Research Topics

Time and Rate Dependent Fracture of Materials and Interfaces
Nonlinear Mechanics of Hydrogels and Soft Materials
Mechanics of Graphene and 2D Materials
Thermomechanical Reliability in Advanced Packaging and 3D Integration
Buckling of Nanostructures
Wrinkling of Thin Films on Soft Substrates
Surface Morphological Evolution and Self-Assembly of Quantum Dots
Stress Relaxation and Interface Diffusion in Copper Interconnects
Fracture in Thin-Film Structures
Strain-Relaxed SiGe Islands on Oxides
Deformation Mechanisms in Metallic Glasses
Theory and Applications of Mechanical Resonators

Time and Rate Dependent Fracture of Materials and Interfaces

Collaborators: Chad Landis (UT) and Kenneth M. Liechti (UT)
Funding: NSF and SRC

Presentation slides:

Publications:

T. Yang, V. Gandhi, R. Huang, K.M. Liechti, Rate Dependent Fracture along a Silicon/Epoxy Interface under Mixed-Mode Loading Conditions. International Journal of Solids and Structures 257, 111129 (2022). DOI
T. Yang, K.M. Liechti, R. Huang, A multiscale cohesive zone model for rate-dependent fracture of interfaces. J. Mech. Phys. Solids 145, 104142 (2020). DOI
Y. Yu, C.M. Landis, R. Huang, Poroelastic effects on steady state crack growth in polymer gels under plane stress. Mechanics of Materials 143, 103320 (2020). DOI
Y. Yu, N. Bouklas, C.M. Landis, R. Huang, Poroelastic effects on the time and rate dependent fracture of polymer gels. J. Appl. Mech. 87, 031005 (2020). DOI
C. Xu, T. Yang, Y. Kang, Q. Li, T. Xue, K.M. Liechti, R. Huang, W. Qiu, Rate-dependent decohesion modes in graphene sandwiched interfaces. Advanced Materials Interfaces, 1901217 (2019). DOI
T. Yang, X. Yang, R. Huang, K.M. Liechti, Rate-dependent traction-separation relations for a silicon/epoxy interface informed by experiments and bond rupture kinetics. J. Mech. Phys. Solids 131, 1-19 (2019). DOI: 10.1016/j.jmps.2019.06.013.
Y. Yu, N. Bouklas, C.M. Landis, R. Huang, A Linear Poroelastic Analysis of Time-Dependent Crack-Tip Fields in Polymer Gels. J. Appl. Mech. 85, no.111011 (2018). DOI: 10.1115/1.4041040.
Y. Yu, C.M. Landis, R. Huang, Steady-State Crack Growth in Polymer Gels: A Linear Poroelastic Analysis. J. Mech. Phys. Solids 118, 15-39 (2018).

Nonlinear Mechanics of Hydrogels and Soft Materials

Collaborators: Chad Landis (UT) and K. Ravi-Chandar (UT)
Funding: National Science Foundation

Presentation slides:

Large Deformation of Hydrogels Coupled with Solvent Diffusion, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, August 4, 2015.
Swell Induced Surface Instability in Substrate-Confined Hydrogel Layers, Materials Research Society Fall Meeting, Boston, MA. November 29, 2010.

Publications:

S. Hao, R. Huang, G.J. Rodin, Constitutive models for confined elastomeric layers: Effects of nonlinearity and compressibility. Mechanics of Materials 190, 104912 (2024). DOI
A. Arrowood, M. A. Ansari, M. Ciccotti, R. Huang, K. M. Liechti, G. E. Sanoja, Understanding the role of crosslink density and linear viscoelasticity on the shear failure of pressure-sensitive-adhesives. Soft Matter 19, 6088-6096 (2023). DOI
S. Hao, Z. Suo, R. Huang, Why does an elastomer layer confined between two rigid blocks grow numerous cavities? J. Mech. Phys. Solids 173, 105223 (2023). DOI.
C.M. Landis, R. Huang, J.W. Hutchinson, Formation of surface wrinkles and creases in constrained dielectric elastomers subject to electromechanical loading. J. Mech. Phys. Solids 167, 105023 (2022). DOI
C. Lang, E. C. Lloyd, K. E. Matuszewski, Y. Xu, V. Ganesan, R. Huang, M. Kumar, R. J. Hickey, Nanostructured Block Copolymer Muscles.
Nature Nanotechnology 17, 752-758 (2022). DOI Share link (free access)
J.W. Hutchinson, R. Huang, C.M. Landis, Errata: Surface instabilities of constrained elastomeric layers subject to electro-static stressing by J. W. Hutchinson, J. Mech. Phys. Solids 153 (2021) 104462. J. Mech. Phys. Solids 160, 104809 (2022). DOI.
S. Chen, R. Huang, K. Ravi-Chandar, Linear and nonlinear poroelastic analysis of swelling and drying behavior of gelatin-based hydrogels. International Journal of Solids and Structures 195, 43-56 (2020). DOI
Y. Yu, C.M. Landis, R. Huang, Poroelastic effects on steady state crack growth in polymer gels under plane stress. Mechanics of Materials 143, 103320 (2020). DOI
Y. Yu, N. Bouklas, C.M. Landis, R. Huang, Poroelastic effects on the time and rate dependent fracture of polymer gels. J. Appl. Mech. 87, 031005 (2020). DOI
Y. Yu, N. Bouklas, C.M. Landis, R. Huang, A Linear Poroelastic Analysis of Time-Dependent Crack-Tip Fields in Polymer Gels. J. Appl. Mech. 85, no.111011 (2018). DOI: 10.1115/1.4041040.
Y. Yu, C.M. Landis, R. Huang, Steady-State Crack Growth in Polymer Gels: A Linear Poroelastic Analysis. J. Mech. Phys. Solids 118, 15-39 (2018).
Y. Yu, C.M. Landis, R. Huang, Salt-induced Swelling and Volume Phase Transition of Polyel ectrolyte Gels. Journal of Applied Mechanics 84, 051005 (2017). DOI: 10.1115/1.4036113.
P. Wang, W. Gao, J. Wilkerson, K. M. Liechti and R. Huang, Cavitation of water by volume-controlled stretching. Extreme Mechanics Letters 11, 59-67 (2017). DOI: 10.1016/j.eml.2016.12.004. Preprint at arXiv:1609.07187.
Z. Wu, N. Bouklas, Y. Liu, R. Huang, Onset of swell-induced surface instability of hydrogel layers with depth-wise graded material properties. Mechanics of Materials 105, 138-147 (2017).
N. Bouklas, C.M. Landis, R. Huang, Effect of solvent diffusion on crack-tip fields and driving force for fracture of hydrogels. Journal of Applied Mechanics 82, 081007 (2015). DOI: 10.1115/1.4030587.
N. Bouklas, C.M. Landis, R. Huang, A nonlinear, transient finite element method for coupled solvent diffusion and large deformation of hydrogels. J. Mech. Phys. Solids 79, 21-43 (2015). DOI: 10.1016/j.jmps.2015.03.004.
S. Chatterjee, C. McDonald, J. Niu, S. Velankar, P. Wang, R. Huang, Wrinkling and folding of thin films by viscous stress. Soft Matter 11, 1814-1827 (2015). DOI: 10.1039/C4SM02501F.
Z. Wu, J. Meng, Y. Liu, H. Li, R. Huang, A state space method for surface instability of elastic layers with material properties varying in thickness direction. Journal of Applied Mechanics 81, 081003 (2014).
V. Nayyar, K. Ravi-Chandar, R. Huang, Stretch-induced wrinkling of polyethylene thin sheets: experiments and modeling. International Journal of Solids and Structures 51, 1847-1858 (2014). DOI: 10.1016/j.ijsolstr.2014.01.028
F. Weiss, S. Cai, Y. Hu, M. K. Kang, R. Huang, Z. Suo, Creases and wrinkles on the surface of a swollen gel. J. Applied Physics 114, 073507 (2013).
Z. Wu, N. Bouklas, R. Huang, Swell-induced surface instability of hydrogel layers with material properties varying in thickness direction. Int. J. Solids and Structures 50, 578-587 (2013). DOI: 10.1016/j.ijsolstr.2012.10.022.
N. Bouklas and R. Huang, Swelling kinetics of polymer gels: comparison of linear and nonlinear theories. Soft Matter 8, 8194-8203 (2012). DOI: 10.1039/C2SM25467K.
T. Lu, J. Huang, C. Jordi, G. Kovacs, R. Huang, D.R. Clarke, Z. Suo, Dielectric elastomer actuators under equi-biaxial forces, uniaxial forces, and uniaxial constraint of stiff fibers. Soft Matter 8, 6167-6173 (2012). DOI: 10.1039/c2sm25692d.
R. Huang and Z. Suo, Electromechanical phase transition in dielectric elastomers. Proc. Royal Soc. A 468, 1014-1040 (2012). DOI: 10.1098/rspa.2011.0452.
V. Nayyar, K. Ravi-Chandar, R. Huang, Stretch-induced stress patterns and wrinkles in hyperelastic thin sheets. International Journal of Solids and Structures 48, 3471-3483 (2011). DOI: 10.1016/j.ijsolstr.2011.09.004.
M.K. Kang and R. Huang, Swell-induced instability of substrate-attached hydrogel lines. Int. J. Applied Mechanics 3, 219-233 (2011). DOI: 10.1142/S1758825111000956.
M. Caldorera-Moore, M.K. Kang, Z. Moore, V. Singh, S.V. Sreenivasan, L. Shi, R. Huang, K. Roy, Swelling behavior of nanoscale shape- and size-specific hydrogel particles fabricated using imprint lithography. Soft Matter 7, 2879-2887 (2011). DOI: 10.1039/C0SM01185A.
M.K. Kang and R. Huang, Effect of surface tension on swell-induced surface instability of substrate-confined hydrogel layers. Soft Matter 6, 5736-5742 (2010). DOI: 10.1039/c0sm00335b.
M.K. Kang and R. Huang, Swell induced surface instability of confined hydrogel layers on substrates. J. Mech. Phys. Solids 58, 1582-1598 (2010). DOI: 10.1016/j.jmps.2010.07.008.
M.K. Kang and R. Huang, A Variational Approach and Finite Element Implementation for Swelling of Polymeric Hydrogels under Geometric Constraints. J. Appl. Mech. 77, 061004 (2010). DOI: 10.1115/1.4001715.

Thermomechanical Reliability in Advanced Packaging and 3D Integration

Collaborators: Kenneth M. Liechti (UT-AEEM) and Paul S. Ho (UT-ME)
Funding: Semiconductor Research Cooperation (SRC) and Tokyo Electron

Presentation slides:

Thermomechanical Characterization and Modeling for TSV Structures, 12th International Workshop on Stress-Induced Phenomena in Microelectronics, Kyoto, Japan. May 29, 2012.
Thermomechanical Reliability Challenges for 3D Interconnects with Through-Silicon Vias, 11th International Workshop on Stress-Induced Phenomena in Metallization, Dresden, Germany, April 14, 2010.

Publications:

S. Hao, W. Chu, P. S. Ho, J. S. Lee, R. Huang, Analytical and finite element study on warpage and stress of 2.5D chip-package structures. Proc. 2021 IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA). DOI: 10.1109/IPFA53173.2021.9617246
C. Wu, R. Huang, K.M. Liechti, Characterizing Interfacial Sliding of Through-Silicon-Via by Nano-indentation. IEEE Transcations on Device and Materials Reliability 17, 355-363 (2017). DOI: 10.1109/TDMR.2017.2681580.
T. Jiang, L. Spinella, J.-H. Im, R. Huang, P.S. Ho, Processing Effect on Via Extrusion for TSVs in Three-Dimensional Interconnects: A Comparative Study. IEEE Transcations on Device and Materials Reliability 16, 465-469 (2016).
C. Wu, S. Gowrishankar, R. Huang, K.M. Liechti, On determining mixed-mode traction-separation relations for interfaces. Int. J. Fracture 202, 1-19 (2016). DOI: 10.1007/s10704-016-0128-4.
T. Jiang, C. Wu, J. Im, R. Huang, P.S. Ho, Impact of grain structure and material properties on via extrusion in 3D interconnects. J. Microelectronics and Electronic Packaging 12, 118-122 (2015). DOI: 10.4071/imaps.456.
T. Jiang, J. Im, R. Huang, P.S. Ho, Through-silicon via stress characteristics and reliability impact on 3D Integrated Circuits. MRS Bulletin 40, 248-256 (2015).
T. Jiang, C. Wu, N. Tamura, M. Kunz, B. Kim, H.-Y. Son, M. Suh, J. Im, R. Huang, P.S. Ho, Study of stresses and plasticity in through-silicon via structures for 3D interconnects by x-ray micro-beam diffraction. IEEE Trans. on Device and Materials Reliability 14, 698-703 (2014). DOI: 10.1109/TDMR.2014.2310705.
S.-K. Ryu, T. Jiang, J. Im, P.S. Ho, R. Huang, Thermo-mechanical failure analysis of through-silicon via interface using a shear-lag model with cohesive zone. IEEE Trans. on Device and Materials Reliability 14, 318-326 (2014). DOI: 10.1109/TDMR.2013.2261300.
S.-K. Ryu, J. Im, P.S. Ho, R. Huang, A kinetic decomposition process for air-gap interconnects and induced deformation instability of a low-k dielectric cap layer. J. Mechanical Science and Technology 28, 255-261 (2014).
T. Jiang, C. Wu, L. Spinella, J. Im, N. Tamura, M. Kunz, H.-Y. Son, B.G. Kim, R. Huang, P.S. Ho, Plasticity mechanism for copper extrusion in through-silicon vias for three-dimensional interconnects. Appl. Phys. Lett. 103, 211906 (2013).
T. Jiang, S.-K. Ryu, Q. Zhao, J. Im, R. Huang and P.S. Ho, Measurement and Analysis of Thermal Stresses in 3D Integrated Structures Containing Through-Silicon Vias. Microelectronics Reliability 53, 53-62 (2013). DOI: 10.1016/j.microrel.2012.05.008. “Highly Cited Research in Microelectronics Reliability”.
S.-K. Ryu, K.-H. Lu, T. Jiang, J. Im, R. Huang, P.S. Ho, Effect of Thermal Stresses on Carrier Mobility and Keep-out Zone around Through-Silicon Vias for 3-D Integration. IEEE Trans. on Device and Materials Reliability 12, 255-262 (2012). DOI: 10.1109/TDMR.2012.2194784. Front cover.
S.-K. Ryu, Q. Zhao, M. Hecker, H. Y. Son, K. Y. Byun, J. Im, P.S. Ho, and R. Huang, Micro-Raman Spectroscopy and Analysis of Near-Surface Stresses in Silicon around Through-Silicon Vias for Three-Dimensional Interconnects. J. Appl. Phys. 111, 063513 (2012).
S.-K. Ryu, T. Jiang, K.H. Lu, J. Im, H.-Y. Son, K.-Y. Byun, R. Huang, and P.S. Ho, Characterization of thermal stresses in through-silicon vias for three-dimensional interconnects by bending beam technique. Applied Physics Letters 100, 041901 (2012).
K.H. Lu, S.-K. Ryu, Q. Zhao, K. Hummler, J. Im, R. Huang, P. S. Ho, Temperature-dependent Thermal Stress Determination for Through-Silicon-Vias (TSVs) by Combining Bending Beam Technique with Finite Element Analysis. Proc. IEEE Electronic Components and Technology Conference (ECTC), 1475-1480 (Lake Buena Vista, FL, 2011). DOI: 10.1109/ECTC.2011.5898705.
J. Mitra, M. Jung, S.-K. Ryu, R. Huang, S.-K. Lim, D. Z. Pan, A fast simulation framework for full-chip thermo-mechanical stress and reliability analysis of through-silicon-via based 3D ICs. Proc. IEEE Electronic Components and Technology Conference (ECTC), 746-753 (Lake Buena Vista, FL, 2011). DOI: 10.1109/ECTC.2011.5898596.
K.-H. Lu, S.-K. Ryu, J. Im, R. Huang, P. S. Ho, Thermomechanical reliability of through-silicon vias in 3D interconnects. Proc. 2011 IEEE International Reliability Physics Symposium (IRPS), 3D.1 (Monterey CA, 2011). DOI: 10.1109/IRPS.2011.5784487.
S.-K. Ryu, K.-H. Lu, J. Im, R. Huang, P. S. Ho, Stress-Induced Delamination Of Through Silicon Via Structures. In: International Workshop on Stress Management for 3D ICs Using Through Silicon Vias. AIP Conf. Proc. 1378, 153-167 (2011). DOI: 10.1063/1.3615702.
S.-K. Ryu, K.-H. Lu, X. Zhang, J. Im, P.S. Ho, and R. Huang, Impact of Near-Surface Thermal Stresses on Interfacial Reliability of Through-Silicon-Vias for 3-D Interconnects. IEEE Trans. on Device and Materials Reliability 11, 35-43 (2011). DOI: 10.1109/TDMR.2010.2068572.
H. Mei, S. Gowrishankar, K. M. Liechti, R. Huang, Initiation and propagation of interfacial delamination in integrated thin-film structures. Proc. 12th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm), Las Vegas, NV, June 2010. DOI: 10.1109/ITHERM.2010.5501290.
K.H. Lu, S.-K. Ryu, Q. Zhao, X. Zhang, J. Im, R. Huang, P. S. Ho, Thermal stress induced delamination of through silicon vias in 3-D interconnects. Proc. IEEE Electronic Components and Technology Conference (ECTC), 40-45 (Las Vegas, NV, 2010). DOI: 10.1109/ECTC.2010.5490883.
S.-K. Ryu, K.-H. Lu, X. Zhang, J. Im, P. S. Ho, R. Huang, Thermomechanical Reliability Challenges For 3D Interconnects With Through-Silicon Vias. In: 11th International Workshop on Stress-Induced Phenomena in Metallization. AIP Conf. Proc. 1300, 189-201 (2010). doi: 10.1063/1.3527126.
K.H. Lu, X. Zhang, S.-K. Ryu, J. Im, R. Huang, P. S. Ho, Thermo-mechanical reliability of 3-D ICs containing through silicon vias. Proc. IEEE Electronic Components and Technology Conference (ECTC), 630-634 (San Diego, CA, 2009). DOI: 10.1109/ECTC.2009.5074079.
K.H. Lu, X. Zhang, S.-K. Ryu, R. Huang, P. S. Ho, Thermal Stresses Analysis of 3-D Interconnect. In: 10th International Workshop on Stress-Induced Phenomena in Metallization. AIP Conf. Proc. 1143, 224-230 (2009). doi: 10.1063/1.3169263.
X. Zhang, R. S. Smith, R. Huang, P. S. Ho, Chip-Package Interaction and Crackstop Study for Cu/Ultra low-k Interconnects. In: 10th International Workshop on Stress-Induced Phenomena in Metallization. AIP Conf. Proc. 1143, 197-203 (2009). doi: 10.1063/1.3169259.
X. Zhang, S.-K. Ryu, R. Huang, P.S. Ho, J. Liu, D. Toma, Mechanical stability of air-gap interconnects. Future Fab 27, 81-87 (October 2008).
X. Zhang, S.-K. Ryu, R. Huang, P. S. Ho, J. Liu, D. Toma, Impact of process induced stresses and chip-packaging interaction on reliability of air-gap interconnects. Proc. 2008 IEEE International Interconnect Technology Conference (IITC), 135-137 (Burlingame, CA, 2008). DOI: 10.1109/IITC.2008.4546947.
X. Zhang, S. H. Im, R. Huang, P. S. Ho, Chip-Packaging Interaction and Reliability Impact on Cu/Low-k Interconnects. Chapter 2, Integrated Interconnect Technologies for 3D Nanoelectronic Systems (Editors: M. Bakir and J. Meindl), Artech House, Norwood, MA, 2008.
H. Mei, Y. Pang, S. H. Im, R. Huang, Fracture, delamination, and buckling of elastic thin films on compliant substrates. Proc. 11th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm), pp. 762-769, Orlando, FL, May 2008. DOI: 10.1109/ITHERM.2008.4544345.

Mechanics of Graphene and 2D Materials

Collaborators: Kenneth M. Liechti (UT-Austin), Nanshu Lu (UT-Austin), Li Shi (UT Austin), R.S. Ruoff
Funding: National Science Foundation

Presentation slides:

Mechanical Interactions at the Interfaces of Atomically Thin Materials (Graphene), at the 2018 MRS Spring Meeting, Phoenix, AZ, April 4, 2018.
Thermomechanical and Interfacial Properties of Graphene, Department of Mechanical Engineering, Stanford University. February 20, 2014.
Continuum Mechanics and Atomistic Modeling of Graphene, Department of Mechanical Engineering, Columbia University, New York, NY. November 5, 2010.

Publications:

J. Quan, G. Chen, L. Linhart, Z. Liu, T. Taniguchi, K. Watanabe, F. Libisch, R. Huang, X. Li, Quantifying Strain in Moiré Superlattic e. Nano Letters 23, 11510-11516 (2023). DOI
P. Sokalski, Z. Han, G. C. Fleming, B. Smith, S. E. Sullivan, R. Huang, X. Ruan, L. Shi, Effects of hot phonons and thermal stress in micro-Raman spectra of molybdenum disulphide. Appl. Phys. Lett. 121, 182202 (2022). DOI. arXiv:2206.15473.
V. Morovati, Z. Xue, K. M. Liechti, R. Huang, Interlayer Coupling and Strain Localization in Small-Twist-Angle Graphene Flakes.
Extreme Mechanics Letters 55, 101829 (2022). DOI. Preprint: arXiv:2206.02613
Z. Xue, G. Chen, C. Wang, R. Huang, Peeling and sliding of graphene nanoribbons with periodic van der Waals interactions.
J. Mech. Phys. Solids 158, 104698 (2022). DOI
Z. Dai, N. Lu, K.M. Liechti, R. Huang, Mechanics at the Interfaces of 2D Materials: Challenges and Opportunities. Current Opinion in Solid State and Materials Science 24, 100837 (2020). DOI
R. Huang, Bending with slip. Nature Materials 19, 259-260 (2020).
C. Xu, T. Yang, Y. Kang, Q. Li, T. Xue, K.M. Liechti, R. Huang, W. Qiu, Rate-dependent decohesion modes in graphene sandwiched interfaces. Advanced Materials Interfaces, 1901217 (2019). DOI
G. Wang, Z. Dai, J. Xiao, S. Feng, C. Weng, L. Liu, Z. Xu, R. Huang, Z. Zhang, Bending of multilayer van der Waals materials. Phys. Rev. Lett. 123, 116101 (2019). DOI: 10.1103/PhysRevLett.123.116101 . MRS News.
B. Smith, L. Lindsay, J. Kim, E. Ou, R. Huang, L. Shi, Phonon Interaction with Ripples and Defects in Thin Layered Molybdenum Disulfide. Appl. Phys. Lett. 114, 221902 (2019). DOI: 10.1063/1.5099103.
D. A. Sanchez, Z. Dai, P. Wang, A. Cantu-Chaveza, C. J. Brennan, R. Huang, N. Lu, Mechanics of Spontaneously Formed Nanoblisters Trapped by Transferred 2D Crystals. PNAS, 115, 7884-7889 (2018). DOI: 10.1073/pnas.1801551115.
G. Wang, Z. Dai, Y. Wang, P. Tan, L. Liu, Z. Xu, Y. Wei, R. Huang, Z. Zhang, Measuring Interlayer Shear Stress in Bilayer Graphene. Phys. Rev. Lett. 119, 036101 (2017). DOI: 10.1103/PhysRevLett.119.036101. Featured in Physics Focus: Graphene Sliding on Graphene. Editors’ Suggestion: Highlights.
F. Ahmadpoor, P. Wang, R. Huang, P. Sharma, Thermal Fluctuations and Effective Bending Stiffness of Elastic Thin Sheets and Graphene: A Nonlinear Analysis. J. Mech. Phys. Solids 107, 294-319 (2017). DOI: 10.1016/j.jmps.2017.07.11.
D. Akinwande, C.J. Brennan, J.S. Bunch, P. Egberts, J.R. Felts, H. Gao, R. Huang, J.-S. Kim, T. Li, Y. Li, K.M. Liechti, N. Lu, H.S. Park, E.J. Reed, P. Wang, B.I. Yakobson, T. Zhang, Y.-W. Zhang, Y. Zhou, Y. Zhu, A Review on Mechanics and Mechanical Properties of 2D Materials – Graphene and Beyond. Extreme Mechanics Letters 13, 42-72 (2017). DOI: 10.1016/j.eml.2017.01.008. Preprint at arXiv:1611.01555.
S.R. Na, X. Wang, R.D. Piner, R. Huang, C.G. Willson, K. M. Liechti, Cracking of Polycrystalline Graphene on Copper Under Tension. ACS Nano 10, 9616-9625 (2016). DOI: 10.1021/acsnano.6b05101.
P. Wang, K.M. Liechti, R. Huang, Snap transitions of pressurized graphene blisters. Journal of Applied Mechanics 83, 071002 (2016). DOI: 10.1115/1.4033305.
P. Wang, W. Gao, R. Huang, Entropic effects of thermal rippling on van der Waals interactions between monolayer graphene and a rigid substrate. J. Applied Physics 119, 074305 (2016). Preprint at arXiv:1511.02914.
Z. Cao, L. Tao, D. Akinwande, R. Huang, K.M. Liechti, Mixed-mode traction-separation relations between graphene and copper by blister tests. Int. J. Solids and Structures 84, 147-159 (2016). DOI: 10.1016/j.ijsolstr.2016.01.023.
Z. Cao, L. Tao, D. Akinwande, R. Huang, K.M. Liechti, Mixed-mode interactions between graphene and substrates by blister tests. Journal of Applied Mechanics 82, 081008 (2015). DOI: 10.1115/1.4030591.
W. Gao, K.M. Liechti, R. Huang, Wet adhesion of graphene. Extreme Mechanics Letters 3, 130-140 (2015). DOI: 10.1016/j.eml.2015.04.003.
S.R. Na, J.W. Suk, L. Tao, D. Akinwande, R.S. Ruoff, R. Huang, K. M. Liechti, Selective Mechanical Transfer of Graphene from Seed Copper Foil Using Rate Effects. ACS Nano 9, 1325-1335 (2015). DOI: 10.1021/nn505178g.
S.R. Na, J.W. Suk, R.S. Ruoff, R. Huang, K. M. Liechti, Ultra Long-Range Interactions between Large Area Graphene and Silicon. ACS Nano 8, 11234-11242 (2014). DOI: 10.1021/nn503624f.
W. Gao, P. Xiao, G. Henkelman, K.M. Liechti, R. Huang, Interfacial adhesion between graphene and silicon dioxide by density functional theory with van der Waals corrections. J. Phys. D: Appl. Phys. 47, 255301 (2014). arXiv:1403.3751.
W. Gao and R. Huang, Thermomechanics of monolayer graphene: Rippling, thermal expansion and elasticity. Journal of the Mechanics and Physics of Solids 66, 42-58 (2014). DOI: 10.1016/j.jmps.2014.01.011.
Z. Cao, P. Wang, W. Gao, L. Tao, J.W. Suk, R.S. Ruoff, D. Akinwande, R. Huang, K.M. Liechti, A blister test for interfacial adhesion of large-scale transferred graphene. Carbon 69, 390-400 (2014) . DOI: 10.1016/j.carbon.2013.12.041.
T. Jiang, R. Huang, Y. Zhu, Interfacial Sliding and Buckling of Monolayer Graphene on a Stretchable Substrate. Advanced Functional Materials 24, 396-402 (2014). Supporting Information. DOI: 10.1002/adfm.201301999.
P. Wang, W. Gao, Z. Cao, K.M. Liechti, R. Huang, Numerical analysis of circular graphene bubbles. J. Applied Mechanics 80, 040905 (2013). doi:10.1115/1.4024169.
K. Yue, W. Gao, R. Huang, K.M. Liechti, Analytical methods for the mechanics of graphene bubbles. J. Appl. Phys. 112, 083512 (2012).
W. Gao and R. Huang, Effect of surface roughness on adhesion of graphene membranes. J. Phys. D: Appl. Phys. 44, 452001 (2011).
R. Huang, Graphene: Show of adhesive strength (news and views). Nature Nanotechnology 6, 537-538 (2011).
Q. Lu and R. Huang, Mechanical Behavior of Monolayer Graphene by Continuum and Atomistic Modeling. Chapter 14 in: Simulations in Nanobiotechnology (Editor: K. Eom), CRC Press, 2011.
Q. Lu, W. Gao and R. Huang, Atomistic simulation and continuum modeling of graphene nanoribbons under uniaxial tension. Modelling and Simulation in Materials Science and Engineering 19, 054006 (2011). Posted online at arXiv:1007.3298.
Q. Lu and R. Huang, Nonlinear Mechanical Properties of Graphene Nanoribbons, MRS Proceedings, vol. 1284, mrsf10-1284-c14-02 (2011). DOI: 10.1557/opl.2011.226.
Z.H. Aitken and R. Huang, Effects of mismatch strain and substrate surface corrugation on morphology of supported monolayer graphene. J. Appl. Phys. 107, 123531 (2010). Posted online at arXiv:1003.0853.
J.H. Seol, I. Jo, A.L. Moore, L. Lindsay, Z.H. Aitken, M.T. Pettes, X. Li, Z. Yao, R. Huang, D. Broido, N. Mingo, R.S. Ruoff, and L. Shi, Two-dimensional phonon transport in supported graphene. Science 328, 213-216 (2010). DOI: 10.1126/science.1184014.
Q. Lu and R. Huang, Excess energy and deformation along free edges of graphene nanoribbons. Physical Review B 81, 155410 (2010). Preprint posted online at arXiv:0910.0912, October 2009.
Q. Lu and R. Huang, Nonlinear mechanics of single-atomic-layer graphene sheets. Int. J. Applied Mechanics 1, 443-467 (2009).
Q. Lu, M. Arroyo, R. Huang, Elastic bending modulus of monolayer graphene. J. Phys. D: Appl. Phys. 42, 102002 (2009). Posted online at arXiv:0901.4370v1.
J. Zhou and R. Huang, Internal lattice relaxation of single-layer graphene under in-plane deformation. Journal of the Mechanics and Physics of Solids 56, 1609-1623 (2008).

Buckling of Nanostructures

Collaborators: Paul S. Ho (UT-Austin)
Funding: National Science Foundation

Publications:

B. Li, Q. Zhao, H. Huang, Z. Luo, M.K. Kang, J.-H. Im, R. Allen, M.W. Cresswel, R. Huang, and P.S Ho, Indentation of Single-Crystal Silicon Nanolines: Buckling and Contact Friction at Nanoscales. J. Applied Physics 105, 073510 (2009).
H. Huang, B. Li, Q. Zhao, Z. Luo, J. Im, M. K. Kang, R. A. Allen, M. W. Cresswell, R. Huang, P. S. Ho, Nanoindentation of Si Nanostructures: Buckling and Friction at Nanoscales. In: 10th International Workshop on Stress-Induced Phenomena in Metallization. AIP Conf. Proc. 1143, 204-212 (2009). doi: 10.1063/1.3169260.
B. Li, H. Huang, Q. Zhao, Z. Luo, J.-H. Im, P.S Ho, M.K. Kang, R. Huang, and M.W. Cresswel, Mechanical Characterization of High Aspect Ratio Silicon Nanolines. In: Mechanics of Nanoscale Materials, edited by C. Friesen, R.C. Cammarata, A. Hodge, O.L. Warren (Mater. Res. Soc. Symp. Proc., vol. 1086E, Warrendale, PA, 2008), 1086-U05-07.
M. K. Kang, B. Li, P.S. Ho, R. Huang, Buckling of Single-Crystal Silicon Nanolines under Indentation. Journal of Nanomaterials, Vol. 2008, Article ID 132728 (11 pages), April 2008. DOI: 10.1155/2008/132728.
B. Li, M. K. Kang, K. Lu, R. Huang, P. S. Ho, R. A. Allen, and M. W. Cresswell, Fabrication and Characterization of Patterned Single-Crystal Silicon Nanolines. Nano Letters 8, 92 -98 (2008).

Wrinkling of Thin Films on Soft Substrates

Collaborators: C.M. Stafford (NIST), Z. Suo (Harvard Univ.)
Funding: National Science Foundation and DARPA

Presentation slides:

Nonlinear Dynamics of Wrinkle Growth and Pattern Formation in Stressed Elastic Thin Films, APS March Meeting, Pittsburgh, March 18, 2009.

Publications:

S. Mane and R. Huang, Rate-dependent wrinkling and subsequent bifurcations of an elastic thin film on a viscoelastic layer. International Journal of Solids and Structures 257, 111592 (2022). DOI
C.M. Landis, R. Huang, J.W. Hutchinson, Formation of surface wrinkles and creases in constrained dielectric elastomers subject to electromechanical loading. J. Mech. Phys. Solids 167, 105023 (2022). DOI
S. Chatterjee, C. McDonald, J. Niu, S. Velankar, P. Wang, R. Huang, Wrinkling and folding of thin films by viscous stress. Soft Matter 11, 1814-1827 (2015). DOI: 10.1039/C4SM02501F.
K. Pan, Y. Ni, L. He, R. Huang, Nonlinear analysis of compressed elastic thin films on elastic substrates: from wrinkling to buckle-delamination. International Journal of Solids and Structures 51, 3715-3726 (2014). DOI: 10.1016/j.ijsolstr.2014.07.005.
J.-H. Lee, H.W. Ro, R. Huang, P. Lemaillet, T.A. Germer, C.L. Soles, C.M. Stafford, Anisotropic, Hierarchical Surface Patterns via Surface Wrinkling of Nanoimprinted Polymer Films. Nano Letters 12, 5995-5999 (2012). DOI: 10.1021/nl303512d.
C. Guo, V. Nayyar, Z. Zhang, Y. Chen, J. Miao, R. Huang and Q. Liu, Path-guided wrinkling of nanoscale metal films. Advanced Materials 24, 3010-3014 (2012). DOI: 10.1002/adma.201200540. Supporting Information and Back Cover.
J. Li, Y. An, R. Huang, H. Jiang, T. Xie, Unique aspects of a shape memory polymer as the substrate for surface wrinkling. ACS Applied Materials and Interfaces 4, 598-603 (2012). DOI: 10.1021/am201727a
H. Mei, C.M. Landis, R. Huang, Concomitant wrinkling and buckle-delamination of elastic thin films on compliant substrates. Mechanics of Materials 43, 627-642 (2011). DOI: 10.1016/j.mechmat.2011.08.003.
E.P. Chan, K.A. Page, S.H. Im, D.L. Patton, R. Huang, C.M. Stafford, Viscoelastic properties of confined polymer films measured via thermal wrinkling. Soft Matter 5, 4638-4641 (2009).
S. H. Im and R. Huang, Wrinkle Patterns of Anisotropic Crystal Films on Viscoelastic Substrates. J. Mech. Phys. Solids 56, 3315-3330 (2008). doi: 10.1016/j.jmps.2008.09.011.
H. Mei, J.Y. Chung, H.-H. Yu, C.M. Stafford, and R. Huang, Buckling modes of elastic thin films on elastic substrates. Applied Physics Letters 90, 151902 (2007).
R. Huang, C.M. Stafford, B.D. Vogt, Effect of surface properties on wrinkling of ultrathin films. J. Aerospace Engineering 20, 38-44 (2007).
R. Huang, C.M. Stafford, B.D. Vogt, Wrinkling of ultrathin polymer films. In: Mechanics of Nanoscale Materials and Devices, edited by A. Misra, J.P. Sullivan, H. Huang, K. Lu, and S. Asif (Mater. Res. Soc. Symp. Proc., vol. 924E, Warrendale, PA, 2006), 0924-Z04-10.
R. Huang and S.H. Im, Dynamics of wrinkle growth and coarsening in stressed thin films. Physical Review E 74, 026214 (2006).
C.M. Stafford, B.D. Vogt, C. Harrison, D. Julthongpiput, R. Huang, Elastic Moduli of Ultrathin Amorphous Polymer Films. Macromolecules 39, 5095-5099 (2006).
R. Huang, Electrically induced surface instability of a conductive thin film on a dielectric substrate. Applied Physics Letters 87, 151911 (2005).
S.H. Im and R. Huang, Evolution of wrinkles in elastic-viscoelastic bilayer thin films. J. Applied Mechanics 72, 955-961 (2005).
R. Huang, Kinetic wrinkling of an elastic film on a viscoelastic substrate. Journal of the Mechanics and Physics of Solids 53, 63-89 (2005).
S.H. Im and R. Huang, Morphological instability and kinetics of an elastic film on a viscoelastic layer. Proceedings of IUTAM Symposium on Size Effects on Material and Structure Behavior at Micron- and Nano-Scales (Eds. Q.P. Sun and P. Tong, Hong Kong, 31 May – 4 June, 2004), Springer 2006, pp. 41-50.
S.H. Im and R. Huang, Ratcheting-induced wrinkling of an elastic film on a metal layer under cyclic temperatures. Acta Mater 52, 3707-3719 (2004).
R. Huang and Z. Suo, Very thin solid-on-liquid structures: the interplay of flexural rigidity, membrane force, and interfacial force. Thin Solid Films 429, 273-281 (2003).
R. Huang and Z. Suo, Morphological instability of solid-on-liquid thin film structures. MRS Symposium Proceedings, vol. 749, 121-126 (2002).
R. Huang and Z. Suo, Instability of a compressed elastic film on a viscous layer. International Journal of Solids and Structures 39, 1791-1802 (2002).
R. Huang and Z. Suo, Wrinkling of a compressed elastic film on a viscous layer. Journal of Applied Physics 91, 1135-1142 (2002).

Surface Morphological Evolution and Self-Assembly of Quantum Dots

Collaborators: Sanjay Banerjee (UT Austin)
Funding: Department of Energy

Publications:

Y. Pang and R. Huang, Effect of Elastic Anisotropy on Surface Pattern Evolution of Epitaxial Thin Films. Int. J. Solids and Structures 46, 2822-2833 (2009).
Y. Pang and R. Huang, Bifurcation of Surface Pattern in Epitaxial Thin Films under Anisotropic Stresses. J. Applied Physics 101, 023519 (2007).
Y. Pang and R. Huang, Pattern Evolution of Self-Assembled Quantum Dots Under Biaxial Stresses. In: Nanomanufacturing, edited by F. Stellacci, J.W. Perry, G.S. Herman, and R.N. Das (Mater. Res. Soc. Symp. Proc., vol. 921E, Warrendale, PA, 2006), 0921-T07-08.
Y. Pang and R. Huang, Nonlinear effect of stress and wetting on surface evolution in epitaxial thin films. Physical Review B 74, 075413 (2006).
H. Liu and R. Huang, Effect of a cap layer on morphological stability of a strained epitaxial film. J. Applied Physics 97, 113537 (2005).

Stress Relaxation and Interface Diffusion in Copper Interconnects

Collaborators: Paul S. Ho (UT Austin) and Jun He (Intel)
Funding: Advanced Technology Program of Texas Higher Education Coordinating Board and Intel Corporation

Publications:

H. Mei, J.H. An, R. Huang, and P.J. Ferreira, Finite element modeling of stress variation in multilayer thin-film specimens for in-situ transmission electron microscopy experiments. Journal of Materials Research 22, 2737-2741 (2007).
D.W. Gan, P.S. Ho, Y. Pang, R. Huang, J. Leu, J. Maiz, T. Scherban, Effect of passivation on stress relaxation in electroplated copper films. J. Materials Research 21, 1512-1518 (2006).
D.W. Gan, R. Huang, P.S. Ho, J. Leu, J. Maiz, T. Scherban, Effects of passivation layer on stress relaxation and mass transport in electroplated Cu films. Proceedings of the 7th International Workshop on Stress-Induced Phenomena in Metallization, Austin, Texas, 14-16 June 2004. AIP Conference Proceedings 741, 256-267 (2004).
R. Huang, D.W. Gan, P.S. Ho, Isothermal stress relaxation in electroplated Cu films. Part II: Kinetic modeling. J. Applied Physics 97, 103532 (2005).
D.W. Gan, R. Huang, P.S. Ho, J. Leu, J. Maiz, T. Scherban, Isothermal stress relaxation in electroplated Cu films. Part I: Mass transport measurements. J. Applied Physics 97, 103531 (2005).

Fracture in Thin-Film Structures

Collaborators: Z. Suo (Harvard Univ.), J.H. Prevost (Princeton Univ.)
Funding: National Science Foundation

Presentation slides:

Fracture of Brittle Thin Films on Compliant Substrates, 12th International Conference on Fracture, Ottawa, Canada, July 16, 2009.

Publications:

C. Wu, S. Gowrishankar, R. Huang, K.M. Liechti, On determining mixed-mode traction-separation relations for interfaces. Int. J. Fracture 202, 1-19 (2016). DOI: 10.1007/s10704-016-0128-4.
S. Gowrishankar, H. Mei, K.M. Liechti and R. Huang, A comparison of direct and iterative methods for determining traction-separation relations. International Journal of Fracture 177, 109-128 (2012). DOI: 10.1007/s10704-012-9758-3.
H. Mei, Y. Pang, and R. Huang, Influence of interfacial delamination on channel cracking of elastic thin films. International Journal of Fracture 148, 331-342 (2007).
Y. Pang and R. Huang, Influence of interfacial delamination on channel cracking of brittle thin films. In: Materials, Processes, Integration and Reliability in Advanced Interconnects for Micro- and Nanoelectronics, edited by Q. Lin, E.T. Ryan, W-L. Wu, D.Y. Yoon (Mater. Res. Soc. Symp. Proc. Vol. 990, Warrendale, PA), B06-04, 2007.
J. Liang, R. Huang, J.H. Prevost, and Z. Suo, Thin film cracking modulated by underlayer creep. Experimental Mechanics, 43, 269-279 (2003).
R. Huang, N. Sukumar, J.H. Prevost, Modeling quasi-static crack growth with the extended finite element method -Part II: Numerical Applications. International Journal of Solids and Structures 40, 7539-7552 (2003).
R. Huang, J.H. Prevost, Z.Y. Huang, and Z. Suo, Channel-cracking of thin films with the extended finite element method. Engineering Fracture Mechanics 70, 2513-2526 (2003).
J. Liang, R. Huang, J.H. Prevost, and Z. Suo, Evolving crack patterns in thin films with the extended finite element method. International Journal of Solids and Structures 40, 2343-2354 (2003).
R. Huang, J.H. Prevost, and Z. Suo, Loss of constraint on fracture in thin film structures due to creep. Acta Materialia 50, 4137-4148 (2002).

Strain-Relaxed SiGe Islands on Oxides

Collaborators: Z. Suo, J.C. Sturm, K.D. Hobart, H. Yin
Funding: National Science Foundation and DARPA

Publications:

H. Yin, R. Huang, K.D. Hobart, J. Liang, Z. Suo, S.R. Shieh, T.S. Duffy, F.J. Kub, J.C. Sturm, Buckling suppression of SiGe islands on compliant substrates. Journal of Applied Physics 94, 6875-6882 (2003).
R. Huang and Z. Suo, Very thin solid-on-liquid structures: the interplay of flexural rigidity, membrane force, and interfacial force. Thin Solid Films 429, 273-281 (2003).
R. Huang, Z. Suo, Morphological instability of solid-on-liquid thin film structures. MRS Symposium Proceedings, vol. 749, 121-126 (2002).
R. Huang, H. Yin, J. Liang, J.C. Sturm, K.D. Hobart, Z. Suo, Mechanics of relaxing SiGe islands on a viscous glass. Acta Mechanica Sinica 18, 441-456 (2002).
H. Yin, R. Huang, K.D. Hobart, Z. Suo, T.S. Kuan, C.K. Inoki, S.R. Shieh, T.S. Duffy, F.J. Kub, J.C. Sturm, Strain relaxation of SiGe islands on compliant oxide. Journal of Applied Physics 91, 9716-9722 (2002).
J. Liang, R. Huang, H. Yin, J. C. Sturm, K. D. Hobart, and Z. Suo, Relaxation of compressed elastic islands on a viscous layer. Acta Materialia 50, 2933-2944 (2002).
R. Huang and Z. Suo, Instability of a compressed elastic film on a viscous layer. International Journal of Solids and Structures 39, 1791-1802 (2002).
R. Huang and Z. Suo, Wrinkling of a compressed elastic film on a viscous layer. Journal of Applied Physics 91, 1135-1142 (2002).
R. Huang, H. Yin, J. Liang, K. D. Hobart, J. C. Sturm, and Z. Suo, Relaxation of a strained elastic film on a viscous layer. MRS Symposium Proceedings, vol. 695, 115-120 (2001).

Deformation Mechanisms in Metallic Glasses

Collaborators: Z. Suo, J.H. Prevost, W.D. Nix
Funding: National Science Foundation

Publications:

R. Huang, Z. Suo, J.H. Prevost, and W.D. Nix, Inhomogeneous deformation in metallic glasses. Journal of the Mechanics and Physics of Solids 50, 1011-1027 (2002).

Theory and Applications of Mechanical Resonators

“Vibrations of Piezoelectric Crystal Plates with Thickness-Graded Material Properties”, PhD thesis, Princeton University, January 2001.
Advisor: Peter C. Y. Lee
Collaborators: Jiun-Der Yu, Wen-Sen Lin, W.H. Shih, T. Knowles
Funding: U.S. Army Research Office

Publications:

M. K. Kang, R. Huang, T. Knowles, Energy-Trapping Torsional-Mode Resonators for Liquid Sensing. Proc. 2006 IEEE International Frequency Control Symposium and Exposition, pp. 133-138, Miami, FL, June 2006. DOI: 10.1109/FREQ.2006.275365.
M. K. Kang, R. Huang, T. Knowles, Trapped Torsional Vibrations in Elastic Plates. Proc. 2006 IEEE International Frequency Control Symposium and Exposition, pp. 40-47, Miami, FL, June 2006. DOI: 10.1109/FREQ.2006.275349.
T. Knowles, M.K. Kang, R. Huang, Trapped torsional vibrations in elastic plates. Applied Physics Letters 87, 201911 (2005).
M.K. Kang, R. Huang, T. Knowles, Torsional vibrations of circular elastic plates with thickness steps. IEEE Trans. Ultrasonics, Ferroelectrics and Frequency Control, vol. 53, 349-359 (2006).
R. Huang, P.C.Y. Lee, W.S. Lin and J.D. Yu, Extensional, thickness-stretch, and symmetric thickness-shear vibrations of piezoelectric ceramic disks. IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 49, 1507-1515 (2002).
P.C. Y. Lee and R. Huang, Mechanical effects of electrodes on the vibrations of quartz crystal plates. IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 49, 612-625 (2002).
P.C.Y. Lee and R. Huang, Effects of a liquid layer on thickness-shear vibrations of rectangular AT-cut quartz plates. IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 49, 604-611 (2002).
P.C.Y. Lee, R. Huang, X. Li, and W. H. Shih, Vibrations and static responses of asymmetric bimorph disks of piezoelectric ceramics. IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 47, 706-715 (2000).