-foldable systems. Although in the general case there is no guarantee of achieving perfect kinematic motion, we show that for many cases of interest, the deviation is a tiny fraction of the plate thickness. Mechanical realizations of several examples are presented.

Mechanism Link Rotatability and Limit Position Analysis Using Polynomial Discriminants

1987 ◽  
Vol 109 (2) ◽  
pp. 178-182 ◽  
Author(s):  
R. L. Williams ◽  
C. F. Reinholtz
Keyword(s):  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Position Analysis ◽  
Numerical Example ◽  
Single Degree ◽  
Spatial Mechanisms ◽  
Limit Position

A theory is proposed for algebraically determining the limit positions of single-degree-of-freedom mechanisms. The absence of limit positions indicates that the link being considered is a fully rotating crank. This theory is applied in the present paper to the RSSR and RRSS spatial mechanisms. Conditions for spatial mechanisms analogous to Grashof’s law should be attainable using this theory. A numerical example is given to illustrate the theory.

Rigidly Foldable Thick Origami Using Designed-Offset Linkages

2019 ◽  
Author(s):  
Robert J. Lang ◽  
Nathan Brown ◽  
Brian Ignaut ◽  
Spencer Magleby ◽  
Larry Howell
Keyword(s):  
Degree Of Freedom ◽  
Unique Combination ◽  
Single Degree Of Freedom ◽  
Spatial Mechanism ◽  
Single Degree ◽  
Unfolded State ◽  
The Individual

Abstract We present new families of thick origami mechanisms that achieve rigid foldability and parallel stacking of panels in the flat-folded state using linkages for some or all of the hinges between panels. A degree-four vertex results in a multi-loop eight-bar spatial mechanism that can be analyzed as separate linkages. The individual linkages are designed so that they introduce offsets perpendicular to the panels that are mutually compatible around each vertex. This family of mechanisms offers the unique combination of a planar unfolded state, parallel-stacked panels in the flat folded state, and kinematic single-degree-of-freedom motion from the flat-unfolded to the flat-folded state.

A Machine Learning Approach to Solving the Alt-Burmester Problem for Synthesis of Defect-free Spatial Mechanisms

2021 ◽  
pp. 1-14
Author(s):  
Shashank Sharma ◽  
Anurag Purwar
Keyword(s):  
Machine Learning ◽  
Learning Algorithm ◽  
Degree Of Freedom ◽  
Synthesis Problem ◽  
Machine Learning Algorithm ◽  
Motion Synthesis ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Spatial Mechanisms ◽  
Machine Learning Approach

Abstract In this paper, we present a machine-learning algorithm to synthesize defect-free single degree of freedom spatial mechanisms for the Alt-Burmester problem. The Alt-Burmester problem is a generalization of a pure motion synthesis problem to include via path-points with missing orientations. While much work has been done towards the synthesis of planar and, to some extent, spherical mechanisms, the generation of mechanisms that are free of circuit, branch, and order defects has proven to be a difficult task. This is even more challenging for spatial mechanisms, which can consist of a large number of circuits and branches. Moreover, the Alt-Burmester problem makes solving such problems using an analytical approach further demanding. In this paper, we present a novel machine-learning algorithm for solving the Alt-Burmester problem for spatial 5-SS platform mechanism using a Variational Auto-Encoder (VAE) architecture. The VAE helps capture the relationship between path and orientation properties of the motion of the 5-SS mechanisms, which enables reformulating the Alt-Burmester problem into a pure motion synthesis problem. The end goal is to produce defect-free spatial mechanism design solutions. While our focus in this paper is on the 5-SS mechanisms, this approach can be scaled to any single-degree-of-freedom spatial mechanisms.

Synthesis of Spatial Mechanism UR-2SS for Path Generation

2015 ◽  
Vol 7 (4) ◽  
Author(s):  
Wen-Yeuan Chung
Keyword(s):  
Three Dimensional ◽  
Kinematic Chain ◽  
Degree Of Freedom ◽  
Path Generation ◽  
Single Degree Of Freedom ◽  
Numerical Examples ◽  
Spatial Mechanism ◽  
Single Degree ◽  
Three Stages ◽  
Moving Platform

This article presents a new spatial mechanism with single degree of freedom (DOF) for three-dimensional path generation. The path can be defined by prescribing at most seven precision points. The moving platform of the mechanism is supported by a U-R (universal-revolute) leg and two S–S (spherical–spherical) legs. The driving unit is the first axis of the universal pair. The U-R leg is synthesized first with the problem of order defects being considered. Precision points then lead to prescribed poses of the moving platform. Two S–S legs are then synthesized to meet these poses. This spatial mechanism with a given input is analogous to a planar kinematic chain so that all possible configurations of the spatial mechanism can be constructed. A strategy consisting of three stages for evaluating branch defects is developed with the aid of the characteristic of double configurations and the technique of coding three constituent four-bar linkages. Two numerical examples are presented to illustrate the design, the evaluation of defects, and the performance of the mechanism.

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