In this work, a design platform for the modeling, simulation and optimization of fluidic components and their interactions in larger systems is developed. A hydrogel-based stimulus-sensitive microvalve is the core element of the microfluidic toolbox. Essential material properties as swelling-stimuli functions and the cooperative diffusion are extracted from measurements. The results provide necessary input data for finite element simulations in order to extract characteristic properties of the mechanical and fluid domains. Finally, the behavior of the microvalve and other fluidic library elements is implemented in Matlab Simscape for component and system simulations. Case studies and design optimization can be realized in a very short time with high accuracy. The toolbox is suitable for research and development and as software for academic education. The library elements are evaluated for a chemofluidic NAND gate, a chemofluidic decoder and a chemofluidic oscillator.:1 Introduction to Microfluidic Systems
1.1 Chemofluidic Enables Scalable and Logical Microfluidics
1.2 Focus of this Work
2 Fundamentals for Hydrogel-based Lab-on-Chip Systems
2.1 Basic Hydrogel Material Behavior
2.1.1 Basic Swelling Behavior
2.1.2 General Properties of Hydrogels
2.2 Overview of the used Microtechnology
2.2.1 Synthesis of P(NIPAAm-co-SA)
2.2.2 Microfabrication of a Microfluidic Chip
2.3 Introduction to Modeling and Simulation Techniques
2.3.1 Computer-aided Design Methodologies
2.3.2 Model Abstraction Levels for Computer-Aided Design
2.3.3 Modeling Techniques for Microvalves in a Fluidic System
3 Analytical Descriptions of Swelling
3.1 Quasi-Static Description
3.1.1 Physical Static Chemo-Thermal Description
3.1.2 Finite Element Routine for Static Thermo-Elastic Expansion
3.1.3 Static System Level Design for Hydrogel Swelling
3.2 Transient Description
3.2.1 Physical Dynamic Chemo-Thermal Description
3.2.2 Finite Element Routine for Dynamic Thermo-Elastic Expansion
3.2.3 Transient System Level Design for Hydrogel Swelling
3.3 Swelling Hysteresis Effect
3.3.1 Quasi-static Hysteresis
3.3.2 Transient Hysteresis
4 Characterization of Hydrogel
4.1 Data Acquisition through Automated Measurements
4.1.1 Measuring the Swelling of Hydrogels
4.1.2 Contactless Measurement Concept to Determine the Core Stiffness of Hydrogels
4.2 Data Evaluation with Image Recognition
4.3 Data Fitting and Model Adaption
4.3.1 Quasi-static Response
4.3.2 Transient Response
4.3.3 Hysteresis Response
5 Modeling Swelling in Finite Elements
5.1 Validity of the Model and Simulation Approach
5.2 Thermo-Mechanical Model of the Hydrogel Expansion Behavior
5.2.1 Change of the Length by Thermal Expansion
5.2.2 Stress-Strain Relationship for Hydrogels
5.2.3 Thermal Volume Expansion and Parameter Adaptation
5.2.4 Heat Transfer Coefficient
5.3 Volume Phase-Transition of a Hydrogel implemented in ANSYS
5.4 Computational Fluid Dynamics
5.4.1 Analytic Mesh Morphing
5.4.2 One-way Fluid Structure Interaction Modeling
5.4.3 Towards a Two-way Fluid Structure Interaction Model in CFX
6 Lumped Modeling
6.1 The Chemical Volume Phase-transition Transistor Model
6.1.1 Static Hysteresis
6.1.2 Equilibrium Swelling Length – Quasi-static Behavior
6.1.3 Kinematic Swelling Length - Transient Behavior
6.1.4 Stiffness and Maximum Closing Pressure
6.1.5 Calculation of the Fluidic Conductance
6.1.6 Modeling of the Fluid Flow through the Valve
6.2 Circuit Descriptions Analogy for Microfluidic Applications
6.2.1 Advantages and Limitations of Combined Simulink-Simscape Models
6.2.2 Requirements for Microfluidic Circuits
6.2.3 Graphical User Interfaces and Library Element Management
6.3 Modeling Techniques for the Chemical Volume Phase-transition Transistor (CVPT)
6.3.1 Network Description of CVPT
6.3.2 Signal Flow Description of CVPT
6.3.3 Mixed Signal Flow and Network Model for CVPT
7 Micro-Fluidic Toolbox
7.1 Microfluidic Components
7.1.1 Fluid Sources and Stimuli Sources
7.1.2 Fluidic Resistor with Bidirectional Stimulus Transport
7.1.3 Junctions
7.1.4 Chemical Volume Phase-transition Transistor
7.2 Microfluidic Matlab Toolbox
7.3 Modeling Chemofluidic Logic Circuits
7.3.1 Chemofluidic NAND Gate
7.3.2 Chemofluidic Decoder Application
7.3.3 Chemo-Fluidic Oscillator
7.4 Layout Synthesis
8 Summary and Outlook
Appendix
A 2D Thermo-Mechanical Solid Element for the Finite Element Method
B Thermal Expansion Equation for ANSYS
C Linear Regression of the Thermal Expansion Equation for ANSYS
D Comparing different Mechanical Strain Definitions
E Supporting Documents
E.1 Analytic Static Swelling
E.2 FEM - Matrix Method
E.3 8 Node Finite Element Routine
E.4 FEM - Script to create the CTEX table data
E.5 Comparison of Solid Mechanics / In dieser Arbeit wird eine Entwurfsplattform für die Modellierung, Simulation und Optimierung von fluidischen Komponenten und deren Wechselwirkungen in größeren Systemen entwickelt. Ein Mikroventil auf der Basis von stimuli-sensitiven Hydrogelen ist das Kernelement des Entwurfstools. Wesentliche Materialeigenschaften wie das Quellverhalten und der kooperative Diffusionskoeffizient werden zu Beginn mit Messungen ermittelt. Mit Finite-Elemente-Simulationen werden aus diesen Daten charakteristische Kennwerte für das mechanische und fluidische Verhalten bestimmt. Sie bilden die Basis für komplexe Systemmodelle in Matlab Simscape, welche das Mikroventil und weitere fluidische Grundelemente in ihrem Zusammenwirken beschreiben. Verschiedene Konzepte können in kurzer Zeit und mit hoher Genauigkeit analysiert, optimiert und verglichen werden. Die Toolbox eignet sich für die Forschung und Entwicklung sowie als Software für die akademische Ausbildung. Sie wurde für den Entwurf eines chemofluidischen NAND-Gatters, für einen chemofluidischen Decoder und für einen chemofluidischen Oszillator eingesetzt.:1 Introduction to Microfluidic Systems
1.1 Chemofluidic Enables Scalable and Logical Microfluidics
1.2 Focus of this Work
2 Fundamentals for Hydrogel-based Lab-on-Chip Systems
2.1 Basic Hydrogel Material Behavior
2.1.1 Basic Swelling Behavior
2.1.2 General Properties of Hydrogels
2.2 Overview of the used Microtechnology
2.2.1 Synthesis of P(NIPAAm-co-SA)
2.2.2 Microfabrication of a Microfluidic Chip
2.3 Introduction to Modeling and Simulation Techniques
2.3.1 Computer-aided Design Methodologies
2.3.2 Model Abstraction Levels for Computer-Aided Design
2.3.3 Modeling Techniques for Microvalves in a Fluidic System
3 Analytical Descriptions of Swelling
3.1 Quasi-Static Description
3.1.1 Physical Static Chemo-Thermal Description
3.1.2 Finite Element Routine for Static Thermo-Elastic Expansion
3.1.3 Static System Level Design for Hydrogel Swelling
3.2 Transient Description
3.2.1 Physical Dynamic Chemo-Thermal Description
3.2.2 Finite Element Routine for Dynamic Thermo-Elastic Expansion
3.2.3 Transient System Level Design for Hydrogel Swelling
3.3 Swelling Hysteresis Effect
3.3.1 Quasi-static Hysteresis
3.3.2 Transient Hysteresis
4 Characterization of Hydrogel
4.1 Data Acquisition through Automated Measurements
4.1.1 Measuring the Swelling of Hydrogels
4.1.2 Contactless Measurement Concept to Determine the Core Stiffness of Hydrogels
4.2 Data Evaluation with Image Recognition
4.3 Data Fitting and Model Adaption
4.3.1 Quasi-static Response
4.3.2 Transient Response
4.3.3 Hysteresis Response
5 Modeling Swelling in Finite Elements
5.1 Validity of the Model and Simulation Approach
5.2 Thermo-Mechanical Model of the Hydrogel Expansion Behavior
5.2.1 Change of the Length by Thermal Expansion
5.2.2 Stress-Strain Relationship for Hydrogels
5.2.3 Thermal Volume Expansion and Parameter Adaptation
5.2.4 Heat Transfer Coefficient
5.3 Volume Phase-Transition of a Hydrogel implemented in ANSYS
5.4 Computational Fluid Dynamics
5.4.1 Analytic Mesh Morphing
5.4.2 One-way Fluid Structure Interaction Modeling
5.4.3 Towards a Two-way Fluid Structure Interaction Model in CFX
6 Lumped Modeling
6.1 The Chemical Volume Phase-transition Transistor Model
6.1.1 Static Hysteresis
6.1.2 Equilibrium Swelling Length – Quasi-static Behavior
6.1.3 Kinematic Swelling Length - Transient Behavior
6.1.4 Stiffness and Maximum Closing Pressure
6.1.5 Calculation of the Fluidic Conductance
6.1.6 Modeling of the Fluid Flow through the Valve
6.2 Circuit Descriptions Analogy for Microfluidic Applications
6.2.1 Advantages and Limitations of Combined Simulink-Simscape Models
6.2.2 Requirements for Microfluidic Circuits
6.2.3 Graphical User Interfaces and Library Element Management
6.3 Modeling Techniques for the Chemical Volume Phase-transition Transistor (CVPT)
6.3.1 Network Description of CVPT
6.3.2 Signal Flow Description of CVPT
6.3.3 Mixed Signal Flow and Network Model for CVPT
7 Micro-Fluidic Toolbox
7.1 Microfluidic Components
7.1.1 Fluid Sources and Stimuli Sources
7.1.2 Fluidic Resistor with Bidirectional Stimulus Transport
7.1.3 Junctions
7.1.4 Chemical Volume Phase-transition Transistor
7.2 Microfluidic Matlab Toolbox
7.3 Modeling Chemofluidic Logic Circuits
7.3.1 Chemofluidic NAND Gate
7.3.2 Chemofluidic Decoder Application
7.3.3 Chemo-Fluidic Oscillator
7.4 Layout Synthesis
8 Summary and Outlook
Appendix
A 2D Thermo-Mechanical Solid Element for the Finite Element Method
B Thermal Expansion Equation for ANSYS
C Linear Regression of the Thermal Expansion Equation for ANSYS
D Comparing different Mechanical Strain Definitions
E Supporting Documents
E.1 Analytic Static Swelling
E.2 FEM - Matrix Method
E.3 8 Node Finite Element Routine
E.4 FEM - Script to create the CTEX table data
E.5 Comparison of Solid Mechanics
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:74058 |
| Date | 26 February 2021 |
| Creators | Mehner, Philipp Jan |
| Contributors | Richter, Andreas, Wallmersperger, Thomas, Technische Universität Dresden |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | info:eu-repo/grantAgreement/Deutsche Forschungsgemeinschaft/Graduiertenkolleg/211944370//Hydrogel-Basierte Mikrosysteme/GRK 1865 |
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