Photomechanical Materials, Composites, and Systems: Wireless Transduction of Light into Work

An exhaustive review of the history, current state, and future opportunities for harnessing light to accomplish useful work in materials, this book describes the chemistry, physics, and mechanics of light-controlled systems. •    Describes photomechanical materials and mechanisms, along with key applications •    Exceptional collection of leading authors, internationally recognized for their work in this growing area •    Covers the full scope of photomechanical materials: polymers, crystals, ceramics, and nanocomposites •    Deals with an interdisciplinary coupling of mechanics, materials, chemistry, and physics •    Emphasizes application opportunities in creating adaptive surface features, shape memory devices, and actuators; while assessing future prospects for utility in optics and photonics and soft robotics

Table of Contents:
List of Contributors xi Preface xv 1 A Historical Overview of Photomechanical Effects in Materials, Composites, and Systems 1 Toru Ube and Tomiki Ikeda 1.1 Introduction 1 References 25 2 Photochromism in the Solid State 37 Oleksandr S. Bushuyev and Christopher J. Barrett 2.1 Molecular Photoswitches in the Solid State 37 2.2 Molecular and Macroscopic Motion of Azobenzene Chromophores 39 2.3 Photomechanical Effects 41 2.4 Solid-State Photochromic Molecular Machines 54 2.5 Surface Mass Transport and Phase Change Effects 62 2.6 Photochromic Reactions in Framework Architectures 65 2.7 Summary and Outlook 68 References 69 3 Photomechanics: Bend, Curl, Topography, and Topology 79 Daniel Corbett, Carl D. Modes, and Mark Warner 3.1 The Photomechanics of Liquid-Crystalline Solids 81 3.2 Photomechanics and Its Mechanisms 82 3.3 A Sketch of Macroscopic Mechanical Response in LC Rubbers and Glasses 92 3.4 Photo- and Heat-Induced Topographical and Topological Changes 97 3.5 Continuous Director Variation, Part 1 97 3.6 Mechanico-Geometric Effects, Part 1 100 3.7 Continuous Director Variation, Part 2 100 3.8 Continuous Director Variation, Part 3 103 3.9 Mechanico-Geometric Effects, Part 2 106 3.10 Director Fields with Discontinuities–Advanced Origami! 107 3.11 Mechanico-Geometric Consequences of Nonisometric Origami 110 3.12 Conclusions 110 References 112 4 Photomechanical Effects in Amorphous and Semicrystalline Polymers 117 Jeong JaeWie 4.1 Introduction 117 4.2 Polymeric Materials 119 4.3 The Amorphous Polymer State 119 4.4 The Semicrystalline Polymer State 121 4.5 Absorption Processes 124 4.6 Photomechanical Effects in Amorphous and Semicrystalline Azobenzene-Functionalized Polymers 126 4.7 Molecular Alignment 132 4.8 Annealing and Aging 138 4.9 Sub-Tg SegmentalMobility 142 4.10 Cross-Link Density 145 4.11 Concluding Remarks 146 References 148 5 Photomechanical Effects in Liquid-Crystalline Polymer Networks and Elastomers 153 Timothy J. White 5.1 Introduction 153 5.2 Optically Responsive Liquid Crystal Polymer Networks 159 5.3 Literature Survey 165 5.4 Outlook and Conclusion 169 References 171 6 Photomechanical Effects in Polymer Nanocomposites 179 Balaji Panchapakesan, Farhad Khosravi, James Loomis, and Eugene M. Terentjev 6.1 Introduction 179 6.2 Photomechanical Actuation in Polymer–Nanotube Composites 180 6.3 Fast Relaxation of Carbon Nanotubes in Polymer Composite Actuators 186 6.4 Highly Oriented Nanotubes for Photomechanical Response and Flexible Energy Conversion 191 6.5 Photomechanical Actuation Based on 2-D Nanomaterial (Graphene)–Polymer Composites 205 6.6 Applications of Photomechanical Actuation in Nanopositioning 213 6.7 Future Outlook 224 Acknowledgments 225 References 225 7 Photomechanical Effects in Photochromic Crystals 233 Lingyan Zhu, Fei Tong, Rabih O. Al-Kaysi, and Christopher J. Bardeen 7.1 Introduction 233 7.2 General Principles for Organic Photomechanical Materials 234 7.3 History and Background 234 7.4 Modes of Mechanical Action 240 7.5 Photomechanical Molecular Crystal Systems 242 7.6 Future Directions 260 7.7 Conclusion 264 Acknowledgments 264 References 264 8 Photomechanical Effects in Piezoelectric Ceramics 275 Kenji Uchino 8.1 Introduction 275 8.2 Photovoltaic Effect 276 8.3 Photostrictive Effect 288 8.4 Photostrictive Device Applications 294 8.5 Concluding Remarks 299 References 300 9 Switching Surface Topographies Based on Liquid Crystal Network Coatings 303 Danqing Liu and Dirk J. Broer 9.1 Introduction 303 9.2 Liquid Crystal Networks 304 9.3 Conclusions 322 References 322 10 Photoinduced Shape Programming 327 Taylor H.Ware 10.1 One-Way Shape Memory 329 10.2 Two-Way Shape Memory 343 10.3 Summary and Outlook 358 References 358 11 Photomechanical Effects to Enable Devices 369 M. Ravi Shankar 11.1 Introduction 369 11.2 Analog Photomechanical Actuators 371 11.3 Discrete-State (Digital) Photomechanical Actuators 373 11.4 Photomechanical Mechanisms and Machines 387 References 388 12 Photomechanical Effects in Materials, Composites, and Systems: Outlook and Future Challenges 393 Timothy J.White 12.1 Introduction 393 12.2 Outlook and Challenges 393 12.3 Conclusion 401 References 401 Index 405

About the Author :
Timothy J. White, PhD, lives and works in Dayton, OH. Dr. White is a leading researcher in the soft materials community, recently recognized by awards from the MRS, ACS, and SPIE. His research has generally focused on photoinduced effects in materials. Dr. White has published more than 100 peer-reviewed papers.