Gerlach / Arndt Hydrogel Sensors and Actuators

Engineering and Technology
1. Auflage 2009
ISBN: 978-3-540-75645-3
Verlag: Springer Berlin Heidelberg
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, Band 6, 272 Seiten

Reihe: Springer Series on Chemical Sensors and Biosensors

Hydrogels are a fascinating class of polymers which show an immense ability of swelling under the influence of temperature, pH value or concentrations of different species in aqueous solutions. The volume change can amount up to several hundred percent. This unique behaviour is already used in such applications like disposable diapers, contact lenses or drug-delivery systems.

The ability to perform mechanical work has been shifted the technical interest more and more towards sensors and actuators exploiting the thermo-chemo-mechano-electrical coupling within hydrogels. The accuracy requirements for such devices are much more demanding than for previous applications. Therefore, a deep knowledge of both the material and the functional properties of hydrogel sensors and actuators is needed. The monograph describes state of the art and recent developments for these materials in sensor and actuator technology.

Autoren/Hrsg.

Gerlach, Gerald

Arndt, K. -F.

Inhaltsverzeichnis

1;152490_1_En_FM1_OnlinePDF.pdf;2
2;152490_1_En_1_Chapter_OnlinePDF.pdf;11
2.1;Chapter : General Properties of Hydrogels;11
2.1.1;Introduction;12
2.1.2;Swelling and Elasticity of Hydrogels;13
2.1.3;Inhomogeneity of Hydrogels;18
2.1.4;Hydrogels with Improved Properties;20
2.1.5;References;22
3;152490_1_En_2_Chapter_OnlinePDF.pdf;25
3.1;Chapter : Synthesis of Hydrogels;25
3.1.1;Chemical Cross-Linking;29
3.1.1.1;Temperature Dependent Swelling;29
3.1.1.2;pH-Dependent Swelling;32
3.1.1.3;Bi-Responsive Materials;33
3.1.1.4;Polymerisation and Cross-Linking;35
3.1.1.4.1;Effect of Synthesis Temperature;36
3.1.1.4.2;Effect of Solvent;37
3.1.1.4.3;Effect of Cross-Linker Concentration;37
3.1.1.4.4;Effect of Monomer Concentration;37
3.1.1.4.5;Morphological Characterization and Photo Patterning;38
3.1.1.5;Generation of Hydrogel Patterns;38
3.1.2;Cross-Linking and Patterning by Irradiation;41
3.1.2.1;Sol-Gel Analysis;41
3.1.2.2;Radiation Source;44
3.1.2.3;Radiochemical Synthesis of Hydrogels;48
3.1.2.4;Examples of Gel Synthesis;49
3.1.2.5;Patterning;56
3.1.3;Gel Point Determination of the Reversible Gelatin Gelling System;61
3.1.3.1;Gel Point;61
3.1.3.2;Gel Point Determination Methods;62
3.1.3.2.1;Dynamic Light Scattering;62
3.1.3.2.2;Oscillatory shear rheology;63
3.1.3.3;Gelatin as Example for Reversible Gelation;64
3.1.3.3.1;Critical Dynamical Exponents for the Gelation Threshold of Gelatin;65
3.1.4;Conclusions;68
3.1.5;References;71
4;152490_1_En_3_Chapter_OnlinePDF.pdf;78
4.1;Chapter : Swelling-Related Processes in Hydrogels;78
4.1.1;Thermodynamics of Swelling;83
4.1.1.1;Chemical Potential and Equilibrium Degree of Swelling;83
4.1.1.2;Flory-Rehner Theory, Mixing Part;84
4.1.1.3;Flory-Rehner Theory, Elastic Part;84
4.1.1.4;Discussion of Flory-Rehner Equation;92
4.1.1.5;Mechanical Power Generation on Example of PVA-PAAc gel;96
4.1.2;Kinetics of Swelling;97
4.1.2.1;Diffusion;97
4.1.2.2;Cooperative Diffusion Coefficient;99
4.1.2.3;Time Dependence of the Degree of Swelling;101
4.1.2.4;Volume Phase Transition;105
4.1.2.5;Gels with Fast Response;108
4.1.2.6;Determination of Dcoop of Polyelectrolyte Hydrogels by DLS;109
4.1.3;Characterization of Molecular Processes;111
4.1.3.1;Fourier Transform Infrared Spectroscopy and Raman Spectroscopy;111
4.1.3.1.1;3.1.1Introduction;111
4.1.3.1.2;3.1.2Fourier Transform Infrared Spectroscopy;111
4.1.3.1.3;3.1.3Raman Spectroscopy;111
4.1.3.1.4;3.1.4Sample Preparation;111
4.1.3.1.4.1;Sampling Techniques for FT-IR Spectroscopy;88
4.1.3.1.4.2;Deuterium Oxide Instead Water?;111
4.1.3.1.4.3;Sampling Techniques for Raman Spectroscopy;120
4.1.3.1.5;3.1.5Qualitative Spectral Interpretation;111
4.1.3.1.5.1;General Approaches;121
4.1.3.1.5.2;The Region 2,000-3,800cm-1;122
4.1.3.1.5.3;The Region 900-2,000cm-1;122
4.1.3.1.5.4;The Region 500-900cm-1;124
4.1.3.1.6;3.1.6FT-IR and Raman Spectra of Hydrogels;111
4.1.3.1.7;3.1.7FT-IR and Raman spectroscopic imaging;111
4.1.3.1.7.1;FT-IR and Raman Imaging Spectrometer;132
4.1.3.1.7.2;Enhanced Data Analysis and Imaging Evaluation;133
4.1.3.2;NMR Imaging;135
4.1.3.2.1;3.2.1Application on Network Characterization;111
4.1.3.2.2;3.2.2Principle of NMR Imaging;111
4.1.3.2.3;3.2.3Examples;111
4.1.3.2.3.1;Monitoring of Transport Processes;138
4.1.3.2.3.2;Transport Processes for Drug Release;138
4.1.3.2.3.3;Volume Phase Transition of a Temperature Sensitive Hydrogel;139
4.1.3.2.3.4;Diffusion of Small Molecules into a Swollen Hydrogel;139
4.1.3.2.3.5;Distribution of Swelling Agent inside a Swollen Gel;140
4.1.4;References;142
5;152490_1_En_4_Chapter_OnlinePDF.pdf;146
5.1;Chapter : Modelling and Simulation of the Chemo-Electro-Mechanical Behaviour;146
5.1.1;Modelling on Different Scales;150
5.1.1.1;Statistical Theory;151
5.1.1.2;Porous Media Theory;155
5.1.1.3;Coupled Chemo-Electro-Mechanical Model;157
5.1.1.3.1;Chemical Field;158
5.1.1.3.2;Electrical Field;158
5.1.1.3.3;Mechanical Field;159
5.1.1.3.4;Coupling of the Involved Fields;159
5.1.1.4;Discrete Element Model;161
5.1.2;Coupled Chemo-Electro-Mechanical Model;162
5.1.2.1;Discretisation;162
5.1.2.2;Coupling Schemes;163
5.1.2.3;Numerical Simulation of the Chemo-Electrical Field;164
5.1.2.3.1;Chemical Stimulation;165
5.1.2.3.2;Electrical Stimulation;166
5.1.2.4;Numerical Simulation of the Chemo-Electro-Mechanical Field;167
5.1.2.4.1;Chemical Stimulation;167
5.1.2.4.2;Electrical Stimulation;168
5.1.2.4.3;Mechanical Stimulation;168
5.1.3;Comparison with Experimental Results;169
5.1.4;Conclusions and Outlook;170
5.1.5;References;171
6;152490_1_En_5_Chapter_OnlinePDF.pdf;173
6.1;Chapter : Hydrogels for Chemical Sensors;173
6.1.1;Hydrogel-Based Piezoresistive Chemical Sensors;176
6.1.1.1;Operational Principle;176
6.1.1.2;Sensor Design;177
6.1.1.3;Sensor Calibration;178
6.1.2;Hydrogel Material Preparation and Characterization;179
6.1.2.1;Thermally Cross-Linked Poly(vinyl Alcohol)/Poly(Acrylic Acid) Blend;180
6.1.2.2;Chemically Cross-Linked N-Isopropylacrylamide;180
6.1.2.3;Photo Cross-Linkable Copolymers;181
6.1.2.3.1;Materials;181
6.1.2.3.2;P2VP-block-P(NIPAAm-co-DMIAAm) block copolymer;181
6.1.2.3.3; PNIPAAm-DMAAm-DMIAAm terpolymer;182
6.1.2.3.4; PDMAEMA-DMIMA copolymer;182
6.1.2.3.5;Polymer characterization;182
6.1.2.3.6;UV Cross-Linking;183
6.1.2.4;Hydrogel Conditioning;183
6.1.2.5;Temperature Sensitivity of PNIPAAm Gels;184
6.1.3;pH Sensors;185
6.1.3.1;Sensitivity;186
6.1.3.2;Response Time;188
6.1.3.3;Signal Reproducibility;190
6.1.4;Sensors for Concentration Measurements in Aqueous Solutions;192
6.1.4.1;Sensors for Organic Solvents;193
6.1.4.2;Sensors for Salt Concentrations;196
6.1.4.3;Sensors for Metal Ions Concentrations;196
6.1.5;Summary;200
6.1.6;References;201
7;152490_1_En_6_Chapter_OnlinePDF.pdf;204
7.1;Chapter : Hydrogels for Biosensors;204
7.1.1;Introduction;206
7.1.2;Biosensor Devices;207
7.1.3;Enzyme Biosensors;208
7.1.4;Immobilization of Enzymes and Whole Cells Via Hydrogel Encapsulation;209
7.1.5;Whole-Cell-Based Hydrogel Biosensors;210
7.1.6;Amperometric Biosensors;212
7.1.7;Redox Polymers;213
7.1.8;Multi-Analyte Monitoring Devices;215
7.1.9;Characterization of the Stability of Entrapped Enzymes;217
7.1.10;Nanocalorimetry;220
7.1.11;Smart Hydrogels for Biosensors;222
7.1.12;Summary;224
7.1.13;References;224
8;152490_1_En_7_Chapter_OnlinePDF.pdf;228
8.1;Chapter : Hydrogels for Actuators;228
8.1.1;Introduction;230
8.1.2;Automatic Microfluidic Systems;231
8.1.2.1;Hydrodynamic Transistors;232
8.1.2.1.1;Directly Acting Hydrogel Component;232
8.1.2.1.2;Hydrogel as Servo Drive;233
8.1.2.1.3;Normally Closed and Normally Open Valves;234
8.1.2.1.4;Mechanical Adjustability of the Regulation Point;235
8.1.2.2;Fluidic Propulsion;236
8.1.2.2.1;Chemostat Pumps;236
8.1.2.2.2;Autonomous Pumps;237
8.1.2.3;Tunable Micro-Lenses;238
8.1.3;Microelectromechanical Microfluidic Systems;239
8.1.3.1;Electrothermic and Optoelectrothermic Interface;240
8.1.3.2;Microvalves;241
8.1.3.3;Micropumps;242
8.1.3.3.1;Diffusion Pumps;242
8.1.3.3.2;Displacement Micropumps;243
8.1.3.4;Hydrodynamic Microtransistors;244
8.1.4;High Resolution Tactile Displays;245
8.1.5;Influence of Material and Phase Transition Phenomena on the Operational Characteristics of Hydrogel Elements;246
8.1.5.1;Effects at the Initialisation of Gel Elements;246
8.1.5.1.1;Conditioning Effect;247
8.1.5.1.2;Softening Effect;247
8.1.5.1.3;Volume Change After Polymerisation;247
8.1.5.2;Phenomena at the Volume Phase Transition of Gels;247
8.1.5.2.1;Intrinsic Shrinkage Barrier Effect;247
8.1.5.2.2;Extrinsic Shrinkage Barrier Effect;248
8.1.5.2.3;Two-Step Mechanism of the Volume Phase Transition;248
8.1.5.2.4;Screening Effect;249
8.1.5.2.5;Material Enrichment Inside the Hydrogel;249
8.1.6;Design and Performance;250
8.1.6.1;Response Time;250
8.1.6.1.1;Effective Diffusion Length;250
8.1.6.1.2;Swelling Agent Supply;250
8.1.6.1.3;Counterforces;251
8.1.6.1.4;Recirculation of Process Media;251
8.1.6.2;Pressure Resistance and Particle Tolerance;251
8.1.7;References;252
9;152490_1_En_8_Chapter_OnlinePDF.pdf;256
9.1;Chapter : Polymer Hydrogels to Enable New Medical Therapies;256
9.1.1;Hydrogels in Biomedical Applications;257
9.1.2;Thermo-Responsive Cell Culture Carriers;259
9.1.3;Biohybrid Cell Scaffolds for In Vivo Tissue Engineering;263
9.1.4;Summary and Perspective;269
9.1.5;References;270
10;152490_1_En_BM2_OnlinePDF.pdf;274
10.1;: Index;274