Lambert Capillary Forces in Microassembly

Modeling, Simulation, Experiments, and Case Study
1. Auflage 2007
ISBN: 978-0-387-71089-1
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 263 Seiten

Reihe: Microtechnology and MEMS

Capillary Forces in Microassembly discusses the use of capillary forces as a gripping principle in microscale assembly. Clearly written and well-organized, this text brings together physical concepts at the microscale with practical applications in micromanipulation. Throughout this work, the reader will find a review of the existing gripping principles, elements to model capillary forces as well as descriptions of the simulation and experimental test bench developed to study the design parameters.  Using well-known concepts from surface science (such as surface tension, capillary effects, wettability, and contact angles) as inputs to mechanical models, the amount of effort required to handle micro-components is then predicted. Researchers and engineers involved in micromanipulation and precision assembly will find this a highly useful reference for microassembly system design and analysis.

Autoren/Hrsg.

Lambert, Pierre

Inhaltsverzeichnis

1;Foreword;7
2;Preface;9
2.1;0.1 Context;9
2.2;0.2 Contributions of this Book;12
2.3;0.3 What this Book Does Not Tell;15
2.4;0.4 Reading Suggestion;16
3;Contents;17
4;Part I Microassembly Specificities;23
4.1;1 From Conventional Assembly to Microassembly;24
4.1.1;1.1 Introduction;24
4.1.2;1.2 Design of Monolithic Products for Microassembly;25
4.1.3;1.3 Combined Part Manufacturing and Assembly;27
4.1.4;1.4 Product External Assembly Functions;27
4.1.5;1.5 Product Internal Assembly Functions;27
4.1.6;1.6 Stochastic or Self-Assembly;28
4.1.7;1.7 Parallel Assembly;29
4.1.8;1.8 Conclusions;29
4.2;2 Classification of Forces Acting in the Microworld;30
4.2.1;2.1 Introduction;30
4.2.2;2.2 Classification Schemes of the Forces;31
4.2.3;2.3 Conclusions;33
4.3;3 Handling Principles for Microassembly;34
4.3.1;3.1 Introduction;34
4.3.2;3.2 Presentation of Gripping Principles;34
4.3.3;3.3 Classification of Gripping Principles;46
4.3.4;3.4 Comparison between Gripping Principles;49
4.3.5;3.5 Conclusions;50
4.4;4 Conclusions;55
5;Part II Modeling and Simulation of Capillary Forces;56
5.1;5 Introduction;57
5.2;6 First Set of Parameters;58
5.2.1;6.1 Introduction;58
5.2.2;6.2 Surface Tension;58
5.2.3;6.3 Young–Dupr ´ e Equation and Static Contact Angle;59
5.2.4;6.4 Laplace Equation;60
5.2.5;6.5 Effects of a Liquid Bridge on the Adhesion Between Two Solids;62
5.2.6;6.6 A Priori Justification of a Capillary Gripper;64
5.2.7;6.7 Conclusions;66
5.3;7 State of the Art on the Capillary Force Models at Equilibrium;67
5.3.1;7.1 Introduction;67
5.3.2;7.2 Energetic Approach: Interaction Between Two Parallel Plates;67
5.3.3;7.3 Energetic Approach: Other Configurations;71
5.3.4;7.4 Geometrical Approach: Circle Approximation;73
5.3.5;7.5 Geometrical Approach: Parabolic Approximation;77
5.3.6;7.6 Comparisons and Summary;77
5.4;8 Static Simulation at Constant Volume of Liquid;80
5.4.1;8.1 Introduction;80
5.4.2;8.2 Description of the Problem;80
5.4.3;8.3 Assumptions;81
5.4.4;8.4 Equations and Numerical Simulation;82
5.4.5;8.5 Discussion and Conclusions;86
5.5;9 Comparisons Between the Capillary Force Models;88
5.5.1;9.1 Introduction;88
5.5.2;9.2 Qualitative Arguments;88
5.5.3;9.3 Analytical Arguments;90
5.5.4;9.4 Conclusions;96
5.6;10 Example 1: Application to the Modeling of a Microgripper for Watch Bearings;97
5.6.1;10.1 Introduction;97
5.6.2;10.2 Presentation of the Case Study;97
5.6.3;10.3 Analytical Model Based on the Circle Approximation;100
5.6.4;10.4 Numerical Model Based on the Laplace Equation;103
5.6.5;10.5 Benchmark;107
5.6.6;10.6 Pressure Difference Saturation;108
5.6.7;10.7 Conclusions;110
5.7;11 Second Set of Parameters;111
5.7.1;11.1 Introduction;111
5.7.2;11.2 Surface Heterogeneities and Surface Impurities;111
5.7.3;11.3 Surface Roughness;112
5.7.4;11.4 Static Contact Angle Hysteresis;113
5.7.5;11.5 Dynamic Spreading;114
5.7.6;11.6 Conclusions;115
5.8;12 Limits of the Static Simulation;116
5.8.1;12.1 Introduction;116
5.8.2;12.2 Performances of the Assembly Machines;116
5.8.3;12.3 Nondimensional Numbers and Buckingham p Theorem;116
5.8.4;12.4 Another Approach: Use of a 1D Analytical Model;119
5.8.5;12.5 Limitations of the Static Model;121
5.8.6;12.6 Conclusions;123
5.9;13 Approaching Contact Distance, Rupture Criteria, and Volume Repartition After Separation;124
5.9.1;13.1 Introduction;124
5.9.2;13.2 Approaching Contact Distance;124
5.9.3;13.3 Rupture Distance and Residual Volume of Liquid;126
5.9.4;13.4 Mathematical and Notation Preliminaries;127
5.9.5;13.5 Volume Repartition;128
5.9.6;13.6 Rupture Condition and Rupture Gap;130
5.9.7;13.7 Analytical Benchmarks;132
5.9.8;13.8 Summary of the Methods;133
5.9.9;13.9 Comparison between the Methods;135
5.9.10;13.10 Conclusions;137
5.10;14 Example 2: Numerical Implementation of the Proposed Models;139
5.10.1;14.1 Introduction;139
5.10.2;14.2 Liquid Bridge Simulation for the Analysis of a Meniscus;139
5.10.3;14.3 Evaluation of the Double Iterative Scheme;143
5.10.4;14.4 Pseudodynamic Simulation;145
5.10.5;14.5 Conclusions;147
5.11;15 Conclusions of the Theoretical Study of Capillary Forces;148
6;Part III Experimental Aspects;150
6.1;16 Introduction;151
6.2;17 Test Bed and Characterization;153
6.2.1;17.1 Introduction;153
6.2.2;17.2 Requirements;153
6.2.3;17.3 Test Bed Principles;155
6.2.4;17.4 CAD Model and Drawings;158
6.2.5;17.5 Characteristics of the Force Measurement Set Up;161
6.2.6;17.6 Characteristics of the Contact Angles Measurements;164
6.2.7;17.7 Surface Tension Measurement;165
6.2.8;17.8 Modus Operandi;165
6.2.9;17.9 Characterization;168
6.2.10;17.10 Conclusions;172
6.3;18 Results;173
6.3.1;18.1 Introduction;173
6.3.2;18.2 Preliminary Results: Validation of the Simulation Code;173
6.3.3;18.3 Advancing vs Receding Contact Angle;178
6.3.4;18.4 Influence of the Gap;180
6.3.5;18.5 Influence of the Gripper Geometry;181
6.3.6;18.6 Influence of the Surface Tension;182
6.3.7;18.7 Influence of the Contact Angle .1;184
6.3.8;18.8 Influence of the Relative Orientation;184
6.3.9;18.9 Auxiliary PTFE Tip;186
6.3.10;18.10 Dynamical Release;187
6.3.11;18.11 Approaching Contact and Rupture Distances;195
6.3.12;18.12 Shear Force;196
6.3.13;18.13 Conclusions;197
6.4;19 Example 3: Application to the Watch Bearing Case Study: Characterization;198
6.4.1;19.1 Introduction;198
6.4.2;19.2 Available Grippers;198
6.4.3;19.3 Available Components;200
6.4.4;19.4 Liquid Properties;200
6.4.5;19.5 Liquid Dispensing;201
6.4.6;19.6 Contact Angles;204
6.5;20 Example 4: Application to the Watch Bearing Case Study: Results;207
6.5.1;20.1 Introduction;207
6.5.2;20.2 Picking;207
6.5.3;20.3 Placing;212
6.5.4;20.4 Compliance Effect;213
6.5.5;20.5 Force Measurement;214
6.5.6;20.6 Conclusions;217
6.6;21 Conclusions;219
6.6.1;21.1 Introduction;219
6.6.2;21.2 Picking Operations;219
6.6.3;21.3 Releasing Strategies;221
6.6.4;21.4 Design Aspects;223
7;Part IV General Conclusions and Perspectives;227
7.1;22 Conclusions and Perspectives;228
7.1.1;22.1 Conclusions;228
7.1.2;22.2 Perspectives;230
8;Part V Appendices;231
8.1;A Modeling Complements;232
8.1.1;A.1 Analytical Approximations of the Capillary Forces;232
8.1.2;A.2 Volume Repartition by the Energetic Approach;238
8.2;B Geometry Complements;242
8.2.1;B.1 Area and Volume of a Spherical Cap;242
8.2.2;B.2 Differential Geometry of Surfaces;243
8.2.3;B.3 Catenary Curve;245
8.3;C Comparison Between Both Approaches;247
8.4;D Symbols;251
9;References;254
10;Index;264