Christian Linder
Professor of Civil and Environmental Engineering and, by courtesy, of Mechanical Engineering
Bio
Christian Linder is a Professor of Civil and Environmental Engineering and, by courtesy, of Mechanical Engineering. Through the development of novel and efficient in-house computational methods based on a sound mathematical foundation, the research goal of the Computational Mechanics of Materials (CM2) Lab at Stanford University, led by Dr. Linder, is to understand micromechanically originated multi-scale and multi-physics mechanisms in solid materials undergoing large deformations and fracture. Applications include sustainable energy storage materials, flexible electronics, and granular materials.
Dr. Linder received his Ph.D. in Civil and Environmental Engineering from UC Berkeley, an MA in Mathematics from UC Berkeley, an M.Sc. in Computational Mechanics from the University of Stuttgart, and a Dipl.-Ing. degree in Civil Engineering from TU Graz. Before joining Stanford in 2013 he was a Junior-Professor of Micromechanics of Materials at the Applied Mechanics Institute of Stuttgart University where he also obtained his Habilitation in Mechanics. Notable honors include a Fulbright scholarship, the 2013 Richard-von-Mises Prize, the 2016 ICCM International Computational Method Young Investigator Award, the 2016 NSF CAREER Award, and the 2019 Presidential Early Career Award for Scientists and Engineers (PECASE).
Academic Appointments
-
Professor, Civil and Environmental Engineering
-
Professor (By courtesy), Mechanical Engineering
-
Member, Bio-X
-
Member, Wu Tsai Neurosciences Institute
Honors & Awards
-
2019 Presidential Early Career Award for Scientists and Engineers, White House Office of Science and Technology (2019)
-
2016 NSF CAREER Award, National Science Foundation (2016)
-
2016 ICCM Young Investigator Award, International Conference on Computational Methods (2016)
-
Richard-von-Mises Prize, International Association of Applied Mathematics and Mechanics (2013)
-
Haythornthwaite Research Initiation Award, ASME Applied Mechanics Division. (2013)
Professional Education
-
Habilitation, University of Stuttgart, Mechanics (2012)
-
PhD, UC Berkeley, Computational Mechanics (2007)
-
MA, UC Berkeley, Mathematics (2006)
-
MSc, University of Stuttgart, Computational Mechanics of Materials and Structures (2003)
-
Dipl.-Ing., Graz University of Technology, Civil and Environmental Engineering (2001)
2024-25 Courses
- Mechanics of Materials
CEE 101A (Win) - Solid Mechanics
CEE 291 (Aut) -
Independent Studies (8)
- Advanced Engineering Problems
CEE 399 (Aut, Win, Spr) - Directed Reading or Special Studies in Civil Engineering
CEE 198 (Aut, Win, Spr) - Independent Project in Civil and Environmental Engineering
CEE 199L (Aut, Win, Spr) - Independent Project in Civil and Environmental Engineering
CEE 299L (Aut, Win, Spr) - Independent Study in Civil Engineering for CEE-MS Students
CEE 299 (Aut, Win, Spr) - Report on Civil Engineering Training
CEE 398 (Aut, Win, Spr) - Undergraduate Honors Thesis
CEE 199H (Aut, Win, Spr) - Undergraduate Research in Civil and Environmental Engineering
CEE 199 (Aut, Win, Spr)
- Advanced Engineering Problems
-
Prior Year Courses
2023-24 Courses
- Mechanics of Materials
CEE 101A (Win) - Solid Mechanics
CEE 291 (Aut)
2022-23 Courses
- Mechanics of Materials
CEE 101A (Win) - Solid Mechanics
CEE 291 (Aut)
2021-22 Courses
- Computational Solid Mechanics
CEE 310 (Spr) - Mechanics of Materials
CEE 101A (Win) - Solid Mechanics
CEE 291 (Aut)
- Mechanics of Materials
Stanford Advisees
-
Doctoral Dissertation Reader (AC)
Giancarlo Ventura, Enrique del Castillo -
Doctoral Dissertation Advisor (AC)
Sina Abrari Vajari, Ryan McAvoy -
Master's Program Advisor
Anna Cecil, Even Chen, Benjamin Idler, Marshall Kobylski, Zhiyang Mao, Olivia Pinto, Varun Sahay, Andrew Wang, Tingyu Wang, Zexi Yin, Shujun Zhang -
Doctoral (Program)
Sungwon La, Jinchen Xie
All Publications
-
Investigation of driving forces in a phase field approach to mixed mode fracture of concrete
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
2023; 417
View details for DOI 10.1016/j.cma.2023.116404
View details for Web of Science ID 001086624500001
-
A multiscale phase field fracture approach based on the non-affine microsphere model for rubber-like materials
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
2023; 410
View details for DOI 10.1016/j.cma.2023.115982
View details for Web of Science ID 000966263300001
-
A thermodynamically consistent finite strain phase field approach to ductile fracture considering multi-axial stress states
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
2022; 400
View details for DOI 10.1016/j.cma.2022.115467
View details for Web of Science ID 000862754300005
-
Energy based fracture initiation criterion for strain-crystallizing rubber-like materials with pre-existing cracks
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
2021; 157
View details for DOI 10.1016/j.jmps.2021.104617
View details for Web of Science ID 000702760500002
-
A non-affine micro-macro approach to strain-crystallizing rubber-like materials
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
2018; 111: 67–99
View details for DOI 10.1016/j.jmps.2017.10.007
View details for Web of Science ID 000424178500004
-
On the enhancement of low-order mixed finite element methods for the large deformation analysis of diffusion in solids
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
2016; 106 (4): 278-297
View details for DOI 10.1002/nme.5120
View details for Web of Science ID 000373348900002
-
Tri-layer wrinkling as a mechanism for anchoring center initiation in the developing cerebellum
SOFT MATTER
2016; 12 (25): 5613-5620
Abstract
During cerebellar development, anchoring centers form at the base of each fissure and remain fixed in place while the rest of the cerebellum grows outward. Cerebellar foliation has been extensively studied; yet, the mechanisms that control anchoring center initiation and position remain insufficiently understood. Here we show that a tri-layer model can predict surface wrinkling as a potential mechanism to explain anchoring center initiation and position. Motivated by the cerebellar microstructure, we model the developing cerebellum as a tri-layer system with an external molecular layer and an internal granular layer of similar stiffness and a significantly softer intermediate Purkinje cell layer. Including a weak intermediate layer proves key to predicting surface morphogenesis, even at low stiffness contrasts between the top and bottom layers. The proposed tri-layer model provides insight into the hierarchical formation of anchoring centers and establishes an essential missing link between gene expression and evolution of shape.
View details for DOI 10.1039/c6sm00526h
View details for Web of Science ID 000378935000013
View details for PubMedID 27252048
-
Computational aspects of growth-induced instabilities through eigenvalue analysis
COMPUTATIONAL MECHANICS
2015; 56 (3): 405-420
View details for DOI 10.1007/s00466-015-1178-6
View details for Web of Science ID 000359381500002
-
All-electron Kohn-Sham density functional theory on hierarchic finite element spaces
JOURNAL OF COMPUTATIONAL PHYSICS
2013; 250: 644-664
View details for DOI 10.1016/j.jcp.2013.04.020
View details for Web of Science ID 000321433800032
-
Effect of electric displacement saturation on the hysteretic behavior of ferroelectric ceramics and the initiation and propagation of cracks in piezoelectric ceramics
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
2012; 60 (5): 882-903
View details for DOI 10.1016/j.jmps.2012.01.012
View details for Web of Science ID 000302444000005
-
The maximal advance path constraint for the homogenization of materials with random network microstructure
PHILOSOPHICAL MAGAZINE
2012; 92 (22): 2779-2808
View details for DOI 10.1080/14786435.2012.675090
View details for Web of Science ID 000307448400005
-
A micromechanically motivated diffusion-based transient network model and its incorporation into finite rubber viscoelasticity
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
2011; 59 (10): 2134-2156
View details for DOI 10.1016/j.jmps.2011.05.005
View details for Web of Science ID 000295549500011
-
Finite elements with embedded strong discontinuities for the modeling of failure in solids
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
2007; 72 (12): 1391-1433
View details for DOI 10.1002/nme.2042
View details for Web of Science ID 000251949400002
-
Plane strain problem of flexoelectric cylindrical inhomogeneities
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
2024; 289
View details for DOI 10.1016/j.ijsolstr.2024.112649
View details for Web of Science ID 001154964600001
-
Analysis of Flexoelectric Solids With a Cylindrical Cavity
JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME
2024; 91 (1)
View details for DOI 10.1115/1.4063145
View details for Web of Science ID 001124227500004
-
Highly stretchable polymer semiconductor thin films with multi-modal energy dissipation and high relative stretchability.
Nature communications
2023; 14 (1): 8382
Abstract
Stretchable polymer semiconductors (PSCs) have seen great advancements alongside the development of soft electronics. But it remains a challenge to simultaneously achieve high charge carrier mobility and stretchability. Herein, we report the finding that stretchable PSC thin films (<100-nm-thick) with high stretchability tend to exhibit multi-modal energy dissipation mechanisms and have a large relative stretchability (rS) defined by the ratio of the entropic energy dissipation to the enthalpic energy dissipation under strain. They effectively recovered the original molecular ordering, as well as electrical performance, after strain was released. The highest rS value with a model polymer (P4) exhibited an average charge carrier mobility of 0.2 cm2V-1s-1 under 100% biaxial strain, while PSCs with low rS values showed irreversible morphology changes and rapid degradation of electrical performance under strain. These results suggest rS can be used as a parameter to compare the reliability and reversibility of stretchable PSC thin films.
View details for DOI 10.1038/s41467-023-44099-w
View details for PubMedID 38104194
View details for PubMedCentralID 8367968
-
An analytical model for nanoscale flexoelectric doubly curved shells
MATHEMATICS AND MECHANICS OF SOLIDS
2023
View details for DOI 10.1177/10812865231186116
View details for Web of Science ID 001038461300001
-
SenseNet: A Physics-Informed Deep Learning Model for Shape Sensing
JOURNAL OF ENGINEERING MECHANICS
2023; 149 (3)
View details for DOI 10.1061/JENMDT.EMENG-6901
View details for Web of Science ID 000914167000006
-
A better understanding of the mechanics of borehole breakout utilizing a finite strain gradient-enhanced micropolar continuum model
COMPUTERS AND GEOTECHNICS
2023; 153
View details for DOI 10.1016/j.compgeo.2022.105064
View details for Web of Science ID 000900021700003
-
A unified finite strain gradient-enhanced micropolar continuum approach for modeling quasi-brittle failure of cohesive-frictional materials
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
2022; 254
View details for DOI 10.1016/j.ijsolstr.2022.111841
View details for Web of Science ID 000830830700005
-
Understanding thermal and mechanical effects on lithium plating in lithium-ion batteries
JOURNAL OF POWER SOURCES
2022; 541
View details for DOI 10.1016/j.jpowsour.2022.231632
View details for Web of Science ID 000822974200004
-
A Modified Electrochemical Model to Account for Mechanical Effects Due to Lithium Intercalation and External Pressure
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
2021; 168 (2)
View details for DOI 10.1149/1945-7111/abe16d
View details for Web of Science ID 000620541000001
-
Strain-insensitive intrinsically stretchable transistors and circuits
NATURE ELECTRONICS
2021
View details for DOI 10.1038/s41928-020-00525-1
View details for Web of Science ID 000611472500001
-
Swelling-Induced Interface Crease Instabilities at Hydrogel Bilayers
JOURNAL OF ELASTICITY
2021
View details for DOI 10.1007/s10659-020-09810-8
View details for Web of Science ID 000609066200001
-
An Electro-chemo-thermo-mechanical Coupled Three-dimensional Computational Framework for Lithium-ion Batteries
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
2020; 167 (16)
View details for DOI 10.1149/1945-7111/abd1f2
View details for Web of Science ID 000605367700001
-
Interpreting stochastic agent-based models of cell death
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
2020; 360
View details for DOI 10.1016/j.cma.2019.112700
View details for Web of Science ID 000506874400032
-
Three-dimensional explicit finite element formulation for shear localization with global tracking of embedded weak discontinuities
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
2019; 353: 416–47
View details for DOI 10.1016/j.cma.2019.05.011
View details for Web of Science ID 000470960700019
-
Strain- and Strain-Rate-Invariant Conductance in a Stretchable and Compressible 3D Conducting Polymer Foam
MATTER
2019; 1 (1): 205–18
View details for DOI 10.1016/j.matt.2019.03.011
View details for Web of Science ID 000519687800022
-
Diffusion-driven swelling-induced instabilities of hydrogels
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
2019; 125: 38–52
View details for DOI 10.1016/j.jmps.2018.12.010
View details for Web of Science ID 000461728600003
-
Understanding the mechanical link between oriented cell division and cerebellar morphogenesis.
Soft matter
2019
Abstract
The cerebellum is a tightly folded structure located at the back of the head. Unlike the folds of the cerebrum, the folds of the cerebellum are aligned such that the external surface appears to be covered in parallel grooves. Experiments have shown that anchoring center initiation drives cerebellar foliation. However, the mechanism guiding the location of these anchoring centers, and subsequently cerebellar morphology, remains poorly understood. In particular, there is no definitive mechanistic explanation for the preferential emergence of parallel folds instead of an irregular folding pattern like in the cerebral cortex. Here we use mechanical modeling on the cellular and tissue scales to show that the oriented granule cell division observed in the experimental setting leads to the characteristic parallel folding pattern of the cerebellum. Specifically, we propose an agent-based model of cell clones, a strategy for propagating information from our in silico cell clones to the tissue scale, and an analytical solution backed by numerical results to understand how differential growth between the cerebellar layers drives geometric instability in three dimensional space on the tissue scale. This proposed mechanical model provides further insight into the process of anchoring center initiation and establishes a framework for future multiscale mechanical analysis of developing organs.
View details for PubMedID 30758032
-
Evaluation of convective heat transfer coefficient and specific heat capacity of a lithium-ion battery using infrared camera and lumped capacitance method
JOURNAL OF POWER SOURCES
2019; 412: 552–58
View details for DOI 10.1016/j.jpowsour.2018.11.064
View details for Web of Science ID 000456762100063
-
Modeling mechanical inhomogeneities in small populations of proliferating monolayers and spheroids.
Biomechanics and modeling in mechanobiology
2018; 17 (3): 727–43
Abstract
Understanding the mechanical behavior of multicellular monolayers and spheroids is fundamental to tissue culture, organism development, and the early stages of tumor growth. Proliferating cells in monolayers and spheroids experience mechanical forces as they grow and divide and local inhomogeneities in the mechanical microenvironment can cause individual cells within the multicellular system to grow and divide at different rates. This differential growth, combined with cell division and reorganization, leads to residual stress. Multiple different modeling approaches have been taken to understand and predict the residual stresses that arise in growing multicellular systems, particularly tumor spheroids. Here, we show that by using a mechanically robust agent-based model constructed with the peridynamic framework, we gain a better understanding of residual stresses in multicellular systems as they grow from a single cell. In particular, we focus on small populations of cells (1-100 s) where population behavior is highly stochastic and prior investigation has been limited. We compare the average strain energy density of cells in monolayers and spheroids using different growth and division rules and find that, on average, cells in spheroids have a higher strain energy density than cells in monolayers. We also find that cells in the interior of a growing spheroid are, on average, in compression. Finally, we demonstrate the importance of accounting for stochastic fluctuations in the mechanical environment, particularly when the cellular response to mechanical cues is nonlinear. The results presented here serve as a starting point for both further investigation with agent-based models, and for the incorporation of major findings from agent-based models into continuum scale models when explicit representation of individual cells is not computationally feasible.
View details for PubMedID 29197990
-
Area of lineal-path function for describing the pore microstructures of cement paste and their relations to the mechanical properties simulated from mu-CT microstructures
CEMENT & CONCRETE COMPOSITES
2018; 89: 1–17
View details for DOI 10.1016/j.cemconcomp.2018.02.008
View details for Web of Science ID 000433400800001
-
Microstructural origin of resistance-strain hysteresis in carbon nanotube thin film conductors
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2018; 115 (9): 1986–91
Abstract
A basic need in stretchable electronics for wearable and biomedical technologies is conductors that maintain adequate conductivity under large deformation. This challenge can be met by a network of one-dimensional (1D) conductors, such as carbon nanotubes (CNTs) or silver nanowires, as a thin film on top of a stretchable substrate. The electrical resistance of CNT thin films exhibits a hysteretic dependence on strain under cyclic loading, although the microstructural origin of this strain dependence remains unclear. Through numerical simulations, analytic models, and experiments, we show that the hysteretic resistance evolution is governed by a microstructural parameter [Formula: see text] (the ratio of the mean projected CNT length over the film length) by showing that [Formula: see text] is hysteretic with strain and that the resistance is proportional to [Formula: see text] The findings are generally applicable to any stretchable thin film conductors consisting of 1D conductors with much lower resistance than the contact resistance in the high-density regime.
View details for PubMedID 29440431
-
PREFACE: MULTISCALE COMPUTATIONAL ANALYSIS OF COMPLEX MATERIALS
INTERNATIONAL JOURNAL FOR MULTISCALE COMPUTATIONAL ENGINEERING
2018; 16 (4): V-VI
View details for DOI 10.1615/IntJMultCompEng.2018027912
View details for Web of Science ID 000454048100001
-
Computational aspects of morphological instabilities using isogeometric analysis
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
2017; 316: 261-279
View details for DOI 10.1016/j.cma.2016.06.028
View details for Web of Science ID 000395952500012
-
A highly stretchable, transparent, and conductive polymer.
Science advances
2017; 3 (3)
Abstract
Previous breakthroughs in stretchable electronics stem from strain engineering and nanocomposite approaches. Routes toward intrinsically stretchable molecular materials remain scarce but, if successful, will enable simpler fabrication processes, such as direct printing and coating, mechanically robust devices, and more intimate contact with objects. We report a highly stretchable conducting polymer, realized with a range of enhancers that serve a dual function: (i) they change morphology and (ii) they act as conductivity-enhancing dopants in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The polymer films exhibit conductivities comparable to the best reported values for PEDOT:PSS, with over 3100 S/cm under 0% strain and over 4100 S/cm under 100% strain-among the highest for reported stretchable conductors. It is highly durable under cyclic loading, with the conductivity maintained at 3600 S/cm even after 1000 cycles to 100% strain. The conductivity remained above 100 S/cm under 600% strain, with a fracture strain of 800%, which is superior to even the best silver nanowire- or carbon nanotube-based stretchable conductor films. The combination of excellent electrical and mechanical properties allowed it to serve as interconnects for field-effect transistor arrays with a device density that is five times higher than typical lithographically patterned wavy interconnects.
View details for DOI 10.1126/sciadv.1602076
View details for PubMedID 28345040
-
Modeling tumor growth with peridynamics.
Biomechanics and modeling in mechanobiology
2017
Abstract
Computational models of tumors have the potential to connect observations made on the cellular and the tissue scales. With cellular scale models, each cell can be treated as a discrete entity, while tissue scale models typically represent tumors as a continuum. Though the discrete approach often enables a more mechanistic and biologically driven description of cellular behavior, it is often computationally intractable on the tissue scale. Here, we adapt peridynamics, a theoretical and computational approach designed to unify the mechanics of discrete and continuous media, for the growth of biological materials. The result is a computational model for tumor growth that can represent either individual cells or the tissue as a whole. We take advantage of the flexibility provided by the peridynamic framework to implement a cell division mechanism, motivated by the fact that cell division is the mechanism driving tumor growth. This paper provides a general framework for implementing a new tumor growth modeling technique.
View details for DOI 10.1007/s10237-017-0876-8
View details for PubMedID 28124191
-
Quantifying the relationship between cell division angle and morphogenesis through computational modeling.
Journal of theoretical biology
2017; 418: 1-7
Abstract
When biological cells divide, they divide on a given angle. It has been shown experimentally that the orientation of cell division angle for a single cell can be described by a probability density function. However, the way in which the probability density function underlying cell division orientation influences population or tissue scale morphogenesis is unknown. Here we show that a computational approach, with thousands of stochastic simulations modeling growth and division of a population of cells, can be used to investigate this unknown. In this paper we examine two potential forms of the probability density function: a wrapped normal distribution and a binomial distribution. Our results demonstrate that for the wrapped normal distribution the standard deviation of the division angle, potentially interpreted as biological noise, controls the degree of tissue scale anisotropy. For the binomial distribution, we demonstrate a mechanism by which direction and degree of tissue scale anisotropy can be tuned via the probability of each division angle. We anticipate that the method presented in this paper and the results of these simulations will be a starting point for further investigation of this topic.
View details for DOI 10.1016/j.jtbi.2017.01.026
View details for PubMedID 28119022
-
Highly stretchable polymer semiconductor films through the nanoconfinement effect
SCIENCE
2017; 355 (6320): 59-?
Abstract
Soft and conformable wearable electronics require stretchable semiconductors, but existing ones typically sacrifice charge transport mobility to achieve stretchability. We explore a concept based on the nanoconfinement of polymers to substantially improve the stretchability of polymer semiconductors, without affecting charge transport mobility. The increased polymer chain dynamics under nanoconfinement significantly reduces the modulus of the conjugated polymer and largely delays the onset of crack formation under strain. As a result, our fabricated semiconducting film can be stretched up to 100% strain without affecting mobility, retaining values comparable to that of amorphous silicon. The fully stretchable transistors exhibit high biaxial stretchability with minimal change in on current even when poked with a sharp object. We demonstrate a skinlike finger-wearable driver for a light-emitting diode.
View details for DOI 10.1126/science.aah4496
View details for PubMedID 28059762
-
A variational framework to model diffusion induced large plastic deformation and phase field fracture during initial two-phase lithiation of silicon electrodes
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
2016; 312: 51-77
View details for DOI 10.1016/j.cma.2016.05.007
View details for Web of Science ID 000389784000003
-
A highly stretchable autonomous self-healing elastomer
NATURE CHEMISTRY
2016; 8 (6): 619-625
Abstract
It is a challenge to synthesize materials that possess the properties of biological muscles-strong, elastic and capable of self-healing. Herein we report a network of poly(dimethylsiloxane) polymer chains crosslinked by coordination complexes that combines high stretchability, high dielectric strength, autonomous self-healing and mechanical actuation. The healing process can take place at a temperature as low as -20 °C and is not significantly affected by surface ageing and moisture. The crosslinking complexes used consist of 2,6-pyridinedicarboxamide ligands that coordinate to Fe(III) centres through three different interactions: a strong pyridyl-iron one, and two weaker carboxamido-iron ones through both the nitrogen and oxygen atoms of the carboxamide groups. As a result, the iron-ligand bonds can readily break and re-form while the iron centres still remain attached to the ligands through the stronger interaction with the pyridyl ring, which enables reversible unfolding and refolding of the chains. We hypothesize that this behaviour supports the high stretchability and self-healing capability of the material.
View details for DOI 10.1038/NCHEM.2492
View details for Web of Science ID 000376529000020
-
A highly stretchable autonomous self-healing elastomer.
Nature chemistry
2016; 8 (6): 618-624
Abstract
It is a challenge to synthesize materials that possess the properties of biological muscles-strong, elastic and capable of self-healing. Herein we report a network of poly(dimethylsiloxane) polymer chains crosslinked by coordination complexes that combines high stretchability, high dielectric strength, autonomous self-healing and mechanical actuation. The healing process can take place at a temperature as low as -20 °C and is not significantly affected by surface ageing and moisture. The crosslinking complexes used consist of 2,6-pyridinedicarboxamide ligands that coordinate to Fe(III) centres through three different interactions: a strong pyridyl-iron one, and two weaker carboxamido-iron ones through both the nitrogen and oxygen atoms of the carboxamide groups. As a result, the iron-ligand bonds can readily break and re-form while the iron centres still remain attached to the ligands through the stronger interaction with the pyridyl ring, which enables reversible unfolding and refolding of the chains. We hypothesize that this behaviour supports the high stretchability and self-healing capability of the material.
View details for DOI 10.1038/nchem.2492
View details for PubMedID 27219708
-
Understanding geometric instabilities in thin films via a multi-layer model.
Soft matter
2016; 12 (3): 806-816
Abstract
When a thin stiff film adhered to a compliant substrate is subject to compressive stresses, the film will experience a geometric instability and buckle out of plane. For high film/substrate stiffness ratios with relatively low levels of strain, the primary mode of instability will either be wrinkling or buckling delamination depending on the material and geometric properties of the system. Previous works approach these systems by treating the film and substrate as homogenous layers, either consistently perfectly attached, or perfectly unattached at interfacial flaws. However, this approach neglects systems where the film and substrate are uniformly weakly attached or where interfacial layers due to surface modifications in either the film or substrate are present. Here we demonstrate a method for accounting for these additional thin surface layers via an analytical solution verified by numerical results. The main outcome of this work is an improved understanding of how these layers influence global behavior. We demonstrate the utility of our model with applications ranging from buckling based metrology in ultrathin films, to an improved understanding of the formation of a novel surface in carbon nanotube bio-interface films. Moving forward, this model can be used to interpret experimental results, particularly for systems which deviate from traditional behavior, and aid in the evaluation and design of future film/substrate systems.
View details for DOI 10.1039/c5sm02082d
View details for PubMedID 26536391
-
A micromechanical model with strong discontinuities for failure in nonwovens at finite deformations
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
2015; 75-76: 247-259
View details for DOI 10.1016/j.ijsolstr.2015.08.018
View details for Web of Science ID 000363079800020
-
The reduced basis method in all-electron calculations with finite elements
ADVANCES IN COMPUTATIONAL MATHEMATICS
2015; 41 (5): 1035-1047
View details for DOI 10.1007/s10444-014-9374-z
View details for Web of Science ID 000365740300005
-
A Complex Variable Solution Based Analysis of Electric Displacement Saturation for a Cracked Piezoelectric Material
JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME
2014; 81 (9)
View details for DOI 10.1115/1.4027834
View details for Web of Science ID 000355556000006
-
Three-dimensional finite elements with embedded strong discontinuities to model failure in electromechanical coupled materials
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
2014; 273: 143-160
View details for DOI 10.1016/j.cma.2014.01.021
View details for Web of Science ID 000334088900008
-
A homogenization approach for nonwoven materials based on fiber undulations and reorientation
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
2014; 65: 12-34
View details for DOI 10.1016/j.jmps.2013.12.011
View details for Web of Science ID 000334132300002
- A homogenization approach for nonwoven materials based on fiber undulations and reorientation Journal of the Mechanics and Physics of Solids. Accepted for publication 2014
-
A marching cubes based failure surface propagation concept for three-dimensional finite elements with non-planar embedded strong discontinuities of higher-order kinematics
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
2013; 96 (6): 339-372
View details for DOI 10.1002/nme.4546
View details for Web of Science ID 000325687400001
-
A strong discontinuity approach on multiple levels to model solids at failure
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
2013; 253: 558-583
View details for DOI 10.1016/j.cma.2012.07.005
View details for Web of Science ID 000313134600037
- 3D finite elements to model electromechanical coupled solids at failure. 2013
- Modeling reorientation phenomena in nonwoven materials with random fiber network microstructure. 2013
- An analysis of the exponential electric displacement saturation model in fracturing piezoelectric ceramics. Technische Mechanik. 2012; 32: 53-69
- Homogenization of random elastic networks with non-affine kinematics. 2012
- New three-dimensional finite elements with embedded strong discontinuities to model solids at failure. 2012
- Modeling quasi-static crack growth with the embedded finite element method on multiple levels. 2012
- All-electron calculations with finite elements. 2012
-
New finite elements with embedded strong discontinuities for the modeling of failure in electromechanical coupled solids
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
2011; 200 (1-4): 141-161
View details for DOI 10.1016/j.cma.2010.07.021
View details for Web of Science ID 000285815300011
- Microstructural driven computational modeling of polymers. 2011
- Finite element solution of the Kohn-Sham equations. 2011
- A strong discontinuity based adaptive refinement approach for the modeling of crack branching. 2011
- Modeling crack micro-branching using finite elements with embedded strong discontinuities. 2010
-
Numerical simulation of dynamic fracture using finite elements with embedded discontinuities
INTERNATIONAL JOURNAL OF FRACTURE
2009; 160 (2): 119-141
View details for DOI 10.1007/s10704-009-9413-9
View details for Web of Science ID 000271749500002
-
Finite elements with embedded branching
20th Annual Robert J Melosh Conference
ELSEVIER SCIENCE BV. 2009: 280–93
View details for DOI 10.1016/j.finel.2008.10.012
View details for Web of Science ID 000263792100006
- Numerical modeling of dynamic fracture. 2009
-
New finite elements with embedded strong discontinuities in the finite deformation range
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
2008; 197 (33-40): 3138-3170
View details for DOI 10.1016/j.cma.2008.02.021
View details for Web of Science ID 000257666400030
- Numerical simulation of dynamic fracture using finite elements with embedded discontinuities. Report No. UCB/SEMM-2008/01, Department of Civil and Environmental Engineering 2008
-
On configurational compatibility and multiscale energy momentum tensors
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
2007; 55 (5): 980-1000
View details for DOI 10.1016/j.jmps.2006.11.002
View details for Web of Science ID 000246942500005
-
Recent developments in the formulation of finite elements with embedded strong discontinuities
IUTAM Symposium on Discretization Methods for Evolving Discontinuities
SPRINGER. 2007: 105–122
View details for Web of Science ID 000251312200006
- New finite elements with embedded strong discontinuities for the modeling of failure in solids. Ph.D. Thesis, Department of Civil and Environmental Engineering 2007
- Application of differential topology for the derivation of compatibility conservation laws in mechanics. M.A. Thesis, Department of Mathematics, University of California 2006
- Finite elements with strong discontinuities. Qualifying Report, Department of Civil and Environmental Engineering 2005
- Analogy model for the axisymmetric elastic edge bending problem in shells of revolution based on Geckeler’s approximation. 2004
- An arbitrary Lagrangian-Eulerian finite element formulation for dynamics and finite strain plasticity models. M.Sc. Thesis, Computational Mechanics of Materials and Structures, University of Stuttgart. 2003
- Elastic stress analysis of axisymmetric discontinuities in shells of revolution by an effective ring analogy model. 2003