scholarly journals Optimization Parameter for Micro-Gripper Based on Triple-Stair Compliant Mechanism Using GTs-TOPSIS

2021 ◽  
Author(s):  
Chia–Nan Wang ◽  
Thi Diem-My Le
Keyword(s):  
Compliant Mechanism ◽  
Optimization Method ◽  
Maximum Output ◽  
Clamping Force ◽  
Force Output ◽  
Maximum Displacement ◽  
Output Displacement ◽  
Amplification Ratio ◽  
Relationship Analysis ◽  
Order Preference

Abstract In manipulating the assembly of micro-components, the symmetrical microgripper mechanism often causes destruction, damaging the micro-components during manipulation. The reason is due to the phenomenon of non-uniform clamping force output of the clamp. From this disadvantage, a new asymmetric microgripper structure is proposed with stable output clamping force. The asymmetric microgripper structure will have a smaller output displacement than the symmetric structure. Therefore, to increase the output displacement gain, a flexible hinge with a triple stair half bridge-style mechanism is adopted to design the amplifier of the asymmetrical microgripper. The finite element method is applied to analyze the displacement and stress. The optimization process is performed based on the geometric parametric properties of the structure. Using the technology for order preference by similarity to ideal solution (TOPSIS) based on the grey relationship analysis (GRA) obtained the maximal displacement output and minimal stress. The results show that the maximum output displacement is 5,818 mm, stress after analysis is 2,432MPa. The test is conducted to verify the optimal results and the effectiveness of the optimization method. Finally, experimental experiments were performed, with a 4.8% difference from the FEA results. The results from the experimental test verify that the microgripper's maximum displacement amplification ratio is approximately 58.2 times.

scholarly journals Research on three-stage amplified compliant mechanism-based piezo-driven microgripper

2020 ◽  
Vol 12 (3) ◽  
pp. 168781402091147 ◽  
Author(s):  
Xiaodong Chen ◽  
Zilong Deng ◽  
Siya Hu ◽  
Xingjun Gao ◽  
Jinhai Gao
Keyword(s):  
Amplification Factor ◽  
Compliant Mechanism ◽  
Structural Parameters ◽  
Maximum Output ◽  
Driving Voltage ◽  
Element Analysis ◽  
Compact Structure ◽  
Output Displacement ◽  
Amplification Ratio ◽  
Input Variables

The microgripper based on the principle of lever amplification is easy to realize; however, the theoretical amplification factor is limited by the space size and the structure is not compact enough. The microgripper based on the triangular amplification principle has a compact structure and high amplification factor, but it is not conducive to miniaturization design. Considering compactness, parallel clamping, high magnification, and miniaturization design, a three-stage amplifier consisting of a semi-rhombic amplifier and lever amplifiers is designed. To begin with, the theoretical amplification ratio and the relationship between input variables and output variables are calculated by energy method. Furthermore, the finite element analysis software is used to optimize the structural parameters and analyze the performance of the model. Lastly, the experimental verification is carried out. At 150 V of driving voltage, the maximum output displacement was 530mm, and the actual magnification was 24 times. Microparts can be gripped in parallel and stably, which confirms the validity of the design.

An Evolutionary Soft-Add Topology Optimization Method for Synthesis of Compliant Mechanisms With Maximum Output Displacement

2017 ◽  
Vol 9 (5) ◽  
Author(s):  
Chih-Hsing Liu ◽  
Guo-Feng Huang ◽  
Ta-Lun Chen
Keyword(s):  
Topology Optimization ◽  
Compliant Mechanisms ◽  
Volume Fraction ◽  
Compliant Mechanism ◽  
Optimization Method ◽  
Computational Time ◽  
Maximum Output ◽  
Spring Stiffness ◽  
Output Displacement ◽  
Topology Optimization Method

This paper presents an evolutionary soft-add topology optimization method for synthesis of compliant mechanisms. Unlike the traditional hard-kill or soft-kill approaches, a soft-add scheme is proposed in this study where the elements are equivalent to be numerically added into the analysis domain through the proposed approach. The objective function in this study is to maximize the output displacement of the analyzed compliant mechanism. Three numerical examples are provided to demonstrate the effectiveness of the proposed method. The results show that the optimal topologies of the analyzed compliant mechanisms are in good agreement with previous studies. In addition, the computational time can be greatly reduced by using the proposed soft-add method in the analysis cases. As the target volume fraction in topology optimization for the analyzed compliant mechanism is usually below 30% of the design domain, the traditional methods which remove unnecessary elements from 100% turn into inefficient. The effect of spring stiffness on the optimized topology has also been investigated. It shows that higher stiffness values of the springs can obtain a clearer layout and minimize the one-node hinge problem for two-dimensional cases. The effect of spring stiffness is not significant for the three-dimensional case.

Parametric Study of Circular Micro Flexure Hinge Design

2006 ◽  
Author(s):  
Sarin Shrestha ◽  
Raymond K. Yee
Keyword(s):  
Finite Element ◽  
Parametric Study ◽  
Compliant Mechanism ◽  
Flexure Hinge ◽  
Finite Element Models ◽  
Maximum Output ◽  
Maximum Displacement ◽  
Output Displacement ◽  
Design Guide ◽  
Hinge Model

Compliant mechanism is a monolithic device that utilizes flexible elements, instead of pins, to transform the input to a useful output position, and flexure hinge is an integral part of a compliant mechanism. Flexure hinge design is important because it provides a means for motion actuation in a mechanism. An ideal design of a flexure hinge for a displacement output mechanism is that it provides maximum displacement output with minimum input. The objective of this study is to establish a design guide based on stiffness, displacement, and stresses for a generalized circular micro flexure hinge model using finite element method. Parametric study of a circular flexure hinge was performed using ABAQUS finite element code. The finite element results were compared with relevant analytical model from literature. Micro flexure hinge finite element models with selected range of dimensions for study were evaluated, and the optimal dimensions for flexure hinge design for maximum output displacement and minimum stresses were identified. From this study, the following parameters were established as design guide for a circular micro flexure hinge. With the width (w) of a circular flexure from 300 to 500μm range, our recommended flexure hinge height (h) is twice of the width, and the flexure hinge thickness ratio (b/t) is about 10.

scholarly journals Design of a Compliant Mechanism Based Four-Stage Amplification Piezoelectric-Driven Asymmetric Microgripper

Micromachines ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 25
Author(s):  
Xiaodong Chen ◽  
Zilong Deng ◽  
Siya Hu ◽  
Jinhai Gao ◽  
Xingjun Gao
Keyword(s):  
Compliant Mechanism ◽  
Experimental Tests ◽  
Element Analysis ◽  
Output Displacement ◽  
Amplification Ratio ◽  
Output Force ◽  
Characteristics Analysis ◽  
The Relationship ◽  
Two Sides ◽  
Theoretical Results

The existing symmetrical microgrippers have larger output displacements compared with the asymmetrical counterparts. However, the two jaws of a symmetrical microgripper are less unlikely to offer the same forces on the two sides of a grasped micro-object due to the manufacture and assembly errors. Therefore, this paper proposes a new asymmetric microgripper to obtain stable output force of the gripper. Compared with symmetrical microgrippers, asymmetrical microgrippers usually have smaller output displacements. In order to increase the output displacement, a compliant mechanism with four stage amplification is employed to design the asymmetric microgripper. Consequently, the proposed asymmetrical microgripper possesses the advantages of both the stable output force of the gripper and large displacement amplification. To begin with, the mechanical model of the microgripper is established in this paper. The relationship between the driving force and the output displacement of the microgripper is then derived, followed by the static characteristics’ analysis of the microgripper. Furthermore, finite element analysis (FEA) of the microgripper is also performed, and the mechanical structure of the microgripper is optimized based on the FEA simulations. Lastly, experimental tests are carried out, with a 5.28% difference from the FEA results and an 8.8% difference from the theoretical results. The results from theoretical calculation, FEA simulations, and experimental tests verify that the displacement amplification ratio and the maximum gripping displacement of the microgripper are up to 31.6 and 632 μm, respectively.

scholarly journals On the design of a novel fully compliant spherical four-bar mechanism

2019 ◽  
Vol 11 (9) ◽  
pp. 168781401987954
Author(s):  
Volkan Parlaktaş ◽  
Engin Tanık ◽  
Çağıl Merve Tanık
Keyword(s):  
Compliant Mechanism ◽  
Design Method ◽  
Optimization Method ◽  
Maximum Output ◽  
Element Analysis ◽  
Free Position ◽  
Flexural Hinges ◽  
Arc Lengths ◽  
The Relationship ◽  
Novel Design

In this article, a novel fully compliant spherical four-bar mechanism is introduced and its generalized design methodology is proposed. The original fully compliant mechanism lies on a plane at the free position (undeflected position); therefore, it has the advantages of ease of manufacturing, minimized parts, and no backlash. First, the mobility conditions of the mechanism are obtained. The dimensions of the mechanism are optimally calculated for maximum output rotation, while keeping the deflection of flexural hinges at an acceptable range. Using an optimization method, design tables are prepared to display the relationship between arc lengths and corresponding deflections of flexural hinges. Input–output torque relationship and stresses at compliant segments are obtained analytically. A mechanism dimensioned by this novel design method is analyzed by a finite element analysis method, and the analytical results are verified. Finally, the mechanism is manufactured and it is ensured that the deflections of the compliant segments are consistent with the theoretical results.

scholarly journals Preparation and characterization analysis of carbon nanotubes and graphene electrode modified carbon nanotubes reinforced IPMC

2021 ◽  
Vol 13 (8) ◽  
pp. 168781402110407
Author(s):  
Jintao Zhao ◽  
Junpeng Shao ◽  
Zhenjie Zhang ◽  
Bo Liang ◽  
Xiaoxiao Liu
Keyword(s):  
Carbon Nanotubes ◽  
Real Life ◽  
Maximum Output ◽  
Maximum Displacement ◽  
Output Displacement ◽  
Driving Mode ◽  
Output Force ◽  
New Type ◽  
Modified Carbon Nanotubes ◽  
Exchange Membrane

IPMC is a new type of polymer material that will act violently to the stimulation of electrical signals. IPMC has changed the traditional mechanical driving mode. However, the development of IPMC is limited by factors like manufacture cost. In order to reduce the manufacture cost of IPMC, improve the output displacement and output force of IPMC, and make IPMC closer to real life, in this paper, we use carbon nanotubes to modify the ion exchange membrane of IPMC, and PDDA to modify carbon nanotubes and graphene. A graphite plated electrode and a carbon nanotube electrode were coated on a platinum plated IPMC. The common modified Pt-IPMC, carbon nanotubes modified Pt-IPMC, carbon nanotubes modified GS-IPMC, and carbon nanotubes modified CNT-IPMC were prepared. Through the experiment, it is found that the maximum output displacement of GS-IPMC modified by carbon nanotubes is 4.9 mm, and the maximum output force is 39 mN. The output displacement of ordinary Pt IPMC is 3.18 mm and the maximum output force is 31 mN. The maximum displacement and output force of GS-IPMC modified by CNTs are higher than those of Pt IPMC, which is more suitable for research and application.

scholarly journals A type of symmetrical differential lever displacement amplification mechanism

2021 ◽  
Vol 22 ◽  
pp. 5
Author(s):  
Wei Fan ◽  
Huaxue Jin ◽  
Yuchen Fu ◽  
Yuyang Lin
Keyword(s):  
Natural Frequency ◽  
Scientific Basis ◽  
Maximum Output ◽  
Driving Frequency ◽  
Element Analysis ◽  
Symmetrical Structure ◽  
Output Displacement ◽  
Amplification Ratio ◽  
Drive Control ◽  
Amplification Mechanism

The paper proposes a type of symmetrical flexure hinge displacement amplification mechanism, which is based on the differential lever to effectively improve the displacement output stroke of the PZT and reduce the additional displacement. In addition to describes the working principle of the differential displacement amplification, it establishes the semi-model of the micro-displacement amplification mechanism according to the symmetrical structure. The stiffness, displacement loss, and natural frequency of the amplification mechanism are simulated by finite element analysis (FEA). Simultaneously, build the mathematical model of amplification ratio to obtain the optimal driving frequency when the natural frequency is 930.58 Hz. The maximum output displacement of the designed mechanism is 313.05 µm and the amplification ratio is 6.50. Due to the symmetrical structure, the output additional displacement of the whole amplification mechanism is small.It provides a scientific basis for further improving the positioning accuracy of the micro/nano drive control system.

scholarly journals Adapting ant colony optimization of compliant structures using elements with linearly varying cross-sections

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Nadim Diab ◽  
Farah Jouni
Keyword(s):  
Ant Colony Optimization ◽  
Cross Section ◽  
Cross Sections ◽  
Compliant Mechanism ◽  
Optimization Technique ◽  
Ant Colony ◽  
Internal Stresses ◽  
Output Displacement ◽  
Amplification Ratio ◽  
Stiffness Matrices

AbstractThis work addresses the design of miniature compliant displacement amplifiers. The optimum design of the compliant mechanism is generated through topology optimization of two-node frame elements with linearly varying cross sections using the Ant Colony Optimization technique. First, stiffness matrices that account for the change in the cross-section dimensions are formulated. Then, each element is assigned 5 independent ants that represent its design variables defined as the width and thickness of each of the two peripheral cross-sections in addition to the material density. Three case studies with customized cost functions are furnished; the first maximizes the amplification ratio, the second maximizes the output displacement, while the third maximizes both amplification ratio and output displacement simultaneously. The resulting micro-compliant amplifiers are more compact in volume and surpass their constant cross-section counterparts in terms of amplification ratio and output displacement while keeping relatively low internal stresses. The performances of all optimized topologies are verified through ANSYS.

A Topology Optimization Method With Constant Volume Fraction During Iterations for Design of Compliant Mechanisms

2016 ◽  
Vol 8 (4) ◽  
Author(s):  
Chih-Hsing Liu ◽  
Guo-Feng Huang
Keyword(s):  
Topology Optimization ◽  
Compliant Mechanisms ◽  
Volume Fraction ◽  
Optimization Method ◽  
Benchmark Problems ◽  
Maximum Output ◽  
Output Displacement ◽  
Calculated Volume ◽  
Traditional Approaches ◽  
Topology Optimization Method

This study presents a topology optimization method for design of complaint mechanisms with maximum output displacement as the objective function. Unlike traditional approaches, one special characteristic of this method is that the volume fraction, which is defined as the calculated volume divided by the full volume, remains the same value throughout the optimization process based on the proposed pseudodensity and sensitivity number update scheme. The pseudodensity of each element is initially with the same value as the prespecified volume fraction constraint and can be decreased to a very small value or increased to one with a small increment. Two benchmark problems, the optimal design of a force–displacement inverter mechanism and a crunching mechanism, are provided as the illustrative examples to demonstrate the effectiveness of the proposed method. The results agree well with the previous studies. The proposed method is a general approach which can be used to synthesize the optimal designs of compliant mechanisms with better computational efficiency.

scholarly journals Design and Experiment Using Flexible Bumps for Piezoelectric-Driven Hydraulically Amplified Braille Dot Display

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 795
Author(s):  
Xiaochao Tian ◽  
Yuze Sun ◽  
Zhiyao Li ◽  
Hu Wang ◽  
Zhicong Wang ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Water Discharge ◽  
Experimental Tests ◽  
Output Displacement ◽  
Amplification Ratio ◽  
Fluid Resonance ◽  
Piezoelectric Vibrator ◽  
Flexible Film ◽  
Touch Sensitivity ◽  
Sensitivity Standard

This paper describes the design of a piezoelectric-driven hydraulically amplified Braille-flexible bump device that enables the flexible formation of Braille characters. A piezoelectric vibrator is used to excite fluid resonance in a cavity, and displacement is realized by compressing the fluid, allowing Braille character dots to be formed. First, the structural design and working principle of the device, as well as the method used to drive the fluid, are explained. Expressions for the output displacement and amplification ratio of the flexible film and piezoelectric vibrator are then obtained through kinetic analysis of the system unit. Subsequently, the structural parameters that affect the output displacement and the liquid amplification are described. Finally, experimental tests of the system are explained. The results indicate that the output displacement of the contact formed by the flexible film reaches 0.214 mm, satisfying the requirements of the touch sensitivity standard for the blind, when the fluid cavity diameter measures 31 mm and the resonance frequency is 375.4 Hz. The corresponding water discharge is 8.8 mL. This study proves that constructing a Braille bump device in this way is both feasible and effective.

Sign in / Sign up

Export Citation Format

Share Document