Elias Aifantis

Professor of Mechanics, Department of Civil Engineering, Aristotle University, Thessaloniki, GR-54124, Greece

[Director, Laboratory of Mechanics and Materials, School of Engineering ; [email protected];

http://users.auth.gr/users/0/3/022730/public_html/index3.htm]

■ Personal Data

Date/Place of Birth: 10 October 1950, Greece; Citizenship: Hellenic/US

Private address: 2 Olympiados Str., N. Krini, GR-55132, Thessaloniki, Greece. Tel.: +30-2310-444386

1010 College Avenue, MI-49931, Houghton, USA. Tel.: +1-906-482-3483

■ Academic Degrees

 National Technical University of Athens, Mining and Metallurgy (Diploma/BS-MS, 1973)

 University of Minnesota, Chemical Engineering and Materials Science-Mechanics (Ph.D, 1975)

■ Academic Posts

 University of Minnesota (Instructor 1975-76)

 University of Illinois at Urbana-Champaign (Assistant Professor 1976-80)

 University of Minnesota (Visiting Professor 1980-82)

 Michigan Tech Univ (Professor 1982-2000); Distinguished Research Professor 2000-2010; Emeritus 2010-)

 Aristotle University of Thessaloniki (Professor after special honorary invitation/metaklisi, 1990-)

 King Abdulaziz University, Jeddah (Distinguished Adjunct Professor 2011- 2014)

 ITMO Univ/Int Lab of Modern Functional Materials, St. Petersburg (Distinguished Visiting Professor 2014, 2015)

 BUCEA/Beijing Univ. of Civil Engineering and Architecture, Beijing (Distinguished Visiting Professor 2015, 2016)

■ Academic Distinctions

 Fellowship Award for 1 mo Visit to USSR/US Academy of Sciences, 1986

 MTU Research Award, Michigan Tech Univ, Houghton/MI, 1993

 Fellowship Award for 1 mo Visit to Japan/Japanese Government, 1996

 ASME’s Koiter Award, 2000 (1st runner up - Lost by one vote; 2 of his greek colleagues in US voted for Maier)

 ASME/ASCE/SES Symposium honoring his 55th birthday, 1-3 June 2005, Baton Rouge/USA [Appendix II]

 Selected for ASM’s Author Award (for his article in Metal. Mater. Trans. A 42, 2985-2998, 2011)

 Acknowledged in G.A. Maugin’s Continuum Mechanics Through the 20th Century: A Coincise Historical

Perspective, Springer, 2013. [Chapter 10.6.3/Greece: P.S. Theocaris, P.D. Panagiotopoulos, E.C. Aifantis, G.M.

Lianis.]

 Listed in ISI Web of most highly cited authors in the world: ENGINEERING (3rd entry. A0086-2010-N out of 262)

 KACST Award/King Abdulaziz University, Jeddah-Saudi Arabia, 2013

 Distinguished Foreign Scientist Fellowship Award/Southwest Jiaotong University, Chengdu-China, 2014

 Aifantis International Symposium honoring his 65th birthday, 4-9 October, 2015, Antalya/Turkey [Appendix II]

 Fray International Sustainability Award (along with Nobel Laureate El-Ichi Negishi)/Flogen Star Outreach, 2015

■ Teaching and Research

 Undergraduate Courses in Statics and Dynamics; Strength and Mechanics of Materials; Elasticity and Visoelasticity;

Plasticity and Damage; Creep and Fracture

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 Graduate Courses in Continuum Mechanics and Thermodynamics; Mechanical Behavior: Metals – Rocks/Soils –

Polymers – Biomaterials; Materials Science: Dislocations – Diffusion – Phase Transformations; Micromechanics and

Nanomechanics; Nanosciences and Nanotechnologies

 Training Seminars/Course Modules on the above topics in Summer Schools and Multi-University Curricula

 Interdisciplinary Research on Macro/Micro/Nano Mechanics of Materials and Structures; Diffusion and Flow

through Deformable Porous Media; Stress Corrosion Cracking and Environmental Damage; Phase Transitions and

Interfaces; Material Instabilities: Dislocation Patterning/Shear Banding/Damage Localization; Coupled Continuum

Mechanics of Structured Natural Materials: Soils/Rocks/Wood/Biomaterials; Thermo-electro-chemo-mechanics of

Engineering Materials: Metals/Polymers/Concrete/Composites; Novel Nanostructured Materials/Structures and

Devices: Nanoparticles/Nanotubes/Nanowires, Nanofibers/Nanobeams/Nanoplates, MEMS/NEMS, Li-ion Batteries

(LiBs), Light Emitting Diodes (LEDs), Medical Implants, Nano-decorated tissues and cells

 Coined in his publications the terms Double Diffusivity/Porosity, Chemomechanics, Material Instabilities,

Dislocation Patterning, Gradient Plasticity, Nanomechanics, NanoNeuroMechanics

■ Funding I (Last 5 years)

 PI: Greek National Strategic Reference Framework (NSRF): “Funding of Research Projects Positively Reviewed in

the 5th ERC Grant Schemes Call: Internal Length Gradient Mechanics Across Scales and Materials: Theory,

Experiments and Applications/IL-GradMech-ASM”, 2013-2015, 797 kEuros

 PI: General Secretariat of Research and Technology (GSRT): “ARISTEIA II: Size Effects in Deformation and

Electromechanical Problems/SEDEMP”, 2014-2015, 283 kEuros

 Co-PI: Multi-investigator EU project: ERANET-RUS “STProjects-219/NanoPhase: Shift of the phase equilibria in

nanograined materials”, 2012-2015, 207 kEuros

 Co-PI: Multi-investigator project from the Greek Ministry of Education: “THALES INTERMONU: Conservation

and Restoration of Monuments of Cultural Heritage”, 2012-2015, 600 kEuros

 Host: K.E. Aifantis – the youngest recipient ever with an ERC Starting Grant (MINATRAN 211166, 2008-2013,

1.130k Euros); A.E. Romanov - an international expert on defects in solids with a IIF Marie - Curie Senior Fellowship

Grant (PIIF-GA-2008-220419, 2009-2011, 200 kEuros)

■ Funding II (15 years; 1992-2007)

 Director/Co-Director of Human Capital and Research Training Network projects (HCM/TMR/RTN), INTAS

projects, Euratom projects (REVISA, LISSAC), as well as the General Secretariat of Research and Technology

(GSRT) projects (PENED, PYTHAGORAS), as follows: Coordinator of 3 European Research Training Networks:

HCM Fellowships in Mechanics of Materials /ERBCHBGCT 920041, 1992-1996, 240 kEuros; TMR Network on

Spatiotemporal Instabilities in Deformation and Fracture/ERBFMRXCT 960062, 1996-2002, 1760 kEuros; RTN

Network on Deformation and Fracture Instabilities in Novel Materials and Processes/HPRNCT-2002-00198, 2002-

2007, 1500 kEuros; Partner of RTN Network on Degradation and Instabilities in Geomaterials with Application to

Hazard Mitigation/HPRNCT-2002-00220, 2002-2006, 1600 kEuros. Coordinator of 3 INTAS Projects (INTAS-93-

3213; INTAS-93-3213 – extension; INTAS-94-4380) in addition to PENED and PYTHAGORAS Grants from the

Greek Government. Partner of 2 European projects on Nuclear Reactor Safety (REVISA/FI4S-CT96-0024, 1997-

2000, and LISSAC/FIKS-CT1999-00012, 2000-2002, coordinated by J. Devos/France and R. Krieg/Germany

respectively) by focusing on size effects and component failure using ECA’s theory of gradient thermoplasticity and

damage. The total amount of the INTAS/PENED/PYTHAGORAS and REVISA/LISSAC projects for ECA’s Lab

was about 1 million Euros.

 PI/Co-PI of a number of US projects supported by NSF, ARMY, ARO/NATO and other International Organizations

(China, Japan, Saudi Arabia) totalling ~12 million USD. The most recent grant from US/NSF (Novel Experiments

and Models for the Nanomechanics of Polymeric and Biological Nanofibers, NSF NIRT Grant DMI #0532320, 2004-

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2008, 1.3M USD) was carried out in collaboration with Michigan Tech, U. of Illinois (I. Chasiotis), U. of Virginia

(L. Zhigilei), U. of Minnesota (R. Ballarini), and Case Western (S. Eppel).

 Co-Founder of a Degree Awarding Graduate Program on Nanosciences and Technologies, at Aristotle University in

Greece (http://nn.physics.auth.gr/) and of similar programs in US: NUE – Undergraduate Exploration of Nano-

Science, Applications, and Societal Implications; Enterprise/Minor in Nanoscale Science and Engineering at

Michigan Tech (http://nano.mtu.edu/nueindex.htm; http://nano.mtu.edu/nanominor.htm).

■ PhD Students/Postdocs

 Advisor/Co-advisor of ~20 PhDs and supervisor of ~30 postdocs. Many of these hold university positions in the US,

EU, Russia and China. Examples include former PhDs Doug Bammann (Professor at Mississippi State), Hussein Zbib

(Professor and former Chair at Washington State) and David Unger (Professor, Univ of Evansville); former

postdocs/visiting scholars Andrzej Neimitz (Professor at Kielce University of Technology), Oleg Naimark (Professor

at Perm State Univ), Chongqing Ru (Professor at University of Alberta), Alexey Romanov (Professor and Director at

ITMO University), Harm Askes (Professor and Head at Univ of Sheffield), Michael Zaiser (Professor at the Univ of

Erlangen-Nürnberg) and Kaiyu Xu (Professor at Shanghai Univ). Four of his more recent PhD students at Aristotle

Univ - A. Konstantinidis/ M. Avlonitis/G. Efremidis and I. Mastorakos - are assistant professors at greek universities

(Thessaloniki/Corfu/Volos) and at Clarkson/US, respectively. Two of his recent postdocs K. Moutsopoulos and A.

Kalampakas are associate professor (Democritus Univ of Thrace) and assistant professor (American Univ of the

Middle East), respectively. Former PhD students in the US (R. Wilson, P. Taylor, T. Webb, X. Zhu, J. Huang) hold

key positions in National Labs and Research Government Organizations.

■ Diploma/Masters Students and Visiting Scientists

 Supervisor of ~15 Diploma/Master theses and of ~20 young researchers/visiting scientists in joint university projects.

Examples of those holding academic positions in US include I. Chasiotis (Professor at Univ of Illinois at Urbana-

Champaign) and K. Kalaitzidou (associate professor at Georgia Tech). Other examples of former postdocs and shortterm

(3-9 mo) visitors supported by the TMR/RTN/INTAS programs, and currently holding academic positions,

include M. Gutkin/St. Petersburg, M. Seefeldt/Leuven, M. Lazar/Darmstadt, X. Zhang/Chengdu, G. Ferro/Torino, P.

Cornetti/Torino, C. di Prisco/Milano, N. Pugno/Trento, G. Ribarik/Budapest, J.V. Andersen/Paris.

 Other young scientists/short-term visitors who spent time in his Lab and currently hold academic positions include A.

Nikitas (Univ of Huddersfield), N. Nikitas (Univ of Leeds), N.-H. Zhang (Univ of Shanghai), H. Xu (Shanghai

Jiaotong Univ), Y. Chen/R. Yang (CAS/LNM – Beijing), A. Chattopadhyay (Aston Univ), M. Mousavi (Aalto Univ).

■ Collaborators/Distinguished Visitors

 Senior long-term collaborators who conducted joint projects or research visits in his Lab include J. Kratochvil

(Prague), P. Perzyna (Warsaw), Z. Mroz (Warsaw), D. Beskos (Minnesota/Patras), N. Triantafyllidis (Ann

Arbor/Paris), E. Gdoutos (Xanthi/Northwestern), I. Vardoulakis (Minnesota/Athens), Y. Dafalias (Davis), N. Aravas

(Pennsylvania/Volos), H. Mühlhaus (CSIRO/Queensland), G. Frantziskonis (Arizona), G. Voyiadjis (Louisiana), A.

Varias (Malmö), I. Groma (Budapest), J. Willis/N. Fleck (Cambridge), G. Maugin (Paris), A. Carpinteri (Torino), R.

de Borst (Delft/Glasgow/Sheffield), R. Ballarini (Case Western/Minnesota/Houston), S. Forest (Paris), P. Steinmann

(Kaizerslautern/Erlangen-Nürnberg).

 World-known contributors who were hosted in his Lab in US include Clifford Truesdell, Dan Drucker, Cemal

Eringen, Jerry Ericksen, Jim Serrin, Frank Nabarro, as well as the Chemistry Nobel Laureate Ilya Prigogine. At

Aristotle University he hosted, among others, A. Ngan (Hong Kong), J. Goddard (San Diego), Yilong Bai (Beijing),

Gerard Maugin (Paris) and Constantino Tsallis (Rio).

■ Seminars/Lectures and Conferences

 Invited in ~500 occasions to speak in conferences, universities, and research laboratories in the US, Europe, Former

Soviet Union, Russia, Australia, Japan, South Africa, Brazil, Saudi Arabia, China. The majority of his lectures in

conferences and symposia/workshops were invited, keynote and plenary. Examples of plenary lectures in the last 10

years include: Plenary Lecture in the 16th European Conference on Fracture/ECF16, 2-8 July 2006,

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Alexandroupolis/Greece; Plenary Lecture in the 6th South African Conference on Computational and Applied

Mechanics/SACA-2008, 26-28 March 2008, Cape Town/South Africa; Plenary Lecture in the 10th Asia-Pacific

Conference on Engineering Plasticity and its Applications/AEPA-2010, 15-17 November 2010 Wuhan/China;

Plenary Lecture in the 5th International Conference on Materials Science and Condensed Matter Physics/MSCMP-

2010, 13-17 September 2010, Chisinau/Moldova; Plenary Lecture in the 7th WSEAS International Conference on

Continuum Mechanics, 14-17 July 2012, Kos/Greece; Plenary Lecture in the 12th International Conference of

Numerical Analysis and Applied Mathematics/INCAAM-2014, 22-28 September 2014, Rhodes/Greece; Plenary

Lecture in the Shechtman International Symposium, 29 June – 4 July 2014, Cancun/Mexico; Plenary Lecture in the

1st Sino-Russian-Belarusian Joint Scientific-Technical Forum, 15-17 September 2015, Beijing/China; and a

forthcoming Plenary Lecture in the XLIV International Conference in Advanced Problems in Mechanics, June 27-

July 2 2016, St. Petersburg.

 Organizer/Co-organizer of ~20 International Conferences/Symposia/Workshops and Member of Organizing

Committees of ~50 Scientific Meetings. Examples include: E.C. Aifantis and J.P. Hirth, International Symposium on

the Mechanics of Dislocations, 50 years since the Discovery of Dislocations with a Tribute to J.D. Eshelby, 28-31

August 1983, Houghton, Michigan/USA; E.C. Aifantis, International Conference on Mechanics, Physics and

Structure of Materials: A Celebration of Aristotle’s 23 Centuries, 19-24 August 1990, Thessaloniki/Greece; E.C.

Aifantis, 2nd Euroconference and International Symposium on Materials Instabilities in Deformation and Fracture,

31 August – 4 September 1997, Thessaloniki/Greece; E.C. Aifantis, 5th EuroMech Solid Mechanics Conference

(ESMC-5), 17-22 August 2003, Thessaloniki/Greece; E.C. Aifantis, 1st World Symposium on Multiscale Material

Mechanics and Engineering Sciences, Dedicated to the Memory of Frank Nabarro, Edward Hart and Ronald Rivlin,

29 April – 3 May 2007, Thessaloniki/Greece; E. Meletis, E.C. Aifantis and E. Kaxiras, 1st International Conference:

From Nanoparticles and Nanomaterials to Nanodevices and Nanosystems (1st IC4N-2008), 16-18 June 2008,

Halkidiki Penninsula/Greece; Y. Dafalias, E.C Aifantis and L. Toth, Symposium on Generalized Granular

Mechanics, 2016 EMI International Conference, 25-27 October 2016, Metz/France; F. Kongoli, E.C. Aifantis, H.

Wang and T. Zhu, YANG International Symposium on Multiscale Material Mechanics and Multiphysics and

Sustainable Applications (in honor of Life-time Achievements of Prof. Wei Yang – President of Natural Science

Foundation of China), 6-10 November 2016, Hainan Island/China.

 Symposia Honoring ECA’s Contributions: Joint ASME/ASCE/SES Symposium honoring his 55th birthday, 1-3 June

2005, Baton Rouge, USA [Organizers: D.J. Bammann, H.M. Zbib, P. Sofronis]; Flogen Star Outreach Symposium

honoring his 65th birthday, 4-9 October 2015, Antalya, Turkey [Organizers: F. Kongoli, S. Bordas, Y. Estrin.]

■ Editorships and Editorial Boards

 Editor/Co-Editor: 12 Books/Special Journal Issues and Conference Proceedings. Examples include: E.C. Aifantis and

L. Davison, Media with Microstructures and Wave Propagation, Special Issue of Int. J. Engng. Science 212, 961-

1224, 1984; E.C. Aifantis and J.P. Hirth, The Mechanics of Dislocations [248 pages], ASM, Metals Park, 1985; E.C.

Aifantis and J. Gittus, Phase Transformations [302 pages], Elsevier Appl. Sci. Publ., London-New York, 1986.

 Editor-in-Chief: J. Mechanical Behavior of Materials (ISSN 0334-8938); Honorary Editor of Computer and

Experimental Simulations in Engineering and Science (ISSN 1791-3829).

 Advisory/Editorial Board Member: Reviews on Advanced Materials Science (ISSN 1605-8127); Materials Physics

and Mechanics (ISSN 1605-8119); Acta Mechanica Solida Sinica (ISSN 0894-9166); Mechanical Sciences (ISSN

2191-9151); J. Control Engineering and Technology (ISSN 2223-2036); Open Mechanics Journal (ISSN 1874-

1584), J. Adv. Microelectronic Engng. (ISSN 2327-7599); Open Conf. Proc. J. (ISSN 2210-2892); Scientific and

Technical Journal of Information Technologies, Mechanics and Optics (ISSN 2226-1494).

 Former Editorial Boards: Acta Mechanica (ISSN 0001-5970), J. Nano Research (ISSN 1662-5250); Mechanics of

Cohesive-Frictional Materials (ISSN 1099-1484); Numerical and Analytical Methods in Geomechanics (ISSN 106-

222).

■ Publications/Citations

 Published over 550 articles in scientific journals, book chapters/proceedings, and technical reports

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 Cited: ~8380 times/45 h-index (ISI); ~8370 times/44 h-index (Scopus); ~13450 times/57 h-index (Google Scholar)

 ISIHighlyCited.com: Included in the 2001 ISI Web of knowledge list of most highly cited authors in ENGINEERING

(3rd entry no. A0086-2010-N out of 262)

 3 most Highly Cited single authorship articles: E.C. Aifantis, On the microstructural origin of certain inelastic

models, J. Engng. Mat. Tech. 106, 326-330, 1984. [ISI: 582, Scopus: 758; Google Scholar: 1142; 5th mostly cited

article of the Journal]; E.C. Aifantis, The physics of plastic deformation, Int. J. Plasticity 3, 211-247, 1987. [ISI: 521,

Scopus: 486; Google Scholar: 814; 7th mostly cited article of the Journal]; E.C. Aifantis, On the role of gradients in

the localization of deformation and fracture, Int. J. Engrg. Sci. 30, 1279-1299, 1992. [ISI: 359, Scopus: 378; Google

Scholar: 580; 10th mostly cited article of the Journal.]

 12 Most Cited Articles [Full List of Publications in Appendix I]

1. E.C. Aifantis, On the microstructural origin of certain inelastic models, Transactions of ASME, J. Engng. Mat. Tech. 106,

326-330 (1984). [Citations: 758/Scopus, 582/ISI, 1142/Google Scholar]

2. E.C. Aifantis, The physics of plastic deformation, Int. J. Plasticity 3, 211-247 (1987). [Citations: 486/Scopus, 521/ISI,

814/Google Scholar]

3. E.C. Aifantis, On the role of gradients in the localization of deformation and fracture, Int. J. Engrg. Sci. 30, 1279-1299 (1992).

[Citations: 378/Scopus, 359/ISI, 580/Google Scholar]

4. H.B. Muhlhaus and E.C. Aifantis, A variational principle for gradient plasticity, Int. J. Solids Struct. 28, 845-857 (1991). [Citations:

Scopus not listed, 433/ISI, 694/Google Scholar]

5. E.C. Aifantis, Update on a class of gradient theories, Mechanics of Materials 35, 259-280 (2003). [Citations: 232/Scopus,

215/ISI, 281/Google Scholar]

6. E.C. Aifantis, Strain gradient interpretation of size effects, Int. J. Fract. 95, 299-314 (1999). [Citations: 221/Scopus, 171/ISI,

305/Google Scholar]

7. H.M. Zbib and E.C. Aifantis, On the localization and postlocalization behavior of plastic deformation - I: On the initiation of

shear bands, Res Mechanica 23, 261-277 (1988). [Citations: 188/Scopus, 177/ISI, 274/Google Scholar]

8. N. Triantafyllidis and E.C. Aifantis, A gradient approach to localization of deformation - I. Hyperelastic materials, J. of

Elasticity 16, 225-238 (1986). [Citations: 192/Scopus, 192/ISI, 297/Google Scholar]

9. M. Ke, S.A. Hackney, W.W. Milligan, and E.C. Aifantis, Observation and measurement of grain rotation and plastic strain in

nanostructured metal thin films, Nanostructured Materials 5, 689-698 (1995). [Citations: 178/Scopus, 183/ISI, 236/Google

Scholar]

10. C.Q. Ru and E.C. Aifantis, A simple approach to solve boundary value problems in gradient elasticity, Acta Mechanica 101,

59-68 (1993). [Citations: 168/Scopus, 165/ISI, 248/Google Scholar]

11. E.C. Aifantis, On the problem of diffusion in solids, Acta Mechanica 37, 265-296, 1980. [Citations: 173/Scopus, 168/ISI,

267/Google Scholar]

12. H. Askes and E.C. Aifantis, Gradient elasticity in statics and dynamics: An overview of formulations, length scale

identification procedures, finite element implementations and new results, Int. J. Solids Struct. 48, 1962-1990, 2011.

[Citations: 137/Scopus, 124/ISI, 185/Google Scholar]

 Research Topics Pioneered by ECA and Discussed in Books Published by Other Distinguished Authors: Over the past

three decades, ECA’s research has stimulated the organization of various specialized workshops/conferences and the

publication of journal special issues and book chapters. Chapter 89 of the book by M. Gurtin/E. Fried/L. Anand (The

Mechanics and Thermodynamics of Continua, Cambridge Univ Press, UK, 2010) is dedicated to his theory of

“gradient plasticity” and Chapter 6 of the book by Nobel Laureate I. Prigogine and G. Nicolis (Exploring

Complexity, Freeman, New York, 1989) is dedicated to his approach (with D. Walgraef) on “dislocation patterning”.

A discussion of the Walgraef-Aifantis (W-A) model on PSBs formation is also provided in Chapter 2.6 of a book by

S. Suresh (Fatigue of Materials, Cambridge Univ Press, UK, 1991) and in Chapter 2.7.3 of the 2nd Edition, 2001. His

theory on “gradient elasticity” as applied to elimination of singularities from dislocation lines is the subject of

Chapter 3.1.1 of another recent book by M.Yu. Gutkin and I.A. Ovid’ko (Plastic Deformation in Nanocrystalline

Materials, Springer-Verlag, Berlin-Heidelberg-New York, 2004). The W-A model (as well as the role of gradients in

plastic instabilities) is also discussed extensively in a recent book by N. Ghoniem and D. Walgraef (Instabilities and

Self-Organization in Materials, Oxford Univ Press, UK, 2008). Finally, a brief discussion of his research

contributions was included in Chapter 10.6.3 in a book by G.A. Maugin (Continuum Mechanics Through the 20th

Century: A Coincise Historical Perspective, Springer, 2013).

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■ Research Interdisciplinarity / Innovation

 ECA’s broad research background and international collaborations have led to several world-wide recognized

interdisciplinary contributions in the mechanics and physics of materials and structures. His work – combining

fundamental theory, mathematical modeling, numerical simulations and experiments – has found numerous

applications in various disciplines across engineering sciences and departments, including mining and civil, materials

and mechanical, chemical and electrical engineering. This wide spectrum of research activity is partly due to a

multifaceted education (first Diploma in mining and metallurgy/NTU-Athens; PhD in mechanics – chemical

engineering and materials science/U of Minnesota), as well as to multiple academic posts (first in the Dept of

Theoretical and Applied Mechanics/U of Illinois-Urbana; later in the Dept of Chemical Engineering and Materials

Science/U of Minnesota and the Dept of Mechanical Engineering – Engineering Mechanics/Michigan Tech; and,

finally, in the Dept of Civil Engineering/Aristotle Univ of Thessaloniki). The areas that his theories and models have

been applied vary from traditional (flow/diffusion through deformable fissured rocks; damage/failure of geomaterials,

asphalts and concrete; deformation and fracture of metals, polymers and composites) to emerging ones

(nanopolycrystals and metallic glasses; MEMS/NEMS and optoelectronic films; biomaterials and tissues/bonecollagen-

soft tissues-cells).

 He revised and brought ideas of van der Waals (non-monotone equations of state and higher-order density gradients)

and Maxwell (diffusive drag and higher-order temperature gradients), as well as of Landau (order parameter and nonconvex

free energy) and Prigogine (non-equilibrium thermodynamics and self-organization) into the mechanics of

materials and structures within a multiscale/multiphysics setting. This allowed for the development of new

approaches to address unresolved issues (spatio-temporal pattern formation, interpretation of size effects, elimination

of stress/strain singularities) in this field. The topics/terms of “double diffusivity” and “double porosity”, “stressassisted

diffusion”, “material instabilities”, “dislocation patterning”, “chemomechanics”, and “nanomechanics” were

first introduced/quoted and dealt with in his publications. He pioneered the approach of “gradient plasticity” by

providing a method to calculate shear band widths and spacings, and eliminate the mesh-size dependence of finite

element calculations in the strain softening regime. He simplified and popularized the approach of “gradient

elasticity” by providing the first non-singular solutions for dislocation lines and crack tips. These results, which

become increasingly important as the specimen/component dimensions reduce down to micron and nano levels, can

now be checked against laboratory and numerical tests which are possible with advanced experimental probes and

powerful computers. Variants of his gradient theories in elasticity, plasticity and damage are extensively used today

for interpreting size effects across the scale spectrum, as well as for fitting experimental data on the mechanical

behavior of micro/nano-objects (micro/nanopillars, nanobeams, nanotubes).

 More recently, he enriched the aforementioned gradient models with randomness effects, in order to assess the

competition between deterministic gradients and stochastic terms due to internal stress fluctuations. He was among

the first to introduce the techniques of bifurcation, stability and self-organization into the field of material mechanics

and continues along these lines by introducing new tools recently developed in the field of nonlinear and statistical

physics. As examples, reference is made to his recent articles on non-extensive thermodynamics and Tsallis qstatistics,

as well as on fractional calculus and fractal media for characterizing deformation, damage and failure of

nanocrystalline (NC) and ultrafine grain (UFG) materials, as well as bulk metallic glasses (BMGs). Most recently, he

has considered gradient multiphysics couplings (gradient thermo-chemo-mechanics and opto-electro-mechanics) for

these novel “structural” materials and extended his work to encompass “energetic” materials, including “defect-free”

nanolayers for next generation light emitting diodes (LEDs) and “strain relief” nanostructured electrodes for

rechargeable Li-ion batteries (LiBs). He is also exploring the applicability of these techniques for addressing the

mechano-chemo-electrical response of neural cells/neurons.

 The above research activity was carried out in collaboration with former students and postdocs, as well as senior

scientists in the US, Europe, Russia and China. Co-authors include profound mathematicians (Jim Serrin/Minnesota,

James Hill/Australia, Vasily Tarasov/Moscow), mechanicians (Gerard Maugin/Paris, Rene de Borst/Glasgow-Delft,

Hans Muhlhaus/Germany), physicists (Daniel Walgraef/Brussels, Alexey Romanov/St. Petersburg, Jeff de

Hosson/The Netherlands), and materials scientists (Bill Gerberich/Minnesota, Ladislas Kubin/France, Yuri

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Estrin/Australia). A number of leading material mechanics contributors in academia have been his students (Doug

Bammann/Mississippi, Hussein Zbib/Washington, Ioannis Chasiotis/Urbana) or postdocs (Harm Askes/Sheffield,

Mike Zaiser/Edinburgh-Erlangen, Alexey Romanov/St. Petersburg, Chongqing Ru/Alberta, Michail Gutkin/St.

Petersburg).

 In the last five years major funding of ~ 3 million Euros has been awarded to his Lab through the European Research

Council (ERC) and the Greek General Secretariat of Research and Technology (GSRT) to establish an International

Research Center on “Materials and Processes across Scales and Disciplines” at the Aristotle University of

Thessaloniki (AUT), even though this effort is currently facing difficulties due to local financial constraints imposed

on the country. Nevertheless, nonlocal interactions with US (Civil Engineering and Engineering Mechanics at the

University of Arizona), China (State Key Lab of Nonlinear Mechanics of the Chinese Academy of Sciences and

Beijing University of Civil Engineering and Architecture), Russia (International Lab of Modern Functional Materials

at ITMO University, St. Petersburg), are successfully carried out, in addition to former collaborations with EU

Laboratories.

■ Research Milestones / Impact

 In the mid 1970’s – while at the Dept of Theoretical and Applied Mechanics of the Univ of Illinois at Urbana – ECA

started with his students the effort of bringing into the field of solid mechanics ideas from diffusion theory, chemical

reactions, and nonlinear physics. They developed “stress-assisted diffusion” theories with applications to hydrogen

embrittlement and stress corrosion cracking, “double diffusivity and 2-temperature” theories for modeling

simultaneous transport in the bulk and grain boundaries of polycrystals, as well as “double porosity” theories for

modeling fluid flow in undeformable and deformable fractured rocks with applications to consolidation and

subsidence. This initial work on internal mass transport motivated the concept of viewing a stressed solid at the

macroscale as an active medium whose deformation is governed by the production/annihilation and transport of

defect populations (dislocations, disclinations), which interact with the defect-free material regions according to the

laws of microscopic physics. His robust and inspiring models of gradient dislocation dynamics and gradient plasticity

that became quite popular later on, were essentially based on the above idea.

 In the early 1980’s (jointly with Jim Serrin), while at the University of Minnesota, he revisited Maxwell’s equal area

rule and van der Waals theory of fluid interfaces within a strictly mechanical framework by incorporating higher

order density gradients in the non-monotonous constitutive expression for the interfacial stress tensor. Among the

results were the relocation of Maxwell’s line (i.e. the establishment of non-universality of Maxwell’s rule for liquidvapor

transitions) and the derivation of transition, reversal and periodic solutions for fluid/solid microstructures. This

work motivated, in part, a number of articles in applied mathematics (Coleman, Gurtin, Slemrod, Truskinovski and

others) in the area of non-convex free energy and continuum phase transitions.

 In the mid 1980’s (jointly with Daniel Walgraef), while at Michigan Tech, he developed the first generation models

to interpret self-organization of dislocations and deformation patterning. The Walgraef-Aifantis (W-A) model was the

first to predict widths and spacings of the layered dislocation structure of the persistent slip bands observed in

fatigued crystals as discussed, for example, in Chapter 6 of the Nobel Laureate’s Ilya Prigogine’s book “Exploring

Complexity”, Freeman, New York (1989). This work inspired a steady stream of follow-up efforts on dislocation

patterning, including recent papers on discrete and density-based dislocation dynamics simulations (e.g. Kubin,

Ghoniem, Zbib, Groma, El-Azab, Zaiser, Ngan and others). Most notably, the W-A model has recently been used by

leading geophysicists/geomechanics researchers to interpret crack patterns in granular materials (A. Ord and B.

Hobbs, Fracture pattern formation in frictional, cohesive, granular material, Phil. Trans. R. Soc. A 368, 95-118, 2010

[One contribution of 17 to a Theme Issue “Patterns in our Planet: Applications of Multi-scale Non-equilibrium

Thermodynamics to Earth-system Science”] ).

 In the mid and late 1980’s, while at Michigan Tech, he proposed the first gradient plasticity model to predict the

thickness of shear bands and eliminate the mesh-size dependence of finite element (FE) calculations in the strain

softening regime. This was used in FE codes developed by de Borst, Tomita and others to solve large-scale

engineering problems for which classical plasticity did not work. Other gradient plasticity models, such as those

proposed by Fleck/Hutchinson, Nix/Gao/Huang and co-workers, were developed later in the mid - and late – nineties,

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and a large number of distinguished researchers (Fleck/Willis, Anand/Gurtin, Geers/Peerlings,

Estrin/Sluys,Voyiadjis, Polizzotto, Forest to mention a few) made seminal contributions in this area for interpreting

size effects and other phenomena at the micron scale.

 In the early and mid 1990’s – in collaboration with his experimental colleagues at Michigan Tech (Walter Milligan

and Steve Hackney) – he directed a project on nanostructured materials and “coined” the term “nanomechanics” as he

did earlier with “dislocation patterning” and “material instabilities”. They identified, theoretically and

experimentally, the critical grain size regime where plasticity transition occurs from grain rotation/sliding in the

absence of dislocation activity to intragranular avalanche-like dislocation motion. This mechanism has also been

numerically confirmed by molecular dynamics (MD) simulations later performed by Swygenhoven’s group at PSISwitzerland.

For bulk ultrafine and nanograin materials they discovered another plasticity transition mechanism

controlled by “multiple” or “massive” shear banding without any hardening, not observed for the conventional grain

size counterparts of these materials which are always strain-hardened. These micro/nanoplasticity mechanisms are

now routinely observed in nanocrystalline (NC) and ultrafine grain (UFG) materials produced by severe plastic

deformation (SPD), as well as in bulk metallic glasses (BMGs).

 Since 2000, while at Aristotle University of Thessaloniki, he continued with students and postdocs by employing his

earlier work on gradient elasticity and plasticity to address some key-unresolved issues in mechanics. They expanded

on dislocation and crack non-singular solutions (previously derived with his co-workers Altan, Gutkin, Ru et al) by

deriving new robust and easy-to-use expressions for the local microscopic stresses and strains on the basis of his

simple gradient elasticity (GradEla) model – a topic which has recently become popular in Greece (Vardoulakis,

Beskos, Exadaktylos, Georgiadis, Aravas, Giannakopoulos) and elsewhere (EU, US, China), since Mindlin’s original

but complex work which remained dormant for 30 years. Work also focused on dislocations/disclinations and

cracks/interfaces, as well as nanomaterials including nanotubes and nanomembranes. Gradient multi-element defect

kinetics were used to capture mechanical behavior at the nanoscale and obtain stability and defect patterning results

for thin films and small volumes. Wavelet analysis and neural networks were used for bridging the length scale

spectrum. Main senior collaborators in this area included A. Romanov / I. Ovid’ko (St. Petersburg, Russia) on defect

theory; A. Carpinteri / N. Pugno (Torino, Italy) on fractals and size effects; S. Forest (Ecole des Mines, France) and

P. Steinmann (Univ of Erlangen, Germany) on gradient plasticity; H. Askes (Univ of Sheffield) and M. Lazar (Tech

Univ of Darmstadt)/G. Maugin (Univ of Paris VI) on gradient elasticity; M. Zaiser (Univ of Edinburgh/Erlangen-

Nürnberg) on stochastic dynamics/avalanches and random plasticity; I. Groma (Eotvos Univ Hungary) on discrete

dislocation dynamics, and I. Vardoulakis (NTU-Athens, Greece) on soil mechanics and granular media.

 Since 2005, with his students and postdocs, he used variants of his earlier gradient elasticity and plasticity models to

interpret the deformation/fracture behavior and size effects observed during microtensile, microbending and

micro/nanoindentation tests. The results compared very well with corresponding molecular dynamics (MD) and

discrete dislocation dynamics (DDD) simulations for such micro/nano-objects (MEMS/NEMS, micro/nanobeams,

micro/nanoplates). They provided support of Nobel Laureate’s Richard Smalley (American Scientist 85, 324, 1997)

quotation “The Laws of Continuum Mechanics are amazingly robust for treating even intrinsically discrete objects

only a few atoms in diameter” by replacing “Continuum Mechanics” with “Gradient Continuum Mechanics”.

 Since 2008 his Lab activities were expanded to consider advanced energy materials/components, such as light

emitting diodes (with A. Romanov) and Li-ion batteries/LiBs (with K.E. Aifantis). This became possible through a

Marie-Curie Senior Fellowship (A. Romanov) on Nanomechanics of Defects in Solids with applications to thin films,

nanoparticles, nanocrystals and biomaterials and an ERC-Starting Grant (K.E. Aifantis) on Probing the Micro-Nano

Transition/MINATRAN, respectively. The major equipment that was purchased to conduct nanoindentation (NI) and

atomic force microscopy (AFM) studies for the above projects, was also used to initiate research on polymeric and

hydrophobic/hydrophilic materials for monument protection/cultural heritage preservation, as well as for novel

mechano-electro-chemical studies on neural cells.

 Since 2012 collaborations have been extended to include fractional derivatives and fractal media (jointly with V.

Tarasov at Moscow State University), zonal disintegration in deep underground tunnels (jointly with C. Qi at Beijing

University of Civil Engineering and Architecture) and, most recently, neuromechanics and medical imaging (jointly

with neurologists at AUT and Karolinska – work in progress).