Soft Actuators (eBook)

Preface 5
Contents 7
Part I: Introduction 11
Chapter 1: Progress and Current Status of Materials and Properties of Soft Actuators 12
1.1 Introduction 12
1.2 Gel Actuators 14
1.2.1 pH-Responsive Gels 14
1.2.2 Salt-Responsive Gels 14
1.2.3 Solvent-Responsive Gels 14
1.2.4 Thermo-Responsive Gels 15
1.2.5 Electro-Responsive Gels 15
1.2.6 Photo-Responsive Gels 18
1.2.7 Magneto-Responsive Gels 19
1.3 Conductive Polymer Actuators 19
1.3.1 Electro-Responsive Conductive Polymers 19
1.3.2 Humidity-Responsive Conductive Polymers 21
1.4 Elastomer Actuators 21
1.4.1 Electro-Responsive Elastomers 21
1.4.2 Photo-Responsive Elastomers 22
1.5 Carbon Nanotube Actuators 22
1.6 Bio-Actuators 23
References 23
Chapter 2: Current Status of Applications and Markets of Soft Actuators 28
2.1 Introduction 28
2.2 Current Status of Applications of Soft Actuators 29
2.2.1 Groundbreaking Studies 29
2.2.2 Current Status of Technology of EAP Actuators for Applications 30
2.2.3 Consumer Electronics 30
2.2.4 Biomedical Devices 34
2.2.5 Robotics 34
2.2.6 Other Applications of Soft Actuators 37
2.2.7 Energy Harvesting and Sensor 37
2.3 Current and Expected Markets for Soft Actuators 39
2.4 Conclusion 42
References 44
Part II: Materials of Soft Actuators: Thermo-Driven Soft Actuators 45
Chapter 3: Electromagnetic Heating 46
3.1 Introduction 46
3.2 Surface Modification of CMCs 48
3.3 Preparation of Composite Gels 49
3.4 Sensitivity of Composite Gels Against Electromagnetic Wave 51
3.5 Conclusions 53
References 54
Chapter 4: Thermo-Responsive Nanofiber Mats Fabricated by Electrospinning 55
4.1 Introduction 55
4.2 Experimental 56
4.3 Results and Discussion 58
4.3.1 Synthesis and Characterization of PNIPA and PNIPA-SAX 58
4.3.2 Electrospinning and Morphology of PNIPA and PNIPA-SAX 59
4.3.3 Thermo-Response of Nanofiber Mats 61
4.4 Conclusions 65
References 65
Chapter 5: Evolution of Self-Oscillating Polymer Gels as Autonomous Soft Actuators 67
5.1 Introduction 67
5.2 Design of Self-Oscillating Polymer Gel 68
5.3 Development of Self-Oscillating Polymer Gels as Functional Soft Materials 69
5.4 Toward Artificial Cilia: Preparation of Self-Oscillating Polymer Brushes 70
5.5 Toward Autonomous Soft Machines as Polymer Solution Systems 72
5.5.1 Transmittance and Viscosity Oscillation of Polymer Solution and Microgel Dispersion 72
5.5.2 Self-Oscillating Block Copolymers 74
5.5.3 Self-Oscillating Vesicles 75
5.5.4 Cross-Linked Polymersomes Showing Self-Beating Motion 76
5.5.5 Self-Oscillating Colloidosomes 78
5.5.6 Viscosity Oscillations of Self-Oscillating Multiblock Copolymers 80
5.5.7 Amoeba-Like Self-Oscillating Polymeric Fluids with Autonomous Sol-Gel Transition 81
References 84
Chapter 6: Polyrotaxane Actuators 87
6.1 Introduction 88
6.2 Rotaxane and Polyrotaxane 89
6.2.1 Chemical and Structural Diversity of Polyrotaxanes 92
6.2.1.1 Diversity of the Cyclic Component 92
6.2.1.2 Diversity of the Polymer Backbone 93
6.2.1.3 Diversity of the Host-Guest Ratio 94
6.3 Synthesis of Polyrotaxanes 94
6.3.1 Polyrotaxane Synthesis by Template-Directed Clipping 95
6.3.2 One-Pot Multicomponent Synthesis of Polyrotaxanes 98
6.3.3 Templated Synthesis of Polyrotaxane 100
6.3.4 Synthesis of Poly[3]rotaxanes by Huisgen 1,3-Dipolarcycloaddition Reactions 101
6.3.5 Synthesis of Polyrotaxanes by [2 + 3] Nitrile N-Oxide/Acetylene Cycloaddition Reactions 102
6.3.6 Synthesis of Graft Polypseudorotaxanes and Graft Polyrotaxanes 102
6.3.7 Polypseudorotaxane and Polyrotaxane-Based Polymer Brushes 103
6.3.8 Pseudorotaxane-Assisted Formation of a Two-Dimensional (2D) Polymer 103
6.3.9 TEMPO-Mediated Oxidation: An Alternative Synthesis of Polyrotaxane 104
6.3.10 Solvent-Free Synthesis of Polyrotaxane by Grinding 104
6.3.11 Liquid Crystalline Polyrotaxane 104
6.3.12 Poly(polyrotaxane) 105
6.4 Polyrotaxanes for Molecular Machines 105
6.4.1 Types of Molecular Machines 106
6.4.2 Types of External Stimuli for Molecular Machines 107
6.4.3 Responses of Molecular Machines 109
6.4.4 Molecular Shuttle 109
6.4.4.1 Molecular Necklace 110
6.4.4.2 Light-Driven Molecular Shuttle 110
6.4.4.3 Multimode-Driven Molecular Shuttle 110
6.4.4.4 Electronically Driven Molecular Shuttle 111
6.4.5 Molecular Actuator 111
6.4.5.1 Molecular Muscles 112
6.4.5.2 Daisy Chain 113
6.4.5.3 Molecular Elevator 115
6.4.6 Molecular Switch 115
6.4.7 Piston-Cylinder 116
6.4.8 Reversible Molecular Valve 117
6.4.9 Molecular Motor 118
6.4.10 Molecular Pump 119
6.4.11 Molecular Ratchet 120
6.5 Polyrotaxanes for Soft Materials 121
6.5.1 Topological or Slide-Ring Gel 121
6.5.2 Liquid Crystalline Polyrotaxanes 123
6.5.3 Sliding Graft Copolymer 124
6.5.4 Slide-Ring Material/Natural Rubber Composites 125
6.5.5 Molecular Tubes and Insulated Molecular Wires 125
6.5.6 Photoresponsive Slide-Ring Gel 127
6.5.7 Chromic Slide-Ring 128
6.5.8 Fast Thermosensitive Hydrogels Prepared by Polyrotaxane as a Cross-Linker 128
6.5.9 Extremely Stretchable Thermosensitive Hydrogels Prepared by a Polyrotaxane Cross-Linker 130
6.5.10 Polyrotaxane-Based Resins 130
6.5.11 Polyrotaxane Fibers and Polyrotaxane/Cellulose Blend Fibers 132
6.5.12 Polyrotaxane-Based Nanocomposite Gels 133
6.5.13 Polyrotaxane-Based Materials for Biomedical Applications 133
6.6 Future Prospects of Polyrotaxanes as Actuators 139
References 141
Part III: Materials of Soft Actuators: Electro-Driven Soft Actuators 154
Chapter 7: Ionic Conductive Polymers 155
7.1 Introduction 155
7.2 Ionic Conductive Polymer Actuators 156
7.2.1 Overview 156
7.2.2 Ionic Conductive Polymers 157
7.2.3 Fabrication Methods of Electrodes for Ionic Conductive Polymer Actuators 158
7.2.4 Evaluation Methods of Driving Characteristics of Ionic Conductive Polymer Actuators 159
7.3 Recent Progress of IPMC Technologies 160
7.3.1 Multi-material IPMC with SMP and PTC Heater 160
7.3.2 Multi-material IPMC Printed by 3D Printers 161
7.3.3 Medical Welfare Applications with Ionic Conductive Polymer Actuators 163
7.4 Conclusion 168
References 169
Chapter 8: Conducting Polymers 174
8.1 Introduction 174
8.2 Mechanism of Actuation 175
8.2.1 Electrochemomechanical Actuation 175
8.2.2 Water Vapor Sorption Based Actuation 178
8.3 Measurement of Actuation 178
8.4 Characteristics and Performance 179
8.4.1 Basic Characteristics in Conducting Polymer Actuators 179
8.4.2 Polypyrrole Actuator 181
8.4.3 Polyaniline Actuator 183
8.4.4 Polyalkylthiphene and PEDOT Actuators 183
8.4.5 Ionic Liquids 183
8.5 Creep and Related Phenomena 185
8.6 Conclusion 186
References 186
Chapter 9: Humidity-Sensitive Conducting Polymer Actuators 189
9.1 Introduction 189
9.2 Experimental 190
9.3 Results and Discussion 191
9.3.1 Specific Surface Area 191
9.3.2 Water Vapor Sorption 192
9.3.3 Contraction Under Electric Field 194
9.3.4 Stress Generation and Modulus Change 197
9.3.5 Work Capacity and Energy Efficiency 199
9.3.6 Applications to Linear Actuators 199
9.4 Conclusions 202
References 202
Chapter 10: Carbon Nanotube/Ionic Liquid Composites 205
10.1 Introduction 205
10.2 Fabrication of Bucky Gel Actuator and the Actuation Mechanism 206
10.3 Measurements 207
10.4 Influence of ILs 208
10.5 Nano-Carbon Materials 211
10.6 Improving the Actuation Properties by Using Additives 212
10.7 Application 215
10.8 Conclusions 216
References 216
Chapter 11: Ion Gels for Ionic Polymer Actuators 218
11.1 Introduction 218
11.2 Materials for Ionic Polymer Actuators Using Ionic Liquids 220
11.3 Polymer Actuator Prepared by Self-Assembly of an ABA-Triblock Copolymer 221
11.4 Ionic Polymer Actuator Based on a Multi-Block Copolymer and Its Driving Mechanism 223
11.5 Sulfonated Polyimide for a High-Performance Ionic Polymer Actuator 227
References 230
Chapter 12: Ionic Liquid/Polyurethane/PEDOT:PSS Composite Actuators 234
12.1 Introduction 234
12.2 Experimental 235
12.3 Results and Discussion 236
12.3.1 Mechanical Properties of IL/PU Gels 236
12.3.2 Electrical Properties of IL/PU Gels 237
12.3.3 EAP Actuating Behavior of IL/PU/PEDOT:PSS Composites 238
12.4 Conclusions 243
References 244
Chapter 13: Dielectric Gels 245
13.1 General Background 246
13.2 Electroactive Dielectric Actuators 247
13.2.1 Gels Swollen with Dielectric Solvent 247
13.2.1.1 Behavior of Dielectric Solvent Under dc Electric Field 247
13.2.1.2 Highly Swollen Chemically Crosslinked Dielectric Gel 248
13.2.2 Possibility of Elastomers as Electroactive Dielectric Actuator 249
13.2.3 Plasticized Polymer (PVC Gel) 250
13.2.4 Solid Crystalline Polymer Film 252
13.3 Electro-Optical Functions 253
13.4 Mechano-Electric Functions 254
13.5 Concluding Remarks 255
References 256
Chapter 14: Dielectric Elastomers 259
14.1 Introduction 259
14.2 Background on DE Artificial Muscles 260
14.3 Principle of Operation of DEs 262
14.4 Materials, Fabrication, Performance, and Operating Considerations of DE Actuators 264
14.5 Unique Feature of DE Actuators 266
14.6 Principle of DE Generators 268
14.7 Innovative DE Generators 270
14.8 Toward the Future 271
14.8.1 Super Artificial Muscle 271
14.8.2 Carbon Management 272
References 272
Chapter 15: Piezoelectric Polymers 274
15.1 Introduction 274
15.2 Macroscopic Piezoelectricity of Polymers 275
15.3 Actuation of PLLA Film 277
15.3.1 PLLA Film Roll Transducer 277
15.3.2 PLLA Multilayer Film 278
15.3.2.1 Piezoelectric Performance of PDLA/PLLA Multilayer Film 282
15.3.2.2 Performance of Soft Actuator Fabricated by PDLA/PLLA Multilayer Film 283
15.4 Summary 284
References 286
Chapter 16: Thermal and Electrical Actuation of Liquid Crystal Elastomers/Gels 287
16.1 Introduction 287
16.2 Fabrication of Nematic Elastomers with Various Types of Director Configuration 289
16.3 Thermal Actuation 290
16.3.1 Thermal Elongation/Contraction of NEs with Planar or Vertical Director Configuration 290
16.3.2 Thermal Bending of NEs with Hybrid Director Configuration 292
16.3.3 Thermal Deformation of NEs with Twist Director Configuration 294
16.3.4 Thermally Induced Periodical Surface Undulation of Cholesteric Elastomers 296
16.4 Electrical Actuation 298
16.4.1 Electrical Actuation of NEs with Polydomain Director Alignment 298
16.4.2 Electrical Actuation of Cholesteric Gel Films 299
16.5 Summary 302
References 303
Part IV: Materials of Soft Actuators: Light-Driven Soft Actuators 305
Chapter 17: Spiropyran-Functionalized Hydrogels 306
17.1 Introduction 306
17.2 Past Researches on Photoresponsive Hydrogels 307
17.3 Spiropyran-Functionalized Hydrogel Actuators 307
17.3.1 Mechanism and Characteristics 307
17.3.2 Bending of Rod Actuator 310
17.3.3 Surface Profile Modulation of Sheet Actuator 311
17.3.4 On-Demand Formation of Arbitrary Microchannel 312
17.3.5 Individual Control of Microvalve Array 313
17.4 Conclusions and Future Outlook 315
References 315
Chapter 18: Photomechanical Energy Conversion with Cross-Linked Liquid-Crystalline Polymers 318
18.1 Introduction 318
18.2 Light-Driven Polymer Actuators 320
18.2.1 Photochromism 320
18.2.2 Photochemical Reaction 321
18.2.3 Photothermal Effect 322
18.3 Photomechanical Property of Cross-Linked Liquid-Crystalline Polymers 322
18.3.1 Fabrication of Cross-Linked LC Polymers 322
18.3.2 Photoinduced Deformation of LC Polymers 323
18.3.3 Light-Driven Polymer Actuators Based on Cross-Linked LC Polymers 325
18.4 Conclusion 327
References 328
Chapter 19: Photoredox Reaction 331
19.1 Introduction 331
19.2 Electrochemical Swelling and Shrinking of the Gel 332
19.3 UV-Induced Swelling of the Gel and Shrinking in the Dark 333
19.4 Partial Changes of the Gel Morphology 335
19.5 Application of the Plasmonic Photoelectrochemistry to Actuators 336
19.6 UV-Induced Swelling and Visible Light-Induced Shrinking of the Gel 337
19.7 Conclusions 338
References 339
Part V: Materials of Soft Actuators: Magneto-Driven Soft Actuators 340
Chapter 20: Magnetic Fluid Composite Gels 341
20.1 Introduction 341
20.2 Magnetic Fluid 342
20.2.1 Various Hydrodynamic Characteristics and Behavior 342
20.2.2 Deformation of Magnetic Fluid by Magnetic Field 343
20.2.2.1 Conical Meniscus 343
20.2.2.2 Swelling of the Interface by the Magnetic Field 343
20.2.2.3 Magnetic Levitation 344
20.2.2.4 Application of Magnetic Fluid 344
20.3 Magnetic Fluid Composite Gels 344
20.3.1 Magnetostriction of Magnetic Fluid Immobilized Gel 345
20.3.1.1 Immobilization Magnetic Fluid in the Gels 345
20.3.1.2 Morphology of the Magnetic Fluid Gels 345
20.3.1.3 Magneto-Striction of Magnetic Fluid Immobilized Gel 346
20.3.2 Structural Change of Magnetic Fluid Gels Induced by Magnetic Field 347
20.4 The Applications of Magnetic Fluid Composite Gels 351
20.4.1 Magnetite Immobilization in the Gel by Complexation Reaction 351
20.4.2 Release Control by Magnetic Field 352
20.4.3 Encapsulation of Magnetic Fluid for Display Device 354
20.5 Conclusion 355
References 356
Chapter 21: Magnetic Particle Composite Gels 357
21.1 Introduction 357
21.2 Magnetically Driven Actuators Made of Soft Materials 359
21.2.1 Magnetic Gel Pumps 359
21.2.2 Rotational Motion of Magnetic Gel Beads 360
21.2.3 Magnetic Gel Valves 360
21.3 Magnetic Soft Materials with Variable Viscoelasticity 361
21.4 Conclusion 368
References 369
Part VI: Modeling 371
Chapter 22: Molecular Mechanism of Electrically Induced Volume Change of Porous Electrodes 372
22.1 Introduction 372
22.2 Model 373
22.3 The Monte Carlo Simulation 374
22.4 Thermodynamic Behaviors of Ions in Porous Electrodes 375
22.4.1 Effects of Porosity 375
22.4.2 Some Simulation Results and Their Implications 376
22.4.3 Comparison with Experimentally Proposed Theories 379
22.5 Conclusions 380
References 381
Chapter 23: Computational Modeling of Mechanical Sensors Using Ionic Electroactive Polymers 382
23.1 Modeling of Ionic Electroactive Polymers 383
23.2 Black Box Model of Mechanical Sensors Using Conducting Polymers 385
23.3 Numerical Simulation of Mechanical Sensors Using Conducting Polymers 388
23.4 Numerical Simulation of Mechanical Sensors Using Hydrated IPMCs 389
23.5 Conclusions 392
References 393
Chapter 24: Distributed Parameter System Modeling 395
24.1 Introduction 396
24.2 Physics of Ionic Polymer-Metal Composite 397
24.2.1 Electrical Model 397
24.2.2 Electro-Mechanical Coupling Model: Electro-Stress Diffusion Coupling Model (Yamaue´s Model) 397
24.2.3 Mechanical Model 398
24.3 The Simplest Approximation: Linear Time Invariant State Space Equation 399
24.3.1 General Description of State Space Model and Method of Numerical Simulation 399
24.3.2 Approximation of Partial Differential Equations: Separation of Variables and Derivation of the State Space Model 399
24.3.2.1 Electrical System 399
24.3.2.2 Electro-Mechanical Coupling System 400
24.3.2.3 Mechanical System 402
24.3.2.4 Interconnection of Sub-Systems 403
24.3.3 Simulation 404
24.4 Conclusion 406
References 406
Chapter 25: Control of Electro-active Polymer Actuators with Considering Characteristics Changes 408
25.1 Introduction 408
25.2 Control of Ionic Polymer-Metal Composite Actuator 409
25.3 Self-Tuning Control 410
25.3.1 Controller Design 411
25.3.2 Parameters Updating Based on the Recursive Estimation 412
25.3.3 Results 413
25.4 Cellular Actuator Control 415
25.4.1 Control Law 416
25.4.2 Results 417
References 418
Chapter 26: Motion Design-A Gel Robot Approach 419
26.1 Gel Robot Approach 419
26.2 Agent Model of Electroactive Polymers 420
26.3 Control System Design based on the Agent Model 421
26.4 Turning Over Motion Design 421
26.4.1 Simulation of Deformation of the Electroactive Polymer Gel in Applied Electric Field 421
26.4.1.1 Migration of Surfactant Molecules Driven by the Electric Field 422
26.4.1.2 Adsorption of Surfactant Molecules to the Polymers 422
26.4.1.3 Gel Deformation Caused by Adsorption of Surfactant Molecules 423
26.4.1.4 Summary 423
26.4.2 Definition of Utility Function for Achieving Turning Over Motion 424
26.4.2.1 Abstraction of the Objective Motion 424
26.4.2.2 Spatially Varying Electric Field to Move the Center of the Gel 425
26.4.2.3 Selection of a Set of Operators 425
26.4.2.4 Phase Diagram for Switching of Operators 426
26.4.3 Application of Condition Action Rules 427
26.5 Discussion 429
References 430
Chapter 27: Motion Control 431
27.1 Introduction 431
27.2 Contraction Type PVC Gel Actuator 432
27.2.1 Configuration of a Contraction Type Actuator 432
27.2.2 Characteristics of the PVC Gel Actuator 433
27.3 Modeling and Motion Control 436
27.3.1 Modeling of the PVC Gel Actuator 436
27.3.1.1 Modeling by the Electric Impedance Measurement 436
27.3.2 Relationship Between the Current and Contraction Stress 438
27.3.3 Relationship Between the Contraction Stress and Strain 439
27.3.3.1 Modeling the Whole System of the PVC Gel Actuator 439
27.3.4 Control of the PVC Gel Actuator 440
27.3.4.1 Control Law 440
27.3.4.2 Determination of Gains 441
27.3.4.3 Feedback Control 441
27.4 Conclusions 443
References 443
Chapter 28: IPMC Actuation Mechanisms and Multi-physical Modeling 445
28.1 Introduction 446
28.2 Actuation Mechanisms 447
28.2.1 Nafion- and Flemion-IPMC 447
28.2.2 Deformation Properties 448
28.2.2.1 Nafion-IPMC 448
28.2.2.2 Flemion-IPMC 448
28.2.3 Water Phases and Relaxation Deformation 449
28.2.4 Current Response and Steady-State Deformation 452
28.2.4.1 Nafion-IPMC 452
28.2.4.2 Flemion-IPMC 453
28.2.5 Actuation Mechanisms Summary 454
28.2.5.1 Mechanism of Fast Anode Deformation 454
28.2.5.2 Mechanism of Relaxation Deformation 454
28.2.5.3 Mechanism of Slow Anode Deformation 455
28.3 Multi-physical Modeling Equations of IPMC 455
28.3.1 Electrical Field 455
28.3.2 Electrical Transport in IPMC 456
28.3.3 Chemo-mechanical Deformation in IPMC 458
28.3.3.1 Stress Field 458
Stress in Porous Composite 459
Force on the Solid/Liquid Surface 459
Pressure in the Liquid 460
Elastic Stress in the Solid 460
Stress in Sandwich Structure 461
28.3.3.2 Eigen Stresses 462
Osmotic Pressure 462
Electrostatic Stress 463
28.3.3.3 Strain Field 464
28.4 Various Effects on Electrical Transport 465
28.4.1 Inter-coupling Effect 466
28.4.2 Pressure Effect 467
28.4.3 Hydration Effect 469
28.5 Eigen Stresses and Deformation 472
28.5.1 Contribution of Each Eigen Stress to Deformation 473
28.5.2 Evolvement of Deformation with Initial Water Content 477
28.5.2.1 Osmotic Pressure 477
28.5.2.2 Electrostatic Stress 477
28.5.2.3 Relaxation Due to Eigen Stress Evolvement 478
28.5.2.4 Relaxation Due to Overcharging 479
28.5.2.5 Dielectric Constant Effect 480
28.6 Simplification of IPMC Multi-physical Model 480
28.6.1 Strict 480
28.6.2 Weak 481
28.6.3 Simplification on Transport Equations 481
28.6.4 Simplification for Eigen Stresses 482
28.6.4.1 Equivalent Eigen Stress 482
28.6.4.2 Linearization of Stresses 483
28.6.5 Experimental Verification 484
28.6.5.1 Deformation Variation with Water Content 484
Deformation Test of the First Phase 485
Deformation Test of the Second Phase 485
28.6.5.2 Deformation Fitting 485
28.7 Future Development on Physical Modeling 489
28.7.1 Electrical Double Layer and Transport Process 489
28.7.2 Chemical Reaction and Transport Process 490
28.7.3 Chemical Eigen Stresses 490
28.7.4 Method of Numerical Analysis 490
References 491
Chapter 29: Sensing Properties and Physical Model of Ionic Polymer 493
29.1 Introduction 493
29.2 IPMC Sensing Properties with Ambient Humidity 495
29.2.1 Material and Measurement Preparation 496
29.2.2 Voltage Response When Varying Water Content 497
29.3 Voltage Response of IPMC Sensor with Various Cations 501
29.3.1 Static Voltage Response 502
29.3.1.1 Voltage Rising Process 502
29.3.1.2 Negative Steady-State Voltage 502
29.3.1.3 Disappearance of Voltage Decay 504
Initial Fast Voltage Increase 504
Slow Voltage Decay 507
29.3.2 Dynamic Voltage Response 509
29.3.2.1 High Ambient Humidity 509
29.3.2.2 Moderate Ambient Humidity 510
29.3.2.3 Low Ambient Humidity 511
29.4 Current Response of IPMC Sensor with Various Cations 512
29.4.1 Static Current Response 512
29.4.1.1 Current Peak 512
29.4.1.2 Current Decay 512
29.4.1.3 Free Oscillation Decay 514
29.4.2 Dynamic Current Response 516
29.5 IPMC Sensing Physical Model 517
29.5.1 Multi-physical Model Equations 518
29.5.1.1 Mechanical Field 518
Stress Field in Polymer 518
Pressure in Ion Cluster 519
29.5.1.2 Transport Process in Chemical Field 519
Convection Under Pressure 519
Electrical Migration of Built-In Field 520
Inter-coupling Effect Between Water and Cation 520
29.5.1.3 Electrical Field 521
29.5.2 Numerical Analysis on Transport Process 521
29.5.2.1 Water Transport Under Pressure 522
29.5.2.2 Electrical Migration by Built-In Field 523
29.5.2.3 Inter-coupling Effect 525
29.5.3 Electrical Response of IPMC Sensor 528
29.6 Future Development on Extended Ionic Polymer Sensor 530
References 532
Chapter 30: Modeling of Dielectric Elastomer Actuator 536
30.1 Introduction 536
30.2 DEA Free Energy Model 538
30.2.1 The Thermodynamic System 538
30.2.2 Nonlinear Mechanics 541
30.3 Electromechanical Instability in DEA 543
30.3.1 Mechanism of Instability 543
30.3.2 Suppressing the Snap-Through Instability 544
30.4 Harnessing the Instability for New DEA Performance 546
30.4.1 Harnessing the Snap-Through 546
30.4.2 Harnessing the Crater Instability 546
30.5 Conclusion 547
References 548
Chapter 31: Modeling of Dielectric Gel Using Multi-physics Coupling Theory 550
31.1 Introduction 550
31.2 Dielectric Gel: Actuation Mechanism and Characteristics 551
31.2.1 Actuation of Dielectric Gel 551
31.2.2 Deformation Character of Dielectric Gel 553
31.3 A Free Energy Model for the Dielectric Gel 554
31.4 Cases of Dielectric Gel Actuation 557
31.4.1 Phase Transition 557
31.4.2 Constrained Expansion 559
31.4.3 Gel Piston 560
31.4.4 Contractile Actuation 564
31.5 Applications of Dielectric Gel 566
31.5.1 An Amoeba Robot 566
31.5.2 An Artificial Lens 566
31.5.3 Soft Exoskeleton 566
31.6 Conclusion 567
References 568
Chapter 32: Modeling and Control of Fishing-Line/Sewing-Thread Artificial Muscles (Twisted and Coiled Polymer Fibers, TCPFs) 570
32.1 Introduction 571
32.2 Physics, Material, and Types of Fishing-Line/Sewing-Thread Artificial Muscle Actuators 571
32.2.1 Physics and Material of Fishing-Line Artificial Muscles 571
32.2.2 Types of Fishing-Line/Sewing-Thread Artificial Muscle Actuators 572
32.3 Fabrication of Coiled Type Actuators and Electrothermal Actuation by Joule Heating 573
32.3.1 Fabrication of Twisted and Coiled Polymer Fiber (TCPF) Actuators 573
32.3.2 Joule Heating by Nichrome Wire 574
32.4 Modeling 575
32.4.1 Linear Dynamical Model for TCPFs 575
32.4.2 System Identification 576
32.5 Position Control Based on Model-Based Design 578
32.5.1 PID Feedback and Input Linearization 578
32.5.2 Performance Improvement by Feedforward Controller 579
32.5.3 Experiment of Position Control 579
32.5.4 Cooling Control Using a Controllable Fan 580
32.5.5 Experiment of Cooling Control 582
32.6 Conclusions 583
References 584
Part VII: Applications 586
Chapter 33: Underwater Soft Robots 587
33.1 Introduction 588
33.2 Autonomous Ray-Like Robot 589
33.2.1 Development of the Ray-Like Robot 589
33.2.1.1 Design of the Fin Using IPMC 589
33.2.1.2 Electrical Devices for Autonomous Operation 590
33.2.2 Design of the Control Input 590
33.2.2.1 Traveling Wave of the Fin 590
33.2.2.2 Design of the Voltage Input to the Actuators 591
33.2.3 Experiments 591
33.2.3.1 Measurement of the Propulsion Speed 592
33.2.3.2 Measurement of the Amplitude of the Traveling Wave 592
33.2.3.3 Discussions 593
33.3 Quadruped Robot with Fully Polymer Body 594
33.3.1 Development of the Quadruped Robot 594
33.3.2 Design of the Control Input 596
33.3.2.1 Design of the Walking Pattern, Gait 596
33.3.2.2 Feedforward Controller for Smoothing the Voltage Input 597
33.3.3 Experiment 597
33.3.3.1 Method 597
33.3.3.2 Results and Discussions 598
33.4 Conclusion 599
References 600
Chapter 34: IPMC Actuator-Based Multifunctional Underwater Microrobots 602
34.1 Introduction 603
34.2 Biomimetic Locomotion 605
34.2.1 IPMC Actuators 605
34.2.2 Bio-Inspired Locomotion 606
34.2.2.1 Stick Insect-Inspired Walking Locomotion 606
34.2.2.2 Jellyfish-Like Floating Locomotion 607
34.2.2.3 Butterfly-Inspired Swimming Locomotion 607
34.2.2.4 Inchworm-Inspired Crawling Locomotion 608
34.3 Developed Microrobots 608
34.4 Proposed Multifunctional Lobster-Like Microrobot 611
34.4.1 Actual Lobsters 611
34.4.2 Proposed Lobster-Like Microrobot 611
34.4.3 Crawling and Rotating Mechanism 612
34.4.4 Floating Mechanism 613
34.4.5 Grasping Mechanism 613
34.4.6 Control System 613
34.5 Prototype Microrobot and Experiments 613
34.5.1 Prototype of the Lobster-Like Microrobot 613
34.5.2 Walking Experiments 614
34.5.3 Rotating Experiments 615
34.5.4 Floating Experiments 615
34.5.5 Walking, Rotating and Hand Manipulation Experiments 616
34.5.6 Obstacle-Avoidance Experiments 616
34.6 Discussion 618
34.7 Conclusion 619
References 620
Chapter 35: Medical Applications 623
35.1 Surgical Applications 623
35.2 Catheter Applications 624
35.3 Transport Systems 624
35.4 Active Scaffolds for Regenerative Medicine 625
35.5 Artificial Voice Synthesis 626
35.6 Drug Delivery System 628
References 628
Chapter 36: Elastomer Transducers 630
36.1 Introduction 630
36.2 Background on DE Transducers 631
36.3 DE Actuators and DE Sensors 632
36.3.1 Application of Robots (Includes Care and Rehabilitation Purposes) and Sensors 632
36.3.2 Application to Audio Equipment 633
36.3.3 Other Applications 635
36.4 Application of DE Generation Devices 636
36.4.1 DE Wave Generation 637
36.4.2 Solar Heat Generator Using DE 639
36.4.3 DE Water Mill Generators 640
36.4.4 Portable DE Generators 641
36.4.5 Wearable Generators 641
36.4.6 Production of Hydrogen 642
36.4.7 Sites Where Power Generation Using DEs Is Possible 643
36.5 Future of DE 643
References 644
Chapter 37: Dielectric Elastomer Sensors: Development of a Stretchable Strain Sensor System 646
37.1 Introduction 646
37.2 Features of the Stretch Sensor 647
37.2.1 Measurement Principle and Basic Characteristics 647
37.2.2 Features of the Stretch Sensor 649
37.3 Application Example of a Stretch Sensor 651
37.3.1 Measurement of Articulation Motion (Motion Sensing) 651
37.3.2 Interface 653
37.3.3 Wearable Switch 654
37.3.4 Respiratory Rate Assessment Tool 655
37.3.5 Swallowing Function Evaluation Tool 658
37.4 Conclusion 659
References 660
Part VIII: Next-Generation Bio-actuators 661
Chapter 38: Tissue-Engineering Approach to Making Soft Actuators 662
38.1 Introduction 662
38.2 Tissue Engineering and Regenerative Medicine 663
38.3 Muscle Tissue as an Actuator 664
38.4 Tissue-Engineered Skeletal Muscle 666
38.5 Our Tissue-Engineered Skeletal Muscle 666
38.6 Contractile Property and Gene Expression of Tissue-Engineered Muscle 668
38.7 Tissue-Engineered Muscle for Bioactuators 669
38.8 Further Study and Conclusion 671
References 672
Chapter 39: Integration of Soft Actuators Based on a Biomolecular Motor System to Develop Artificial Machines 674
39.1 Introduction 675
39.2 Microtubule-Kinesin, an ATP-Driven Biomolecular Actuator 675
39.3 Active Self-Organization of a Biomolecular Motor System with Controlled Morphologies and Motions 676
39.4 Control of Self-Organization of Biomolecular Motors Exhibiting Collective Motion 679
39.5 Mechanical Oscillation Emerging from Self-Organization of Biomolecular Motors 680
39.6 Biomimetic Devices Based on a Self-Organized Biomolecular Motor System 681
39.6.1 Construction of Artificial Cilia by Integration of Biomolecular Motors 681
39.6.2 Controlling Spatial Organization of Biomolecular Motors in Cell-Like Biomimetic Constraints 682
39.7 Biomolecular Motor System as a Sensor of Surface Mechanical Deformation 685
39.8 Molecular Swarm Robots Based on the Biomolecular Actuators 687
39.9 Future Outlook 688
References 689
Chapter 40: Employing Cytoskeletal Treadmilling in Bio-actuators 693
40.1 Introduction 693
40.2 What Is Treadmilling? 695
40.3 Studies of Treadmilling Systems 697
40.4 Supra-Macromolecular Hierarchical Cytoskeletal Protein Hydrogels 698
40.5 Further Attractive Aspects and Remaining Tasks of Treadmilling Proteins 701
40.6 Conclusions 702
References 702
Chapter 41: Construction and Functional Emergence of Bioactuated Micronanosystem and Living Machined Wet Robotics 705
41.1 Introduction 705
41.2 Bioactuator Using Muscle Cells 707
41.3 Bioactuator with Superior Environmental Resistance 708
41.4 Bioactuator Created by the Three-Dimensional Tissue Architecture of Muscle Cells and Its Application 709
41.4.1 Myocardial Gel Actuator 710
41.4.2 Motion Control of Muscle Tissue by Cultured Neural Network 711
41.5 Light Control of Muscle Cell Bioactuator 713
41.6 Study of the High Performance of the Bioactuator and Evaluation Methods 715
41.6.1 Mechanical Stimulation of Bioactuators 715
41.6.2 Evaluation of Mechanical Properties of Bioactuators 716
41.6.3 Evaluation of Thermal Properties of Cells 718
41.7 Conclusion and Future Prospects 719
References 720