Thin Film Shape Memory Alloys: Fundamentals and Device Applications

Half-title......Page 3
Title......Page 5
Copyright......Page 6
Contents......Page 7
Contributors......Page 15
Preface......Page 17
2 Martensitic transformation in Ti-Ni alloys......Page 20
5 Crystallization and microstructural development......Page 21
8 Ion implantation processing and associated irradiation effects......Page 22
10 Overview of thin film shape memory alloy applications......Page 23
13 TiNi thin film devices......Page 24
15 Superelastic thin films and applications for medical devices......Page 25
18 Shape memory thin film composite microactuators......Page 26
19 TiNi thin film shape memory alloys for optical sensing applications......Page 27
1.1 Introduction......Page 29
1.2.1 Film deposition......Page 33
1.2.2 TiNi film characterization......Page 37
Basic characteristics......Page 39
Strain associated transformations......Page 40
Superelastic behavior......Page 42
Texture and transformation strain anisotropy......Page 43
Strength and ductility......Page 45
Microstructure of age-treated thin films......Page 47
Aging effect......Page 49
Non-equilibrium phase and composition......Page 54
Strengthening mechanism......Page 57
1.2.3.1 TiNiCu films......Page 58
1.2.3.2 TiNiPd films......Page 64
1.2.4 Residual stress and stress evolution......Page 67
1.2.5 Frequency response......Page 68
1.2.7 Stability, degradation and fatigue......Page 69
1.2.8 Film thickness effect......Page 73
1.2.9 Temperature memory effect......Page 74
1.2.10 Nanoscale mechanical evaluation......Page 75
1.2.11 Functionally graded and composite TiNi based films......Page 76
1.3.1 Comparison of various microactuation mechanisms......Page 77
1.3.2 Modeling and optimal design of TiNi thin film microactuators......Page 79
1.3.3 Freestanding microactuators based on a two-way shape memory effect......Page 80
1.3.4 TiNi diaphragms, micropump and microvalves......Page 84
1.3.5 Microgrippers......Page 88
1.3.6 Microsensors, microswitches and microrelays......Page 90
1.3.7 Other applications......Page 91
1.4 Summary......Page 92
References......Page 93
2.1 Introduction......Page 101
2.3 Crystallography of martensitic transformation......Page 102
2.4 Transformation strain......Page 105
2.5 Transformation temperatures......Page 107
2.6 Shape memory and superelasticity based on martensitic transformation......Page 109
2.7 Deformation behavior......Page 110
References......Page 114
3.1 Introduction to methods of making TiNi thin film......Page 116
3.2 Sputter deposition......Page 117
3.3 Description of the sputtering process......Page 118
3.5 Methods of joining thin film......Page 124
3.5.1 Resistance welding......Page 126
3.6.1 Heat treatment......Page 127
3.6.3 Sacrificial layer......Page 128
3.8 Fabrication of intravascular medical devices......Page 129
3.8.1 Planar sputtering on a three-dimensional substrate......Page 131
3.8.2 Sputtering using the multiple-layering method......Page 132
3.9 Literature of TiNi thin film......Page 134
Acknowledgements......Page 135
References......Page 136
4.1 Introduction......Page 138
4.2 Fabrication of multi-layer TiNi thin films......Page 139
4.3.1 DSC measurements......Page 140
4.3.2 XRD measurements......Page 141
4.3.3 TEM observation......Page 142
4.4 Shape memory properties and mechanical properties......Page 146
References......Page 149
5.1 Introduction......Page 152
5.2.1 Crystallization principles......Page 153
5.2.2 Crystallization theory (Johnson–Mehl–Avrami–Kolmogorov theory)......Page 154
5.2.2.1 The Avrami exponent, n......Page 155
5.3 Crystallization kinetics of TiNi thin films......Page 156
Differential scanning calorimetry......Page 157
X-ray diffraction......Page 158
5.3.1.2 Quantitative direct methods......Page 159
5.3.2 A background of TiNi crystallization studies......Page 160
Compositional effects......Page 162
Substrate effects......Page 164
Ni-rich films......Page 165
Ti-rich films......Page 166
References......Page 168
6.1 Shape memory behavior of TiNi thin films......Page 173
6.2 Shape memory behavior of Ni-rich Ti-Ni thin films......Page 174
6.3 Shape memory behavior of Ti-rich TiNi thin films......Page 180
6.5 Two-way shape memory effect......Page 186
6.6 Superelasticity......Page 187
6.7 Stress–strain curves of TiNi thin films......Page 188
6.8 Thickness effect of shape memory behavior......Page 189
6.9 Summary......Page 190
References......Page 191
7.1 Introduction......Page 194
7.2.1 Curvature method......Page 196
7.2.2 X-ray diffraction......Page 197
7.3.1 Stress evolution in shape memory events......Page 198
7.3.2 Factors affecting stress evolution......Page 200
7.3.2.1 Ti/Ni ratio......Page 201
7.3.2.2 Post annealing......Page 202
7.3.2.3 Thermal cycling......Page 203
7.3.2.4 Film thickness......Page 204
7.4.1 Transition between surface relief and wrinkling......Page 205
7.4.2 Reversible trenches......Page 208
7.4.3 Theoretical analysis of stress-induced wrinkling and trenches......Page 209
7.5 Novel methods in surface morphology characterization......Page 211
7.5.1 Atomic force microscopy......Page 212
7.5.2 Photoemission electron microscopy......Page 213
7.6 Summary......Page 217
References......Page 218
8.1 Introduction......Page 221
8.2.1.1 Nuclear stopping and cascade formation......Page 222
8.2.1.3 Calculation of the stopping powers and radiation dose......Page 223
8.2.2.1 Implantation dose and temperature effects on the irradiated microstructure......Page 224
8.2.2.2 X-ray studies......Page 225
8.2.2.3 TEM observations of as-irradiated microstructure......Page 227
8.2.2.5 Effect of pre-straining the martensite on amorphization processes......Page 232
Results from the X-ray diffraction......Page 233
TEM observations......Page 234
8.2.3 High energy ion irradiation – electronic stopping effects......Page 236
8.2.4 Linking the high energy ion experiments to the electronic stopping effects in 5 MeV Ni ions......Page 239
8.3 Using ion beam modification to make novel actuator materials......Page 240
8.3.1 Actuator design concept......Page 241
8.3.2.1 Bending of films irradiated at 25 C......Page 244
8.3.2.3 Comparing film curling of specimens irradiated at the two different temperatures......Page 246
8.3.3 Cyclic fatigue, decay of two-way shape strains......Page 249
8.4 Summary......Page 251
References......Page 252
9.1 Introduction......Page 254
9.2 Experimental demonstration......Page 256
9.3.1.1 Fresnel equations......Page 259
9.3.1.2 Absorption of laser radiation by metals......Page 261
9.3.1.4 Absorption of laser energy in multilayer structures......Page 262
9.3.2 Backside CO2 laser annealing......Page 264
9.3.2.2 Temperature distribution......Page 265
9.3.2.3 Effects of oxidation and interfacial layers......Page 270
Effect of surface roughness......Page 273
Effect of an oxide layer......Page 274
9.3.3 Direct laser annealing......Page 275
9.3.3.1 Absorption of a Si/TiNi/Si multilayer......Page 276
9.3.3.2 Effects of oxidation and interfacial layer......Page 278
9.3.3.3 Remarks......Page 282
9.3.4 Annealing of Ni/Ti multilayer thin films......Page 283
9.4 Summary......Page 285
References......Page 286
10.1 Introduction to TiNi thin film applications......Page 289
10.2 Properties suitable for applications......Page 290
10.2.1 Mechanical properties......Page 291
10.2.3 Corrosion behavior of thin films......Page 293
10.2.4 Biocompatibility of thin films......Page 294
10.3.1 Microactuators......Page 295
10.3.2 Fluid control......Page 296
10.3.3 Microswitches......Page 297
10.4 Superelastic applications and medical devices......Page 299
10.5 Summary......Page 300
References......Page 301
11.1 Introduction......Page 303
11.2 A theory of pressurized thin film......Page 306
11.3.1 Single crystal film......Page 308
11.3.2 Polycrystalline film......Page 312
11.3.2.2 Long columnar grains......Page 313
11.4.1 Free energy......Page 314
11.4.2 Evolution of microstructure under driving forces......Page 316
11.4.3 Self-accommodation patterns......Page 317
11.4.3.1 (001) film......Page 318
11.4.3.3 111) film......Page 319
11.5.1 Single crystal micropumps......Page 320
11.5.2 Polycrystalline micropumps......Page 321
11.6 Summary......Page 323
References......Page 324
12.1 Introduction......Page 328
12.2 Shape memory behaviour of TiNi thin films......Page 329
12.3 Fabrication and characterization methods......Page 333
12.4.1 Microactuators using the R-phase of TiNi......Page 337
12.4.2 Microactuators using the M phase of TiNiPd......Page 338
12.4.3 Dynamic actuation of microactuators......Page 339
12.5 Microactuators using the M phase of TiNiCu......Page 342
References......Page 346
13.1 Introduction......Page 349
13.3 Thin film properties......Page 351
13.4 TiNi thin film devices......Page 352
13.4.1 Mechanical devices......Page 353
13.4.1.1 Bubble actuator......Page 354
13.4.1.2 Micropump......Page 357
13.4.1.3 Microwrapper......Page 358
13.4.1.4 Microvalves......Page 361
13.4.2 Biomedical devices......Page 364
13.4.2.1 Heart valve......Page 365
13.4.2.2 Covered stent......Page 366
References......Page 369
14.1 Introduction......Page 374
14.2 Overview......Page 375
14.3 Valve layout......Page 378
14.4 SMA materials......Page 382
14.5 Modeling and simulation aspects......Page 383
14.6 Fabrication......Page 388
14.7.1 Polymer seat microvalves......Page 390
14.7.2 Microfluidic controller......Page 394
14.8 Summary......Page 395
References......Page 396
15.1 Introduction......Page 398
15.2 Superelasticity in thin films......Page 400
15.3 Fabrication of planar superelastic thin films......Page 403
15.4 Patterning of planar films using lithography and etching......Page 405
15.5 Fabrication of superelastic thin film tubes......Page 406
15.6 Patterning of non-planar films using lithography and etching......Page 409
15.7 Summary......Page 410
References......Page 411
16.1 Introduction......Page 413
16.2.1 Sputter deposition system......Page 414
16.2.2 Characterization of shape memory behaviour......Page 415
16.3.1 Cross-sectional microstructure......Page 416
16.3.2 Shape memory behavior and fracture strength......Page 418
16.4.1 Film thickness......Page 419
16.4.2 Surface roughness......Page 421
16.4.3 Columnar grain formation......Page 424
16.5.2 Effect of rotation speed on shape memory behavior and fracture strength......Page 425
16.5.3 Superelasticity......Page 428
Acknowledgement......Page 429
References......Page 430
17.1 Introduction......Page 431
17.2 Freestanding TiNiCu microcage......Page 434
17.3.1 Design considerations......Page 439
17.3.2 Fabrication and characterization......Page 443
17.4 Biological study of the TiNi film......Page 447
17.5 Summary......Page 450
References......Page 451
18.1 Introduction......Page 454
18.3 Fabrication of shape memory composites......Page 455
18.4 Bistable SMA composites......Page 456
18.5 Phase-coupled SMA composites......Page 459
18.6 Applications of shape memory thin film composites......Page 461
References......Page 463
19.1 Introduction......Page 465
19.2 Optical application based on the surface morphology change......Page 468
19.3 Optical application based on free standing TiNi film......Page 472
19.4.1 TiNi/Si bimorph structure......Page 474
19.4.2 TiNi/Si3N4 microcantilever......Page 478
19.5 TiNi film for infrared image application......Page 479
References......Page 483
 Index......Page 485