A modified post-processing technique to design a compliant based microgripper with a plunger using topological optimization
01 Oct 2017-The International Journal of Advanced Manufacturing Technology (Springer London)-Vol. 93, Iss: 1, pp 103-112
TL;DR: In this paper, a compliant mechanism-based micro gripper with a plunger was proposed to push the microobject for an active release during micromanipulation. But, the design of the microgripper was not discussed.
Abstract: The precision of microobject manipulation is predominantly based on the appropriate design of micromanipulation devices such as microgrippers. A compliant mechanism-based microgripper is an appropriate choice to achieve a highly precise and controlled motion. This research article proposes a refined technique to design a compliant-based microgripper with a plunger. The topological optimization technique has been adopted in this research work to develop the conceptual design of the mechanism. Flexure hinges are introduced in the topologically optimized design to overcome the senseless regions developed during the optimization process which is highly complicated to manufacture. Various flexure hinge contours such as rectangular, circular, and elliptical are introduced in the conceptual design domain, and their effects are investigated. Various parameters of flexure hinges are considered; the stress, the displacements, and the strain energy stored in the mechanism are studied through finite element analysis (FEA). In addition to FEA, experimental verification of the design was also performed. Both results are convincing about the structural performance of the microgripper design. In general, microdevices possess higher surface forces than volumetric forces; hence, this design is introduced with a plunger segment which is used to push the microobject for an active release during micromanipulation.
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TL;DR: A survey of the state-of-the-art design advances in this research area over the past 20 years is presented and can be helpful to those engaged in the topology optimization of compliant mechanisms who desire to be apprised of the field’s recent state and research tendency.
198 citations
TL;DR: In this article, a piezoelectric actuated compliant micro gripper was designed to get a large jaw motion stroke, and a three-stage flexure-based amplification composed of the homothetic bridge and leverage mechanisms was developed and the key structure parameters were optimized.
Abstract: The design and control of a novel piezoelectric actuated compliant microgripper is studied in this paper to achieve fast, precise, and robust micro grasping operations. First, the microgripper mechanism was designed to get a large jaw motion stroke. A three-stage flexure-based amplification composed of the homothetic bridge and leverage mechanisms was developed and the key structure parameters were optimized. The microgripper was manufactured using the wire electro discharge machining technique. Finite element analysis and experimental tests were carried out to examine the performance of the microgripper mechanism. The results show that the developed microgripper has a large amplification factor of 22.6. Dynamic modeling was conducted using experimental system identification, and the displacement and force transfer functions were obtained. The position/force switching control strategy was utilized to realize both precision position tracking and force regulation. The controller composed of an incremental proportional-integral-derivative control and a discrete sliding mode control with exponential reaching law was designed based on the dynamic models. Experiments were performed to investigate the control performance during micro grasping process, and the results show that the developed compliant microgripper exhibits good performance, and fast and robust grasping operations can be realized using the developed microgripper and controller.
126 citations
Cites methods from "A modified post-processing techniqu..."
...as the displacement amplifications, and topologically optimized design has been carried out for some microgripper mechanisms [23], [24]....
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TL;DR: In this article, the authors proposed a manufacturability evaluation method adapted for the use of molds and integrated this evaluation method with topology optimization and proposed a scheme for imposing a molding constraint within the topological optimization procedure.
Abstract: Manufacturing methods using molds, such as casting and injection molding, are widely used in industries. A basic requirement when using such manufacturing methods is that design engineers must design products so that they incorporate certain geometrical features that allow the mold parts to be removed from the created solid object. In the present study, we propose a manufacturability evaluation method especially adapted for the use of molds. To evaluate the manufacturability, we introduce fictitious physical models that are described by steady-state anisotropic advection-diffusion equations. In these fictitious physical models, material domains have a virtual source term and the advection directions are aligned with the directions along which the mold parts are parted. Void regions, where the values of all fictitious physical fields are high, then represent either undercut geometries that would prevent the mold from being released, or interior voids that cannot be cast. Consequently, manufacturability can be evaluated using these fictitious physical fields. Furthermore, in the present study, we integrate this evaluation method with topology optimization and propose a scheme for imposing a molding constraint within the topology optimization procedure. This newly proposed topology optimization method can consider the position of mold parting lines prior to the detailed optimization procedure. Several numerical examples are provided to demonstrate the validity and effectiveness of the proposed method.
35 citations
Cites background from "A modified post-processing techniqu..."
...As a result, when topology optimization solutions are applied in practical manufacturing circumstances, design engineers often must interpret and modify the results to satisfy manufacturability conditions [24]....
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TL;DR: In this article, the authors reviewed the recent advances on performance indices, classification, structural composition, optimization and modeling method, and control of PEACM and provided a guideline on further development of the micro gripper.
Abstract: The piezoelectric-actuated compliant microgripper (PEACM) plays an essential role in the application fields such as biomedical engineering, microelectronics, and optical engineering. As compared with other categories of grippers, PEACM exhibits the advantages of high accuracy of displacement, large power to weight ratio, low energy consumption, and fast response speed. This paper reviews the recent advances on performance indices, classification, structural composition, optimization and modeling method, and control of PEACM. First, the gripper's performance indices and classifications are elaborated, which is beneficial to determine the design goal. Then, the compliant mechanisms adopted in the microgripper design are discussed, including the flexible hinge, displacement amplifier, and guiding mechanism. In addition, the optimization and modeling methods of the microgripper are presented. Popular types of position/force sensors and different displacement/force control strategies employed in the microgripper are surveyed. Moreover, the prospect on future development trend of the PEACM is discussed. The paper provides the reader with an overview of the recent advances on PEACM design and also a guideline on further development of the microgripper.
32 citations
TL;DR: Investigation of elasto-kinematic hinge and mechanism properties in dependence of scaling the geometric parameters regarding the impact of using optimized flexure hinge contours within a unified synthesis method without the need of rerunning simulations shows that optimized flexures are promising for miniaturized compliant mechanisms with high precision and large stroke at once.
24 citations
References
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Book•
17 Sep 2011
TL;DR: In this article, the authors proposed a topology optimization by distribution of isotropic material for truss structures with anisotropic materials, based on the topology design of truss structure.
Abstract: 1 Topology optimization by distribution of isotropic material- 2 Extensions and applications- 3 Design with anisotropic materials- 4 Topology design of truss structures- 5 Appendices- 6 Bibliographical notes- References- Author Index
4,881 citations
"A modified post-processing techniqu..." refers background or methods in this paper
...The monolithic compliant mechanism design has been developed by adopting various approaches such as mechanism synthesis [5, 6], pseudo-rigid body model [7], optimization technique [8], inverse methods [9], and intuitive method [10]....
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...[8] is modified according to the initial design domain and the necessary boundary conditions....
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...Bendsoe and Sigmund [8] implemented SIMP or power law interpolation approach alternate to a homogenization-based method....
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Book•
27 Nov 2002TL;DR: The second edition of Compliant Mechanisms: Design of Flexure Hinges as mentioned in this paper provides practical answers to the design and analysis of devices that incorporate flexible hinges by means of a bottom-up compliance (flexibility) approach.
Abstract: With a rigorous and comprehensive coverage, the second edition of Compliant Mechanisms: Design of Flexure Hinges provides practical answers to the design and analysis of devices that incorporate flexible hinges. Complex-shaped flexible-hinge mechanisms are generated from basic elastic segments by means of a bottom-up compliance (flexibility) approach. The same compliance method and the classical finite element analysis are utilized to study the quasi-static and dynamic performances of these compliant mechanisms. This book offers easy-to-use mathematical tools to investigate a wealth of flexible-hinge configurations and two- or three-dimensional compliant mechanism applications.
FEATURES
Introduces a bottom-up compliance-based approach to characterize the flexibility of new and existing flexible hinges of straight- and curvilinear-axis configurations
Develops a consistent linear lumped-parameter compliance model to thoroughly describe the quasi-static and dynamic behavior of planar/spatial, serial/parallel flexible-hinge mechanisms
Utilizes the finite element method to analyze the quasi-statics and dynamics of compliant mechanisms by means of straight- and curvilinear-axis flexible-hinge elements
Covers miscellaneous topics such as stress concentration, yielding and related maximum load, precision of rotation of straight- and circular-axis flexible hinges, temperature effects on compliances, layered flexible hinges and piezoelectric actuation/sensing
Offers multiple solved examples of flexible hinges and flexible-hinge mechanisms.
This book should serve as a reference to students, researchers, academics and anyone interested to investigate precision flexible-hinge mechanisms by linear model-based methods in various areas of mechanical, aerospace or biomedical engineering, as well as in robotics and micro-/nanosystems.
651 citations
05 Aug 1995
TL;DR: It appears that it will be difficult to overcome adhesion effects for the smallest parts, so manipulation of parts on the order of 10 micron or smaller may best be done in a fluid medium using techniques such as laser trapping, or dielectrophoresis.
Abstract: When parts to be handled are less than one millimeter in size, adhesive forces between gripper and object can be significant compared to gravitational forces. These adhesive forces arise primarily from surface tension, Van der Waals, and electrostatic attractions and can be a fundamental limitation to part handling in a gas environment. While it is possible to fabricate miniature versions of conventional robot grippers, for example from polysilicon, it appears that it will be difficult to overcome adhesion effects for the smallest parts. Thus, manipulation of parts on the order of 10 micron or smaller may best be done in a fluid medium using techniques such as laser trapping, or dielectrophoresis.
469 citations
TL;DR: In this article, the drawbacks of typical flexure connectors are investigated and cataloged, and several new designs for highly effective, kinematically-behaved compliant joints are proposed.
Abstract: Flexure joints are widely used to approximate the function of traditional mechanical joints, while offering the benefits of high precision, long life, and ease of manufacture. This paper investigates and catalogs the drawbacks of typical flexure connectors and presents several new designs for highly-effective, kinematically-behaved compliant joints. A revolute and a translational compliant joint are proposed (Figure 1), both of which offer great improvements over existing flexures in the qualities of (1) large range of motion, (2) minimal axis drift, (3) increased off-axis stiffness, and (4) reduced stress-concentrations. Analytic stiffness equations are developed for each joint and parametric computer models are used to verify their superior stiffness properties. A catalog of design charts based on the parametric models is also presented, allowing for rapid sizing of the joints for custom performance. Finally, two multi-degree-of-freedom joints are proposed as modifications to the revolute joint. These include a compliant universal joint and a compliant spherical joint, both designed to provide high degrees of compliance in the desired direction of motion and high stiffness in other directions.Copyright © 2002 by ASME
339 citations
"A modified post-processing techniqu..." refers background in this paper
...Table 1 Notch joint comparisons: leaf hinge, circular, and elliptical [26]...
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...The range ofmotion, the amount of axis drift, the ratio of off-axis stiffness to axial stiffness, and the stress concentration effects are important criteria dominating the precision motion of the compliant mechanism [26]....
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TL;DR: In this paper, closed-form compliance equations for conic-section flexure hinges were developed to predict the deformation/displacement field of a flexure hinge under loading and to assess the precision of rotation for a specific conic hinge.
189 citations
"A modified post-processing techniqu..." refers background in this paper
...Generally, flexures are a straight beam or notches with different contours such as conic sections [21]; circular, elliptical, parabolic [22], and hyperbolic contour [22]; v-shaped notches [23]; quadratic rational B’ezier curves [24]; and polynomial contour [25]....
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