Design and microfabrication of a compliant microgripper using nonbrittle and biocompatible material

2013 ◽  
Vol 227 (12) ◽  
pp. 2886-2896 ◽  
Author(s):  
F Barazandeh ◽  
S NazariNejad ◽  
RDB Nadafi ◽  
A Moobed MehdiAbadi ◽  
Z Ghasemi
Keyword(s):  
Biomedical Applications ◽  
Fabrication Method ◽  
Element Analysis ◽  
Fabrication Cost ◽  
Proper Size ◽  
Wide Range ◽  
The Finite Element Analysis ◽  
Genetic Algorithm Method ◽  
Artificial Fertilization ◽  
Silicon Based

This article presents the design and fabrication of a monolithic compliant microgripper. This research has mostly focused on the process of design, the finite element analysis, the fabrication method and use of a genetic algorithm method to solve the nonlinear kinematic equations and estimate the proper dimensions of the design. This new architecture of the microgripper enables it to apply a variable force to a wide range of micro-objects handled in microassembly, micromanipulation and also in biomedical applications such as artificial fertilization. The microgripper was designed to be normally open. Two shape memory alloy actuators close the jaws. To achieve the tasks, the most proper size has been considered to be 8 × 8 mm, with thickness of 250 µm. Polyethylene terephthalate has been used as the structural material. It is not brittle and is less sensitive to shock compared with silicon-based grippers; furthermore, its fabrication cost is less and it does not lose precision.

Application of subloading-overstress friction model to finite element analysis

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
T. Kuwayama ◽  
K. Hashiguchi ◽  
N. Suzuki ◽  
N. Yoshinaga ◽  
S. Ogawa
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Flat Surface ◽  
Surface Friction ◽  
Friction Model ◽  
Sliding Velocity ◽  
Element Analysis ◽  
Contact Behaviour ◽  
Wide Range ◽  
The Finite Element Analysis

Accurate prediction of contact behaviour between machine tools and metals is required for the mechanical design of machinery. In this article, the numerical analysis of the contact behaviour is described by incorporating the subloading-overstress model [6] which is capable of describing the contact behaviour for a wide range of sliding velocity including the increase of coefficient of friction with the increase of sliding velocity. And its validity is verified by the comparison with some test results. First, in order to examine the influence of sliding velocities on the friction properties, the flat-surface friction tests for lubricated interfaces between galvannealed steel sheet and SKD-11 tool steel were performed. As a result, It is observed that the friction smoothly translate to kinetic friction, after exhibiting the peak at the static friction. In addition, it is observed that the higher the sliding velocity, the larger the friction resistance, meaning the positive rate sensitivity. Then the subloading-overstress model is implemented in the finite element analysis program ABAQUS/Standard, and it is used to simulate the flat-surface friction tests. The predictions from the finite element analysis are shown to be in very good agreement with experimental results.

scholarly journals Sensing the Torque in a Robot’s Joints

1998 ◽  
Vol 120 (09) ◽  
pp. 66-69 ◽  
Author(s):  
Farhad Aghili ◽  
Martin Buehler ◽  
John M. Hollerbach
Keyword(s):  
High Stress ◽  
High Sensitivity ◽  
Design Criterion ◽  
Sensor Design ◽  
Direct Drive ◽  
Element Analysis ◽  
Proper Size ◽  
The Finite Element Analysis ◽  
Final Design ◽  
Thrust Forces

This article describes design specifications of a new sensor that can accurately measure the torsion moment in a direct-drive robot, even in the presence of strong overhang, thrust forces, and bending moments. Introducing a torque sensor into a robot joint adds flexibility. Although torsional flexibility can be compensated for by sophisticated controllers, deflection in the other axes is more problematic. Consequently, another design criterion dictates high stiffness in non-torsional directions. The sensor design must optimize, and trade off among several conflicting design criteria. Also, many design iterations are required to arrive at a final design. Despite this complexity, it is possible to arrive at a novel basic sensor design. Thin-section rectangular bars experience high stress/ strain concentrations under torsion loads, which yield high sensitivity without sacrificing stiffness. This fact suggests that an appropriate structure should be primarily stressed by torsion. The team used the finite element analysis (FEA) capabilities of I-DEAS from Structural Dynamics Research Corp. to finalize the dimensions so that performance would be optimized. FEA was also used to select the location and proper size of the strain gauges.

scholarly journals Fabricating Silicon Resonators for Analysing Biological Samples

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1546
Author(s):  
Momoko Kumemura ◽  
Deniz Pekin ◽  
Vivek Anand Menon ◽  
Isabelle Van Van Seuningen ◽  
Dominique Collard ◽  
...  
Keyword(s):  
Double Layer ◽  
Biological Samples ◽  
Electrical Double Layer ◽  
Biomedical Applications ◽  
Microelectromechanical Systems ◽  
Layer Formation ◽  
Wide Range ◽  
Experimental Approaches ◽  
Silicon Based ◽  
Microelectromechanical Resonators

The adaptability of microscale devices allows microtechnologies to be used for a wide range of applications. Biology and medicine are among those fields that, in recent decades, have applied microtechnologies to achieve new and improved functionality. However, despite their ability to achieve assay sensitivities that rival or exceed conventional standards, silicon-based microelectromechanical systems remain underutilised for biological and biomedical applications. Although microelectromechanical resonators and actuators do not always exhibit optimal performance in liquid due to electrical double layer formation and high damping, these issues have been solved with some innovative fabrication processes or alternative experimental approaches. This paper focuses on several examples of silicon-based resonating devices with a brief look at their fundamental sensing elements and key fabrication steps, as well as current and potential biological/biomedical applications.

Improvement of the Frontal Structure of a Bus for Crash Accidents

2012 ◽  
Author(s):  
P. D. Jeyakumar ◽  
G. Devaradjane
Keyword(s):  
Geometric Modeling ◽  
The Body ◽  
Side Impact ◽  
Element Analysis ◽  
Power Train ◽  
Frontal Crash ◽  
Wide Range ◽  
The Finite Element Analysis ◽  
Body In White ◽  
Bus Structure

The increasing legal and customer demands on passive safety of automobiles have to be fulfilled under the conditions of shortened development times and cost reductions. Today the design process of a bus with regard to its crashworthiness function is driven by a virtual development. A wide range of different applications has to be covered by simulation influencing the design of body-in-white, interior and exterior trim, chassis and power train. In recent days more emphasis has been given to Passenger bus rollover analysis and side impact but the study of frontal impact behaviour of the passenger bus is ignored. The finite element analysis is used for estimating the damage of the passenger bus due to the frontal crash. The vehicle model is allowed to frontal crash with rigid material. The deformation and displacement characteristics of the structure are analyzed at different speeds. Geometric modeling of the bus structure has been created by using CATIA cad package and discritized by ANSYS LS-Dyna. The numerical simulation is carried out for different velocities of bus structure. The results of displacement during collision are plotted on the graph. Some improvements were suggested in the body structure after analysing different types of crack initiators.

Analysis of Sectional Girder Flexion Calculate of Tapered Canal Bi-Material

2015 ◽  
Vol 1088 ◽  
pp. 838-842
Author(s):  
Li Na Chen ◽  
Zhi Li ◽  
Li Qing Qin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Corrosion Resistance ◽  
Fibrous Composite ◽  
Calculation Formula ◽  
Deflection Curve ◽  
Element Analysis ◽  
Structural Style ◽  
Wide Range ◽  
The Finite Element Analysis

There is a wide range of the application of metal conical pipe, but the corrosion resistance of a single metal material is poor, this paper designed a Bi material of conical pipe that use metal and fibrous composite. To derive the calculation formula of deflection curve of its structural style, to verify the results. combined with the finite element analysis.

Sandwich Panels Made of Perforated Metal Materials

2021 ◽  
Vol 320 ◽  
pp. 155-160
Author(s):  
Viktor Mironov ◽  
Mihails Lisicins ◽  
Irina Boiko
Keyword(s):  
Experimental Studies ◽  
Sandwich Panels ◽  
Skin Layer ◽  
Core Material ◽  
Metallic Materials ◽  
Element Analysis ◽  
Metallic Material ◽  
Wide Range ◽  
The Finite Element Analysis ◽  
Metallic Sheet

Nowadays, the growing attention has focused on the sandwich-structured composites (panels), especially on those, which are environmentally friendly. The sandwich panel is a special type of the composites made of at least three layers: a core and a skin-layer bonded to each side. The aim of this paper is to investigate the possibility of using of perforated metallic materials for producing sandwich panels for the different application in the civil engineering. By using the perforated metallic materials in combination with different core materials or by using the perforated metallic material as the core material the wide range of products for the construction, damping or isolation purposes could be manufactured. In the paper the example of using of perforated metallic sheet materials for manufacturing the sandwich panels is proposed. Both, the simulation and experimental studies (mechanical testing) were carried out in order to assess the load-bearing capacity of sandwich panels and to prove the applicability of the proposed sandwich panels for construction structures. For the analysis of the achieved structures the finite element analysis (FEA) software was used. The simulation results are well-coincided with the results of the experimental studies. Thus, new types of the sandwich panels and the manufacturing technology thereof are shown its reliability and could be recommended for application in the different branches, in particular for producing lightweight ceiling panels with filler from heat insulating materials.

Three Dimensional Analysis of Combined Forward and Backward Extrusion-Forging Process Using DEFORM 3D

2014 ◽  
Vol 592-594 ◽  
pp. 791-795 ◽  
Author(s):  
Srikar Potnuru ◽  
Raviteja Vinjamuri ◽  
Susant Kumar Sahoo ◽  
Santosh Kumar Sahoo
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Element Analysis ◽  
Forging Process ◽  
Forming Load ◽  
Backward Extrusion ◽  
Wide Range ◽  
The Finite Element Analysis ◽  
3D Software ◽  
Deform 3D

Combined extrusion-forging is used in the manufacturing of a wide range of engineering components. Due to the complexity of the forming process and because of so many process variables, it is difficult to predict the forming load required to manufacture a given component. It is very costly to conduct different trail runs to know the metal flow patterns, and for redesigning of tool and die setup, etc. The present paper deals with the Finite element analysis of combined forward and backward extrusion-forging process for the product shape socket wrench. Two types of socket wrenches, Square-square type and hexagon-square type have been taken for the present analysis. The modelling has been done by using 3D modelling software CATIA and simulation through the Finite element based package DEFORM 3D software. The forming load can be estimated by the results obtained from the Finite element analysis through DEFORM 3D software.

A two degrees of freedom comb capacitive-type accelerometer with low cross-axis sensitivity

2019 ◽  
Vol 13 (3) ◽  
pp. 5334-5346
Author(s):  
M. N. Nguyen ◽  
L. Q. Nguyen ◽  
H. M. Chu ◽  
H. N. Vu
Keyword(s):  
Degrees Of Freedom ◽  
Proof Mass ◽  
Vibration Modes ◽  
Electrode Structure ◽  
Element Analysis ◽  
Mechanical Coupling ◽  
Fully Differential ◽  
Mode Effects ◽  
The Finite Element Analysis ◽  
Cross Axis

In this paper, we report on a SOI-based comb capacitive-type accelerometer that senses acceleration in two lateral directions. The structure of the accelerometer was designed using a proof mass connected by four folded-beam springs, which are compliant to inertial displacement causing by attached acceleration in the two lateral directions. At the same time, the folded-beam springs enabled to suppress cross-talk causing by mechanical coupling from parasitic vibration modes. The differential capacitor sense structure was employed to eliminate common mode effects. The design of gap between comb fingers was also analyzed to find an optimally sensing comb electrode structure. The design of the accelerometer was carried out using the finite element analysis. The fabrication of the device was based on SOI-micromachining. The characteristics of the accelerometer have been investigated by a fully differential capacitive bridge interface using a sub-fF switched-capacitor integrator circuit. The sensitivities of the accelerometer in the two lateral directions were determined to be 6 and 5.5 fF/g, respectively. The cross-axis sensitivities of the accelerometer were less than 5%, which shows that the accelerometer can be used for measuring precisely acceleration in the two lateral directions. The accelerometer operates linearly in the range of investigated acceleration from 0 to 4g. The proposed accelerometer is expected for low-g applications.

Tread Depth Effects on Tire Rolling Resistance

2001 ◽  
Vol 29 (3) ◽  
pp. 134-154 ◽  
Author(s):  
J. R. Luchini ◽  
M. M. Motil ◽  
W. V. Mars
Keyword(s):  
Finite Element Analysis ◽  
Common Knowledge ◽  
Rolling Resistance ◽  
Test Method ◽  
Tire Model ◽  
Element Analysis ◽  
Truck Tires ◽  
The Finite Element Analysis ◽  
Equilibrium Test ◽  
Depth Effects

Abstract This paper discusses the measurement and modeling of tire rolling resistance for a group of radial medium truck tires. The tires were subjected to tread depth modifications by “buffing” the tread surface. The experimental work used the equilibrium test method of SAE J-1269. The finite element analysis (FEA) tire model for tire rolling resistance has been previously presented. The results of the testing showed changes in rolling resistance as a function of tread depth that were inconsistent between tires. Several observations were also inconsistent with published information and common knowledge. Several mechanisms were proposed to explain the results. Additional experiments and models were used to evaluate the mechanisms. Mechanisms that were examined included tire age, surface texture, and tire shape. An explanation based on buffed tread radius, and the resulting changes in footprint stresses, is proposed that explains the observed experimental changes in rolling resistance with tread depth.

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