XINWEI WANG, PHD, is a Full Professor in the Department of Mechanical Engineering at Iowa State University, where he is also the Director of the Micro/Nanoscale Thermal Science Laboratory. His current research focuses on SPM-based thermal probing and thermal transport in biomaterials.

• Preface xi1 Introduction 11.1 Unique Feature of Thermal Transport in Nanoscale and Nanostructured Materials 11.1.1 Thermal Transport Constrained by Material Size 21.1.2 Thermal Transport Constrained by Time 61.1.3 Thermal Transport Constrained by the Size of Physical Process 81.2 Molecular Dynamics Simulation of Thermal Transport at Micro/Nanoscales 101.2.1 Equilibrium MD Prediction of Thermal Conductivity 111.2.2 Nonequilibrium MD Study of Thermal Transport 151.2.3 MD Study of Thermal Transport Constrained by Time 181.3 Boltzmann Transportation Equation for Thermal Transport Study 211.4 Direct Energy Carrier Relaxation Tracking (DECRT) 321.5 Challenges in Characterizing Thermal Transport at Micro/Nanoscales 44References 452 Thermal Characterization in Frequency Domain 472.1 Frequency Domain Photoacoustic (PA) Technique 472.1.1 Physical Model 482.1.2 Experimental Details 502.1.3 PA Measurement of Films and Bulk Materials 522.1.4 Uncertainty of the PA Measurement 552.2 Frequency Domain Photothermal Radiation (PTR) Technique 572.2.1 Experimental Details of the PTR Technique 572.2.2 PTR Measurement of Micrometer-Thick Films 582.2.3 PTR with Internal Heating of Desired Locations 602.3 Three-Omega Technique 622.3.1 Physical Model of the 3ω Technique for One-Dimensional Structures 622.3.2 Experimental Details 652.3.3 Calibration of the Experiment 672.3.4 Measurement of Micrometer-Thick Wires 692.3.5 Effect of Radiation on Measurement Result 702.4 Optical Heating Electrical Thermal Sensing (OHETS) Technique 732.4.1 Experimental Principle and Physical Model 732.4.2 Effect of Nonuniform Distribution of Laser Beam 742.4.3 Experimental Details and Calibration 772.4.4 Measurement of Electrically Conductive Wires 792.4.5 Measurement of Nonconductive Wires 812.4.6 Effect of Au Coating on Measurement 832.4.7 Temperature Rise in the OHETS Experiment 842.5 Comparison Among the Techniques 85References 863 Transient Technologies in the Time Domain 873.1 Transient Photo-Electro-Thermal (TPET) Technique 873.1.1 Experimental Principles 883.1.2 Physical Model Development 883.1.3 Effect of Nonuniform Distribution and Finite Rising Time of the Laser Beam 903.1.4 Experimental Setup 923.1.5 Technique Validation 933.1.6 Thermal Characterization of SWCNT Bundles and Cloth Fibers 953.2 Transient Electrothermal (TET) Technique 983.2.1 Physical Principles of the TET Technique 983.2.2 Methods for Data Analysis to Determine the Thermal Diffusivity 1003.2.3 Effect of Nonconstant Electrical Heating 1013.2.4 Experimental Details 1023.2.5 Technique Validation 1043.2.6 Measurement of SWCNT Bundles 1053.2.7 Measurement of Polyester Fibers 1073.2.8 Measurement of Micro/Submicroscale Polyacrylonitrile Wires 1093.3 Pulsed Laser-Assisted Thermal Relaxation Technique 1133.3.1 Experimental Principles 1133.3.2 Physical Model for the PLTR Technique 1143.3.3 Methods to Determine the Thermal Diffusivity 1163.3.4 Experimental Setup and Technique Validation 1173.3.5 Measurement of Multiwalled Carbon Nanotube (MWCNT) Bundles 1183.3.6 Measurement of Individual Microscale Carbon Fibers 1223.4 Super Channeling Effect for Thermal Transport in Micro/Nanoscale Wires 1233.5 Multidimensional Thermal Characterization 1283.5.1 Sample Preparation 1293.5.2 Thermal Characterization Design 1303.5.3 Thermal Transport Along the Axial Direction of Amorphous TiO2 Nanotubes 1313.5.4 Thermal Transport in the Cross-Tube Direction of Amorphous TiO2 Nanotubes 1333.5.5 Evaluation of Thermal Contact Resistance Between Amorphous TiO2 Nanotubes 1363.5.6 Anisotropic Thermal Transport in Anatase TiO2 Nanotubes 1373.6 Remarks on the Transient Technologies 139References 1394 Steady-State Thermal Characterization 1414.1 Generalized Electrothermal Characterization 1424.1.1 Generalized Electrothermal (GET) Technique: Combined Transient and Steady States 1424.1.2 Experimental Setup 1444.1.3 Experimental Details 1454.1.4 Measurement of MWCNT Bundle with L = 3.33 mm and D = 94.5 μm 1474.1.5 Measurement of MWCNT Bundle with L = 2.90 mm and D = 233 μm 1534.1.6 Analysis of the Tube-to-Tube Thermal Contact Resistance 1574.1.7 Effect of Radiation Heat Loss 1584.2 Get Measurement of Porous Freestanding Thin Films Composed of Anatase TiO2 Nanofibers 1594.2.1 Sample Preparation 1604.2.2 R–T Calibration 1624.2.3 TET Measurement of Thermal Conductivity and Thermal Diffusivity 1634.2.4 Thermophysical Properties of Samples with Different Dimensions 1674.2.5 The Intrinsic Thermal Conductivity of TiO2 Nanofibers 1704.2.6 Uncertainty Analysis 1724.3 Measurement of Micrometer-Thick Polymer Films 1734.3.1 Sample Preparation 1734.3.2 Electrical Resistance (R)-Temperature Coefficient Calibration 1754.3.3 Measurement of Thermal Conductivity and Thermal Diffusivity 1754.3.4 Thermophysical Properties of P3HT Thin Films with Different Dimensions 1784.4 Steady-State Electro-Raman Thermal (SERT) Technique 1824.4.1 Experimental Principle and Physical Model Development 1834.4.2 Experimental Setup for Measuring CNT Buckypaper 1874.4.3 Calibration Experiment 1884.4.4 Thermal Characterization of MWCNT Buckypapers 1904.4.5 Thermal Conductivity Analysis 1924.4.6 Uncertainty Induced by Location of Laser Focal Point 1954.4.7 Effect of Thermal and Electrical Contact Resistances and Thermal Transport in Electrodes 1964.5 SERT Measurement of MWCNT Bundles 1974.6 Extension of the Steady-State Techniques 202References 2025 Steady-State Optical-Based Thermal Probing and Characterization 2055.1 Sub-10-nm Temperature Measurement 2055.1.1 Introduction to Sub-10-nm Near-Field Focusing 2065.1.2 Experimental Design and Conduction 2085.1.3 Measurement Results 2105.1.4 Physics Behind Near-Field Focusing and Thermal Transport 2135.2 Thermal Probing at nm/SUB-nm Resolution for Studying Interface Thermal Transport 2195.2.1 Introduction 2195.2.2 Experimental Method 2205.2.3 Experimental Results 2215.2.4 Comparison with Molecular Dynamics Simulation 2255.2.5 Discussion 2265.3 Optical Heating and Thermal Sensing using Raman Spectrometer 2345.3.1 Thermal Conductivity Measurement of Suspended Filmlike Materials 2345.3.2 Thermal Conductivity Measurement of Suspended Nanowires 2365.4 Bilayer Sensor-Based Technique 2375.5 Further Consideration for Micro/Nanoscale Thermal Sensing and Characterization 2385.5.1 Electrothermal Sensing in Thermal Characterization of Coatings/Films 2395.5.2 Transient Photo-Heating and Thermal Sensing of Wirelike Samples 240References 242Index 247

“Experimentalists measuring thermal transport properties of micro-or nanoscale materials will definitely find this book well worth their time.”  (IEEE Electrical Insulation Magazine, 1 September 2013

XINWEI WANG, PHD, is a Full Professor in the Department of Mechanical Engineering at Iowa State University, where he is also the Director of the Micro/Nanoscale Thermal Science Laboratory. His current research focuses on SPM-based thermal probing and thermal transport in biomaterials.

• Preface xi1 Introduction 11.1 Unique Feature of Thermal Transport in Nanoscale and Nanostructured Materials 11.1.1 Thermal Transport Constrained by Material Size 21.1.2 Thermal Transport Constrained by Time 61.1.3 Thermal Transport Constrained by the Size of Physical Process 81.2 Molecular Dynamics Simulation of Thermal Transport at Micro/Nanoscales 101.2.1 Equilibrium MD Prediction of Thermal Conductivity 111.2.2 Nonequilibrium MD Study of Thermal Transport 151.2.3 MD Study of Thermal Transport Constrained by Time 181.3 Boltzmann Transportation Equation for Thermal Transport Study 211.4 Direct Energy Carrier Relaxation Tracking (DECRT) 321.5 Challenges in Characterizing Thermal Transport at Micro/Nanoscales 44References 452 Thermal Characterization in Frequency Domain 472.1 Frequency Domain Photoacoustic (PA) Technique 472.1.1 Physical Model 482.1.2 Experimental Details 502.1.3 PA Measurement of Films and Bulk Materials 522.1.4 Uncertainty of the PA Measurement 552.2 Frequency Domain Photothermal Radiation (PTR) Technique 572.2.1 Experimental Details of the PTR Technique 572.2.2 PTR Measurement of Micrometer-Thick Films 582.2.3 PTR with Internal Heating of Desired Locations 602.3 Three-Omega Technique 622.3.1 Physical Model of the 3ω Technique for One-Dimensional Structures 622.3.2 Experimental Details 652.3.3 Calibration of the Experiment 672.3.4 Measurement of Micrometer-Thick Wires 692.3.5 Effect of Radiation on Measurement Result 702.4 Optical Heating Electrical Thermal Sensing (OHETS) Technique 732.4.1 Experimental Principle and Physical Model 732.4.2 Effect of Nonuniform Distribution of Laser Beam 742.4.3 Experimental Details and Calibration 772.4.4 Measurement of Electrically Conductive Wires 792.4.5 Measurement of Nonconductive Wires 812.4.6 Effect of Au Coating on Measurement 832.4.7 Temperature Rise in the OHETS Experiment 842.5 Comparison Among the Techniques 85References 863 Transient Technologies in the Time Domain 873.1 Transient Photo-Electro-Thermal (TPET) Technique 873.1.1 Experimental Principles 883.1.2 Physical Model Development 883.1.3 Effect of Nonuniform Distribution and Finite Rising Time of the Laser Beam 903.1.4 Experimental Setup 923.1.5 Technique Validation 933.1.6 Thermal Characterization of SWCNT Bundles and Cloth Fibers 953.2 Transient Electrothermal (TET) Technique 983.2.1 Physical Principles of the TET Technique 983.2.2 Methods for Data Analysis to Determine the Thermal Diffusivity 1003.2.3 Effect of Nonconstant Electrical Heating 1013.2.4 Experimental Details 1023.2.5 Technique Validation 1043.2.6 Measurement of SWCNT Bundles 1053.2.7 Measurement of Polyester Fibers 1073.2.8 Measurement of Micro/Submicroscale Polyacrylonitrile Wires 1093.3 Pulsed Laser-Assisted Thermal Relaxation Technique 1133.3.1 Experimental Principles 1133.3.2 Physical Model for the PLTR Technique 1143.3.3 Methods to Determine the Thermal Diffusivity 1163.3.4 Experimental Setup and Technique Validation 1173.3.5 Measurement of Multiwalled Carbon Nanotube (MWCNT) Bundles 1183.3.6 Measurement of Individual Microscale Carbon Fibers 1223.4 Super Channeling Effect for Thermal Transport in Micro/Nanoscale Wires 1233.5 Multidimensional Thermal Characterization 1283.5.1 Sample Preparation 1293.5.2 Thermal Characterization Design 1303.5.3 Thermal Transport Along the Axial Direction of Amorphous TiO2 Nanotubes 1313.5.4 Thermal Transport in the Cross-Tube Direction of Amorphous TiO2 Nanotubes 1333.5.5 Evaluation of Thermal Contact Resistance Between Amorphous TiO2 Nanotubes 1363.5.6 Anisotropic Thermal Transport in Anatase TiO2 Nanotubes 1373.6 Remarks on the Transient Technologies 139References 1394 Steady-State Thermal Characterization 1414.1 Generalized Electrothermal Characterization 1424.1.1 Generalized Electrothermal (GET) Technique: Combined Transient and Steady States 1424.1.2 Experimental Setup 1444.1.3 Experimental Details 1454.1.4 Measurement of MWCNT Bundle with L = 3.33 mm and D = 94.5 μm 1474.1.5 Measurement of MWCNT Bundle with L = 2.90 mm and D = 233 μm 1534.1.6 Analysis of the Tube-to-Tube Thermal Contact Resistance 1574.1.7 Effect of Radiation Heat Loss 1584.2 Get Measurement of Porous Freestanding Thin Films Composed of Anatase TiO2 Nanofibers 1594.2.1 Sample Preparation 1604.2.2 R–T Calibration 1624.2.3 TET Measurement of Thermal Conductivity and Thermal Diffusivity 1634.2.4 Thermophysical Properties of Samples with Different Dimensions 1674.2.5 The Intrinsic Thermal Conductivity of TiO2 Nanofibers 1704.2.6 Uncertainty Analysis 1724.3 Measurement of Micrometer-Thick Polymer Films 1734.3.1 Sample Preparation 1734.3.2 Electrical Resistance (R)-Temperature Coefficient Calibration 1754.3.3 Measurement of Thermal Conductivity and Thermal Diffusivity 1754.3.4 Thermophysical Properties of P3HT Thin Films with Different Dimensions 1784.4 Steady-State Electro-Raman Thermal (SERT) Technique 1824.4.1 Experimental Principle and Physical Model Development 1834.4.2 Experimental Setup for Measuring CNT Buckypaper 1874.4.3 Calibration Experiment 1884.4.4 Thermal Characterization of MWCNT Buckypapers 1904.4.5 Thermal Conductivity Analysis 1924.4.6 Uncertainty Induced by Location of Laser Focal Point 1954.4.7 Effect of Thermal and Electrical Contact Resistances and Thermal Transport in Electrodes 1964.5 SERT Measurement of MWCNT Bundles 1974.6 Extension of the Steady-State Techniques 202References 2025 Steady-State Optical-Based Thermal Probing and Characterization 2055.1 Sub-10-nm Temperature Measurement 2055.1.1 Introduction to Sub-10-nm Near-Field Focusing 2065.1.2 Experimental Design and Conduction 2085.1.3 Measurement Results 2105.1.4 Physics Behind Near-Field Focusing and Thermal Transport 2135.2 Thermal Probing at nm/SUB-nm Resolution for Studying Interface Thermal Transport 2195.2.1 Introduction 2195.2.2 Experimental Method 2205.2.3 Experimental Results 2215.2.4 Comparison with Molecular Dynamics Simulation 2255.2.5 Discussion 2265.3 Optical Heating and Thermal Sensing using Raman Spectrometer 2345.3.1 Thermal Conductivity Measurement of Suspended Filmlike Materials 2345.3.2 Thermal Conductivity Measurement of Suspended Nanowires 2365.4 Bilayer Sensor-Based Technique 2375.5 Further Consideration for Micro/Nanoscale Thermal Sensing and Characterization 2385.5.1 Electrothermal Sensing in Thermal Characterization of Coatings/Films 2395.5.2 Transient Photo-Heating and Thermal Sensing of Wirelike Samples 240References 242Index 247

“Experimentalists measuring thermal transport properties of micro-or nanoscale materials will definitely find this book well worth their time.”  (IEEE Electrical Insulation Magazine, 1 September 2013

XINWEI WANG, PHD, is a Full Professor in the Department of Mechanical Engineering at Iowa State University, where he is also the Director of the Micro/Nanoscale Thermal Science Laboratory. His current research focuses on SPM-based thermal probing and thermal transport in biomaterials.

• Preface xi1 Introduction 11.1 Unique Feature of Thermal Transport in Nanoscale and Nanostructured Materials 11.1.1 Thermal Transport Constrained by Material Size 21.1.2 Thermal Transport Constrained by Time 61.1.3 Thermal Transport Constrained by the Size of Physical Process 81.2 Molecular Dynamics Simulation of Thermal Transport at Micro/Nanoscales 101.2.1 Equilibrium MD Prediction of Thermal Conductivity 111.2.2 Nonequilibrium MD Study of Thermal Transport 151.2.3 MD Study of Thermal Transport Constrained by Time 181.3 Boltzmann Transportation Equation for Thermal Transport Study 211.4 Direct Energy Carrier Relaxation Tracking (DECRT) 321.5 Challenges in Characterizing Thermal Transport at Micro/Nanoscales 44References 452 Thermal Characterization in Frequency Domain 472.1 Frequency Domain Photoacoustic (PA) Technique 472.1.1 Physical Model 482.1.2 Experimental Details 502.1.3 PA Measurement of Films and Bulk Materials 522.1.4 Uncertainty of the PA Measurement 552.2 Frequency Domain Photothermal Radiation (PTR) Technique 572.2.1 Experimental Details of the PTR Technique 572.2.2 PTR Measurement of Micrometer-Thick Films 582.2.3 PTR with Internal Heating of Desired Locations 602.3 Three-Omega Technique 622.3.1 Physical Model of the 3ω Technique for One-Dimensional Structures 622.3.2 Experimental Details 652.3.3 Calibration of the Experiment 672.3.4 Measurement of Micrometer-Thick Wires 692.3.5 Effect of Radiation on Measurement Result 702.4 Optical Heating Electrical Thermal Sensing (OHETS) Technique 732.4.1 Experimental Principle and Physical Model 732.4.2 Effect of Nonuniform Distribution of Laser Beam 742.4.3 Experimental Details and Calibration 772.4.4 Measurement of Electrically Conductive Wires 792.4.5 Measurement of Nonconductive Wires 812.4.6 Effect of Au Coating on Measurement 832.4.7 Temperature Rise in the OHETS Experiment 842.5 Comparison Among the Techniques 85References 863 Transient Technologies in the Time Domain 873.1 Transient Photo-Electro-Thermal (TPET) Technique 873.1.1 Experimental Principles 883.1.2 Physical Model Development 883.1.3 Effect of Nonuniform Distribution and Finite Rising Time of the Laser Beam 903.1.4 Experimental Setup 923.1.5 Technique Validation 933.1.6 Thermal Characterization of SWCNT Bundles and Cloth Fibers 953.2 Transient Electrothermal (TET) Technique 983.2.1 Physical Principles of the TET Technique 983.2.2 Methods for Data Analysis to Determine the Thermal Diffusivity 1003.2.3 Effect of Nonconstant Electrical Heating 1013.2.4 Experimental Details 1023.2.5 Technique Validation 1043.2.6 Measurement of SWCNT Bundles 1053.2.7 Measurement of Polyester Fibers 1073.2.8 Measurement of Micro/Submicroscale Polyacrylonitrile Wires 1093.3 Pulsed Laser-Assisted Thermal Relaxation Technique 1133.3.1 Experimental Principles 1133.3.2 Physical Model for the PLTR Technique 1143.3.3 Methods to Determine the Thermal Diffusivity 1163.3.4 Experimental Setup and Technique Validation 1173.3.5 Measurement of Multiwalled Carbon Nanotube (MWCNT) Bundles 1183.3.6 Measurement of Individual Microscale Carbon Fibers 1223.4 Super Channeling Effect for Thermal Transport in Micro/Nanoscale Wires 1233.5 Multidimensional Thermal Characterization 1283.5.1 Sample Preparation 1293.5.2 Thermal Characterization Design 1303.5.3 Thermal Transport Along the Axial Direction of Amorphous TiO2 Nanotubes 1313.5.4 Thermal Transport in the Cross-Tube Direction of Amorphous TiO2 Nanotubes 1333.5.5 Evaluation of Thermal Contact Resistance Between Amorphous TiO2 Nanotubes 1363.5.6 Anisotropic Thermal Transport in Anatase TiO2 Nanotubes 1373.6 Remarks on the Transient Technologies 139References 1394 Steady-State Thermal Characterization 1414.1 Generalized Electrothermal Characterization 1424.1.1 Generalized Electrothermal (GET) Technique: Combined Transient and Steady States 1424.1.2 Experimental Setup 1444.1.3 Experimental Details 1454.1.4 Measurement of MWCNT Bundle with L = 3.33 mm and D = 94.5 μm 1474.1.5 Measurement of MWCNT Bundle with L = 2.90 mm and D = 233 μm 1534.1.6 Analysis of the Tube-to-Tube Thermal Contact Resistance 1574.1.7 Effect of Radiation Heat Loss 1584.2 Get Measurement of Porous Freestanding Thin Films Composed of Anatase TiO2 Nanofibers 1594.2.1 Sample Preparation 1604.2.2 R–T Calibration 1624.2.3 TET Measurement of Thermal Conductivity and Thermal Diffusivity 1634.2.4 Thermophysical Properties of Samples with Different Dimensions 1674.2.5 The Intrinsic Thermal Conductivity of TiO2 Nanofibers 1704.2.6 Uncertainty Analysis 1724.3 Measurement of Micrometer-Thick Polymer Films 1734.3.1 Sample Preparation 1734.3.2 Electrical Resistance (R)-Temperature Coefficient Calibration 1754.3.3 Measurement of Thermal Conductivity and Thermal Diffusivity 1754.3.4 Thermophysical Properties of P3HT Thin Films with Different Dimensions 1784.4 Steady-State Electro-Raman Thermal (SERT) Technique 1824.4.1 Experimental Principle and Physical Model Development 1834.4.2 Experimental Setup for Measuring CNT Buckypaper 1874.4.3 Calibration Experiment 1884.4.4 Thermal Characterization of MWCNT Buckypapers 1904.4.5 Thermal Conductivity Analysis 1924.4.6 Uncertainty Induced by Location of Laser Focal Point 1954.4.7 Effect of Thermal and Electrical Contact Resistances and Thermal Transport in Electrodes 1964.5 SERT Measurement of MWCNT Bundles 1974.6 Extension of the Steady-State Techniques 202References 2025 Steady-State Optical-Based Thermal Probing and Characterization 2055.1 Sub-10-nm Temperature Measurement 2055.1.1 Introduction to Sub-10-nm Near-Field Focusing 2065.1.2 Experimental Design and Conduction 2085.1.3 Measurement Results 2105.1.4 Physics Behind Near-Field Focusing and Thermal Transport 2135.2 Thermal Probing at nm/SUB-nm Resolution for Studying Interface Thermal Transport 2195.2.1 Introduction 2195.2.2 Experimental Method 2205.2.3 Experimental Results 2215.2.4 Comparison with Molecular Dynamics Simulation 2255.2.5 Discussion 2265.3 Optical Heating and Thermal Sensing using Raman Spectrometer 2345.3.1 Thermal Conductivity Measurement of Suspended Filmlike Materials 2345.3.2 Thermal Conductivity Measurement of Suspended Nanowires 2365.4 Bilayer Sensor-Based Technique 2375.5 Further Consideration for Micro/Nanoscale Thermal Sensing and Characterization 2385.5.1 Electrothermal Sensing in Thermal Characterization of Coatings/Films 2395.5.2 Transient Photo-Heating and Thermal Sensing of Wirelike Samples 240References 242Index 247

“Experimentalists measuring thermal transport properties of micro-or nanoscale materials will definitely find this book well worth their time.”  (IEEE Electrical Insulation Magazine, 1 September 2013