Patterning or lithography is at the core of modern science and technology and cuts across all disciplines. With the emergence of nanotechnology, conventional methods based on electron beam lithography and extreme ultraviolet photolithography have become prohibitively expensive. As a result, a number of simple and unconventional methods have been introduced, beginning first with research demonstrations in the mid 1990s. This book focuses on these unconventional patterning techniques and their applications to optics, organic devices, electronic devices, biological devices, and fluidics.

Table of Contents:
PREFACE xv I NANOPATTERNING TECHNIQUES 1 1 INTRODUCTION 3 2 MATERIALS 7 2.1 Introduction 7 2.2 Mold Materials and Mold Preparation 8 2.2.1 Soft Molds 8 2.2.2 Hard Molds 19 2.2.3 Rigiflex Molds 19 2.3 Surface Treatment and Modification 21 References 23 3 PATTERNING BASED ON NATURAL FORCE 27 3.1 Introduction 27 3.2 Capillary Force 28 3.2.1 Open-Ended Capillary 29 3.2.2 Closed Permeable Capillary 31 3.2.3 Completely Closed Capillary 40 3.2.4 Fast Patterning 43 3.2.5 Capillary Kinetics 45 3.3 London Force and Liquid Filament Stability 48 3.3.1 Patterning by Selective Dewetting 49 3.3.2 Liquid Filament Stability: Filling and Patterning 51 3.4 Mechanical Stress: Patterning of A Metal Surface 56 References 63 4 PATTERNING BASED ON WORK OF ADHESION 67 4.1 Introduction 67 4.2 Work of Adhesion 68 4.3 Kinetic Effects 71 4.4 Transfer Patterning 74 4.5 Subtractive Transfer Patterning 79 4.6 Transfer Printing 82 References 91 5 PATTERNING BASED ON LIGHT: OPTICAL SOFT LITHOGRAPHY 95 5.1 Introduction 95 5.2 System Elements 96 5.2.1 Overview 96 5.2.2 Elastomeric Photomasks 96 5.2.3 Photosensitive Materials 99 5.3 Two-Dimensional Optical Soft Lithography (OSL) 100 5.3.1 Two-Dimensional OSL with Phase Masks 100 5.3.2 Two-Dimensional OSL with Embossed Masks 104 5.3.3 Two-Dimensional OSL with Amplitude Masks 105 5.3.4 Two-Dimensional OSL with AmplitudePhase Masks 109 5.4 Three-Dimensional Optical Soft Lithography 110 5.4.1 Optics 111 5.4.2 Patterning Results 112 5.5 Applications 117 5.5.1 Low-Voltage Organic Electronics 117 5.5.2 Filters and Mixers for Microfluidics 118 5.5.3 High Energy Fusion Targets and Media for Chemical Release 118 5.5.4 Photonic Bandgap Materials 120 References 122 6 PATTERNING BASED ON EXTERNAL FORCE: NANOIMPRINT LITHOGRAPHY 129 L. Jay Guo 6.1 Introduction 129 6.2 NIL MOLD 133 6.2.1 Mold Fabrication 133 6.2.2 Mold Surface Preparation 137 6.2.3 Flexible Fluoropolymer Mold 137 6.3 NIL Resist 138 6.3.1 Thermoplastic Resist 139 6.3.2 Copolymer Thermoplastic Resists 141 6.3.3 Thermal-Curable Resists 142 6.3.4 UV-Curable Resist 146 6.3.5 Other Imprintable Materials 148 6.4 The Nanoimprint Process 149 6.4.1 Cavity Fill Process 149 6.5 Variations of NIL Processes 152 6.5.1 Reverse Nanoimprint 152 6.5.2 Combined Nanoimprint and Photolithography 155 6.5.3 Roll-to-Roll Nanoimprint Lithography (R2RNIL) 156 6.6 Conclusion 159 References 160 7 PATTERNING BASED ON EDGE EFFECTS: EDGE LITHOGRAPHY 167 Matthias Geissler, Joseph M. McLellan, Eric P. Lee and Younan Xia 7.1 Introduction 167 7.2 Topography-Directed Pattern Transfer 169 7.2.1 Photolithography with Phase-Shifting Masks 170 7.2.2 Use of Edge-Defined Defects in SAMs 172 7.2.3 Controlled Undercutting 175 7.2.4 Edge-Spreading Lithography 176 7.2.5 Edge Transfer Lithography 178 7.2.6 Step-Edge Decoration 180 7.3 Exposure of Nanoscale Edges 181 7.3.1 Fracturing of Thin Films 182 7.3.2 Sectioning of Encapsulated Thin Films 182 7.3.3 Thin Metallic Films along Sidewalls of Patterned Stamps 184 7.3.4 Topographic Reorientation 186 7.4 Conclusion and Outlook 187 References 188 8 PATTERNING WITH ELECTROLYTE: SOLID-STATE SUPERIONIC STAMPING 195 Keng H. Hsu, Peter L. Schultz, Nicholas X. Fang, and Placid M. Ferreira 8.1 Introduction 195 8.2 Solid-State Superionic Stamping 197 8.3 Process Technology 199 8.4 Process Capabilities 203 8.5 Examples of Electrochemically Imprinted Nanostructures Using the S4 Process 208 Acknowledgments 211 References 211 9 PATTERNING WITH GELS: LATTICE-GAS MODELS 215 Paul J. Wesson and Bartosz A. Grzybowski 9.1 Introduction 215 9.2 The RDF Method 218 9.3 Microlenses: Fabrication 218 9.4 Microlenses: Modeling Aspects 220 9.4.1 Modeling Using PDEs 220 9.4.2 Modeling Using Lattice-Gas Method 221 9.5 RDF at the Nanoscale 222 9.5.1 Nanoscopic Features from Counter-Propagating RD Fronts 222 9.5.2 Failure of Continuum Description 225 9.5.3 Lattice-Gas Models at the Nanoscale 227 9.6 Summary and Outlook 229 References 230 10 PATTERNING WITH BLOCK COPOLYMERS 233 Jia-Yu Wang, Wei Chen, and Thomas P. Russell 10.1 Introduction 233 10.2 Orientation 235 10.2.1 Self-Assembling 235 10.2.2 Self-Directing 247 10.3 Long-Range 254 10.3.1 Solvent Annealing 254 10.3.2 Graphoepitaxy 256 10.3.3 Sequential, Orthogonal Fields 260 10.4 Nanoporous BCP Films 262 10.4.1 Ozonolysis 264 10.4.2 Thermal Degradation 264 10.4.3 UV Degradation 267 10.4.4 Selective Extraction 271 10.4.5 “Soft” Chemical Etch 272 10.4.6 Cleavable Junction 272 10.4.7 Solvent-Induced Film Reconstruction 274 References 276 11 PERSPECTIVE ON APPLICATIONS 291 II APPLICATIONS 293 12 SOFT LITHOGRAPHY FOR MICROFLUIDIC MICROELECTROMECHANICAL SYSTEMS (MEMS) AND OPTICAL DEVICES 295 Svetlana M. Mitrovski, Shraddha Avasthy, Evan M. Erickson, Matthew E. Stewart, John A. Rogers, and Ralph G. Nuzzo 12.1 Introduction 295 12.2 Microfluidic Devices for Concentration Gradients 297 12.3 Electrochemistry and Microfluidics 300 12.4 PDMS and Electrochemistry 302 12.5 Optics and Microfluidics 306 12.6 Unconventional Soft Lithographic Fabrication of Optical Sensors 314 Acknowledgments 317 References 318 13 UNCONVENTIONAL PATTERNING METHODS FOR BIONEMS 325 Pilnam Kim, Yanan Du, Ali Khademhosseini, Robert Langer, and Kahp Y. Suh 13.1 Introduction 325 13.2 Fabrication of Nanofluidic System for Biological Applications 326 13.2.1 Unconventional Methods for Fabrication of Nanochannel 326 13.2.2 Application of Nanofluidic System 332 13.3 Fabrication of Biomolecular Nanoarrays for Biological Applications 338 13.3.1 DNA Nanoarray 338 13.3.2 Protein Arrays 340 13.3.3 Lipid Array 345 13.4 Fabrication of Nanoscale Topographies for Tissue Engineering Applications 347 13.4.1 Nanotopography-Induced Changes in Cell Adhesion 347 13.4.2 Nanotopography-Induced Changes in Cell Morphology 348 References 349 14 MICRO TOTAL ANALYSIS SYSTEM 359 Yuki Tanaka and Takehiko Kitamori 14.1 Introduction 359 14.1.1 Historical Backgrounds 359 14.2 Fundamentals on Microchip Chemistry 361 14.2.1 Characteristics of Liquid Microspace 361 14.2.2 Liquid Handling 362 14.2.3 Concepts of Micro Unit Operation and Continuous-Flow Chemical Processing 362 14.3 Key Technologies 365 14.3.1 Fabrication of Microchips 365 14.3.2 Patterning for Fluid Control 366 14.3.3 Detection 366 14.4 Applications 368 14.4.1 Synthesis 368 14.4.2 Cell Adhesion Control 369 14.4.3 Liquid Handling: Valve Using Wettability 370 References 372 15 COMBINATIONS OF TOP-DOWN AND BOTTOM-UP NANOFABRICATION TECHNIQUES AND THEIR APPLICATION TO CREATE FUNCTIONAL DEVICES 379 Pascale Maury, David N. Reinhoudt, and Jurriaan Huskens 15.1 Introduction 379 15.2 Top-Down and Bottom-Up Techniques 380 15.2.1 Top-Down Techniques 380 15.2.2 Bottom-Up Techniques 383 15.2.3 Mixed Techniques 384 15.3 Combining Top-Down and Bottom-Up Techniques for High Resolution Patterning 385 15.3.1 Top-Down Nanofabrication and Polymerization 386 15.3.2 Top-Down Nanofabrication and Micelles 387 15.3.3 Top-Down Nanofabrication and Block Copolymer Assembly 387 15.3.4 Top-Down Nanofabrication and NP Assembly 389 15.3.5 Top-Down Nanofabrication and Layer-by-Layer Assembly 392 15.4 Applicaion of Combined Top-Down and Bottom-Up Nanofabrication for Creating Functional Devices 397 15.4.1 Photonic Crystal Devices 397 15.4.2 Protein Assays 400 References 406 16 ORGANIC ELECTRONIC DEVICES 419 16.1 Introduction 419 16.2 Organic Light-Emitting Diodes 420 16.3 Organic Thin Film Transistors 429 References 439 17 INORGANIC ELECTRONIC DEVICES 445 17.1 Introduction 445 17.2 Inorganic Semiconductor Materials for Flexible Electronics 446 17.2.1 “Bottom-Up” Approaches 447 17.2.2 “Top-Down” Approaches 449 17.3 Soft Lithography Techniques for Generating Inorganic Electronic Systems 452 17.3.1 Micromolding in Capillaries 453 17.3.2 Imprint Lithography 454 17.3.3 Dry Transfer Printing 454 17.4 Fabrication of Electronic Devices 459 17.4.1 Transistors on Rigid Substrates via MIMIC Processing 459 17.4.2 Flexible Inorganic Transistors 459 17.4.3 Flexible Integrated Circuits 463 17.4.4 Heterogeneous Electronics 466 17.4.5 Stretchable Electronics 469 References 475 18 MECHANICS OF STRETCHABLE SILICON FILMS ON ELASTOMERIC SUBSTRATES 483 Hanqing Jiang, Jizhou Song, Yonggang Huang, and John A. Rogers 18.1 Introduction 483 18.2 Buckling Analysis of Stiff Thin Ribbons on Compliant Substrates 484 18.3 Finite-Deformation Buckling Analysis of Stiff Thin Ribbons on Compliant Substrates 488 18.4 Edge Effects 495 18.5 Effect of Ribbon Width and Spacing 498 18.6 Buckling Analysis of Stiff Thin Membranes on Compliant Substrates 502 18.6.1 One-Dimensional Buckling Mode 504 18.6.2 Checkerboard Buckling Mode 506 18.6.3 Herrington Buckling Mode 506 18.7 Precisely Controlled Buckling of Stiff Thin Ribbons on Compliant Substrates 507 18.8 Concluding Remarks 512 Acknowledgments 512 References 512 19 MULTISCALE FABRICATION OF PLASMONIC STRUCTURES 515 Joel Henzie, Min H. Lee, and Teri W. Odom 19.1 Introduction 515 19.1.1 Brief Primer on Surface Plasmons 517 19.1.2 Conventional Methods to Plasmonic Structures 518 19.2 Soft Lithography and Metal Nanostructures 518 19.3 A Platform for Multiscale Patterning 520 19.3.1 Soft Interference Lithography: Patterns on a Nanoscale Pitch 520 19.3.2 Phase-Shifting Photolithography: Patterns on a Microscale Pitch 520 19.3.3 PEEL: Transferring Photoresist Patterns to Plasmonic Materials 521 19.4 Subwavelength Arrays of Nanoholes: Plasmonic Materials 522 19.4.1 Infinite Arrays of Nanoholes 523 19.4.2 Finite Arrays (Patches) of Nanoholes 525 19.5 Microscale Arrays of Nanoscale Holes 526 19.6 Plasmonic Particle Arrays 528 19.6.1 Metal and Dielectric Nanoparticles 528 19.6.2 Anisotropic Nanoparticles 531 19.6.3 Pyramidal Nanostructures 531 Acknowledgments 533 References 533 20 A RIGIFLEX MOLD AND ITS APPLICATIONS 539 Se-Jin Choi, Tae-Wan Kim, and Seung-Jun Baek 20.1 Introduction 539 20.2 Modulus-Tunable Rigiflex Mold 540 20.3 Applications of Rigiflex Mold 544 20.3.1 From Nanoimprint to Microcontact Printing 544 20.3.2 Rapid Flash Patterning for Residue-Free Patterning 547 20.3.3 Continuous Rigiflex Imprinting 549 20.3.4 Soft Molding Application 553 20.3.5 Capillary Force Lithography Applications 556 20.3.6 Transfer Fabrication Technique 558 References 561 21 NANOIMPRINT TECHNOLOGY FOR FUTURE LIQUID CRYSTAL DISPLAY 565 Jong M. Kim, Hwan Y. Choi, Moon-G. Lee, Seungho Nam, Jin H. Kim, Seongmo Whang, Soo M. Lee, Byoung H. Cheong, Hyuk Kim, Ji M. Lee, and In T. Han 21.1 Introduction 565 21.2 Holographic LGP 569 21.2.1 Design and Properties of Holographic LGP 570 21.2.2 NI Technology for the Holographic LGP 572 21.3 Polarized LGP 573 21.3.1 Design and Properties of Polarized LGP 574 21.3.2 Fabrication of the Polarized LGP 575 21.3.3 Optical Performance of the Polarized LGP 576 21.4 Reflective Polarizer: Wire Grid Polarizer 579 21.4.1 Design and Properies of WGP 580 21.4.2 Fabrication and Applications 581 21.5 Transflective Display 585 21.5.1 Design and Optical Properties of Reflecting Pattern 587 21.5.2 Fabrication of the Reflecting Pattern 588 References 592 INDEX 595