Research in Mechanics and Nano S&Eby

Ken P. ChongPhD, PE

Director of Mechanics & MaterialsEngineering Directorate

National Science Foundation

www.nsf.gov

National Science FoundationFY2005 Request – ($5.7B) and ’05 Increases

National Science Board

Director

Office of theInspector General

Staff Offices

Directorate forEngineering

Directorate forBiologicalSciences

Directorate forGeosciences

Directorate forComputer and

InformationScience andEngineering

Directorate forMathematicaland Physical

Sciences

Directorate forSocial,

Behavioral,and Economic

Sciences

Directorate forEducation and

HumanResources

($13.0M) $600M ($13.4M) $618M ($-167.6M) $771M

($10.3M) $472M ($15.4M) $729M ($24.0M) $1,116M ($20.9M) $225M

Polar and Antarctic Programs

($7.6) $350M

IntegrativeActivities

(MRI, STC)

($95.9) $240M

SBIR/STTR

($0.5M) $104M

NSF Engineering DirectorateFY2005 Request

Assistant Director John A. Brighton

Deputy Assistant DirectorMichael Reischman

Design,Manufacture &

Industrial InnovationDMII

Civil &Mechanical

SystemsCMS

Electrical &Communications

SystemsECS

EngineeringEducation &

CentersEEC

Bioengineering & Environmental

SystemsBES

Vasu Varadan Gary Gabriele Warren DeVries

Bruce Hamilton Ken Chong* Richard Buckius

Senior Advisor

SBIR/STTR**

Mike Roco

($10.3M) $471.8M

SBIR/STTR**

($-1.3M) $49.8M ($18.3M) $85.5M ($0.5M) $68.9M)

Chemical &TransportSystems

CTS

Chemical &TransportSystems

CTS($-1.7M) $67.2M

($-1.9M) $72.7M($0.1M) $65.9M ($-3.3M) $130.7M($0.5M) $104.1M

Kesh Narayanan

**NSF-wide program – now changed to Office of Industrial Innovation; * now Adnan Akay

NanotechnologyDefinition on

www.nano.gov/omb_nifty50.htm (2000)

Working at the atomic, molecular and supramolecular levels, in the length scale of approximately 1 – 100 nm range, in order to understand, create and use materials, devices and systems with fundamentally new properties and functions because of their small structure

NNI definition encourages new contributions that were not possible before.- novel phenomena, properties and functions at nanoscale, which are nonscalable outside of the nm domain - the ability to measure / control / manipulate matter at the nanoscale in order to change those properties and functions- integration along length scales, and fields of application

NNI FY 2006 Budget RequestTotal = $1,054 million

Infrastructure Outcomes of 2001-2005: NSF R&D Networks and User Facilities

• Network for Computational Nanotechnology (NCN)7 universities (Purdue as the central node) Nanoelectronic device simulation/modeling

• National Nanotechnology Infrastructure Network (NNIN) 13 universities with user facility Development measuring & manufacturing tools, including NEPM Education and societal implications

• Oklahoma Nano Net (EPSCoR award)

Centers: 16 Nanoscale Science and Engineering (NSEC) - 6 (2001); 2 (2003); 6 (2004); 2 (2005)1 Nanotechnology Center for Learning and Teaching (NCLT)6 new Materials Research Science and Engineering Centers (MRSEC)

Areas of investment in FY2006(Program Component Areas)

1. Fundamental Nanoscale Phenomena and Processes

2. Nanomaterials3. Nanoscale Devices and Systems4. Instrumentation Research, Metrology, and

Standards for Nanotechnology5. Nanomanufacturing6. Major Research Facilities and Instrumentation

Acquisition7. Societal Dimensions

TINSELY ODEN, CHAIR; UT-AUSTIN

POC: KEN P. CHONG, NSF

PreliminariesPurpose of the BRP:

To explore the emerging discipline of Simulation-Based Engineering Science, its major components, its importance to the nation, thechallenges and barriers to its advancement, and to recommend to the NSF and the broader community concerned with science and engineering in the United States, steps that could be taken to advance development in this discipline.

Blue Ribbon Panel:J. Tinsley Oden (Chair) - UT Austin Ted Belytschko - Northwestern

Jacob Fish - Rensselaer Polytechnic Institute Thomas J.R. Hughes - UT Austin

Chris Johnson – University of Utah David Keyes – Columbia University

Alan Laub - UCLA Linda Petzold - UCSB

David Srolovitz - Princeton Sidney Yip - MIT

MSMBBB

HomelandSecurity

HP mat’ls/devices

V&V and UQ

Mod.& Simu.

@Nanoscale

Energy&Env.

SBE

SDDDAS

Multi-Phenomena-physics-scale Systems

CRCNS

Global

Enterpr

ises

Healthcare

Mfg. Supply Chain&Transp

Simulation Software

Next Generation AlgorithmsBig

Data Visuali

zatio

n

HPC

, CI

Modern Computation

Applied Math

Engineering Sciences

Computer Science

Others

Overarching Framework for Multiscale Modeling:

atomistic → micro → meso → macro

Key: interfaces between models at different scales

Questions:

• What are the information that needs to be transferred from one model to another?

• What are the correct ways to achieve such transfer of information?

• What physical principles must be satisfied during the transfer of information or simulation results?

Need: A set of logic, mathematical, and physical rules to govern information transfer across the interfaces

JIMMY HSIA, NSF

CORE ISSUES: Challenges, Barriers and Opportunities

• Tyranny of Scales

• Verification, Validation, and Uncertainty Quantification

• Dynamic Data Driven Simulation Systems

• Sensors, Measurements, and Heterogeneous Systems

• New Vistas in Simulation Software

• Big Data and Visualization

• Next Generation Algorithms

Materials andSurface Engineering

Solid and Bio Mechanics

Nano- and Micro Mechanics

Contact mechanics, biomimeticmaterials, thin film mechanics

Nanotribology, ultra thin film behavior, AFM mechanics, nano-structured surfaces

MEMS reliability, strength,lubrication; nano-biomechanics

Multiscale modeling

Cutting edge activities are at the interfaces

Mechanics and Materials

Adv. Solid Mechanics

Micro-Mechanics

Meso-Mechanics

Macro-Mechanics

Multi-scaleMechanics

Constitutiverelations

Experimental methods

Numericalmethods

Damage mechanics

AdvancedSimulation

Temporal, spatial

Damagemechanics

Advanced Composites

Thermal stresses

Durability,performance

Simulation,modeling

Defects

Micro-Structure

Fracture,fatigue

Deformation

Theoreticalmethods

Numerical, Exptal, analytical

Interfacialmechanics

Constitutive models

Structuralstates

Simulation,modeling

Transformation, evolution

Numerical, Exptal, analytical

Multi-phenonmena

Multi-physics

Thermal, env.forces

Simulation,optimization

Numerical,

Exptal, analytical

Electronicmaterials

Wet/dry; smartmaterials

Self-healing,Self-cleaning

Adv. Composites,Bio-inspired

Durability,performance

Simulation,optimization

Analytical,theoretical

EngineeringMaterials

Numerical, Exptal, analytical

Frontiers in solid mechanics and engineering materials

Grand Challenges & The Great Payoff: Applications and Benefits of SBES

• Medicine• Homeland Security• Energy and Environment• Materials• Industrial Applications• …

NSF Press Release 06-049Supercomputer Maps One Million Atoms of a Complete Virus in

First Simulation of a Life FormVirtual virus takes 100 days on supercomputer, 35 years on a desktop

for 50ns

Credit: University of Illinois at Urbana-Champaign's Theoretical and Computational Biophysics Group.

Composites of Carbon Composites of Carbon NanotubesNanotubes (CNT)(CNT)

10

100

1000

1 10 1000.1

SpecificModulusGPa/(g/c3)

Specific Strength, GPa/(g/c3)0.2 0.5 2 5 20 50

20

50

200

500

Aluminum 2219

Baseline Material,available today

Best availableunder development

CFRP Composite

CNTFRP Composite

Single Crystalbulk material (CNT)

Emerging material, carbon nanotubes

Long-term potentialof CNT material

from NASA-larc

Predicted Weight Savings from Polymer Matrix Composites(Primary Structure and Cryogenic Fuel Tanks)

Systems Analysis Results for a Reusable Launch Vehicle (RLV)

VehicleDryWeight

1.0

Aluminum CFRPComposite

CNTFRPComposite

from NASA-larc

55 % reduction

82% reduction

EDUCATION

• 10-12 m QUANTUM MECHANICS [TB, DFT, HF…]

• 10-9 MOLECULAR DYN. [LJ…]; NANOMECHANICS;MOLECULAR BIOLOGY; BIOPHYSICS

• 10-6 ELASTICITY; PLASTICITY; DISLOCATION...

• 10-3 MECHANICS OF MATERIALS

• 10-0 STRUCTURAL ANALYSISMULTI-SCALE, MULTI-PHENOMENA ANALYSES & SIMULATIONS…____________________________________________________________TB = TIGHT BINDING METHOD; DFT = DENSITY FTNAL THEORY;HF = HATREE-FOCK APPROX.; LJ = LENNARD JONES POTENTIAL

• NSF SUMMER INSTITUTE OF NANOMECHANICS & MAT’LS, NORTHWESTERN UNIVERSITY –contact: PROF. W.K. LIU

Scales in Plasticity

discrete dislocation models classical plasticity theories

size effects: 0.1 µm – 0.1 mm

10nm 0.1µm 1µm 10µm 0.1mm 1mm

Dislocation-based plasticity theories ?

• Any continuum plasticity theories apply only above 0.1µm !

less than 0.1µm individual dislocations ⇒ plasticity

( analogy: less than 1nm individual atoms ⇒ elasticity )

Y. HUANG, UIUC

Size Effect in PlasticityTorsion of thin wires

Fleck et al., 1993

Bend of thin beams

Soboyejo et al., 2003

Al matrix with SiC particles Vf = 15%; Particle diameter:

d = 16µm and 7.5µm

Smaller is harder!

Nano-mechanics

---- A continuum theory based on the A continuum theory based on the interatomicinteratomic potentialpotential

Interatomic Potential(nonlinear, multi-body springs)

representative material point

continuum m

odeldiscre

te sy

stem

keep

ing tr

ack o

f eve

ry at

om

Molecular Dynamics Atomistic-based Continuum Theory

Y. HUANG, UIUC

Principle of AFM

SEM image of the AFM cantilever and tip.

http://www.di.com/app_notes/spmtechnology_appnotes.htm

MEASURE FORCE F = F(d)

GERDBINNIG1986 NOBELPRIZE [STM]

CHALLENGES

multi-scale

LDLM Large Deformation Laser MoireFGLM Fine Grating Laser MoireLSI Laser Speckle InterferometryDIC Digital Image Correlation

HRTEM High Resolution Transmission Electron MicroscopyCFTM Computational Fourier Transform MoireAFM Atomic Force MicroscopySEM Scanning Electron MicroscopySRES Surface Roughness Evolution Spectroscopy

Map of Deformation-Measurement Techniques

Interface Energy Limit

Interferometric Gain

of Resolution

HRTEM-CFTM

LDLM

DIC

SRES

FGLM & LSI

Field Projection Method

Equilibrium Smoothing

Field of View (Gage Length in )mSt

rain

Res

olut

ion

10 -1

10 -9

10 -8

10 -7

10 -6

10 -5

10 -4

10 -3

10 -2

10 -1

10 -2

10 -3

10 -4

10 -5

10 -6

AFM Interferometry

NSF Award No. CMS-0070057, Engineering Directorate (Program Manager: Dr. K.P. Chong & Jorn Larsen-Basse)

K.-S. Kim, Nano & Micromechanics Laboratory, Brown University

L. SUNG, NIST

BORESI AND CHONG, ELASTICITY IN ENGINEERING MECHANICS, WILEY, 2000.

NASA Langley Research CenterNanotechnology Modeling and Simulation

Qualitative Predictions Quantitative PredictionsStructuralMechanics

Molecular Assembly

Computational Materials

Computational Chemistry

Computational Mechanics

• Electrons• Nuclei• Atoms

• Molecular fragments• Bond angles• Force Fields

• Surface Interactions• Orientation• Crystal Packing• Molecular Weight• Free Volume

• Constituents• Interphase• Damage

Fiber

Matrix

Length, (m)

10-12 10-9 10-6 10-3 100

Nano MesoQuantum Micro Macro

C

C

C

CO

CO

CO

CO2

CO2

CO2

CO

WhyMultiple Temporal Scales?

Induced by Multiple

Spatial Scales

Global Scale

Component Scales Material Scales

Multiple temporal scales Single Physical Process Induced by Multiple

Physical Processes

J. FISH, RPI

Multiple Temporal Scales for Fatigue• Multiple time scales:

• Two-scale model:0; =r

ttττ ζ

ζ=

( ) ( ) , ,1, , , ; tt tζ ζ

τφ φ τ φ φ φζ

= = +x x

:ζ scaling parameter determined by load frequency and material parameters

:ζφ

0 :τ characteristic length of micro-chronological time:rt characteristic length of macro-chronological time

response fields (e.g., displacement, stress, strain, etc…)

J. FISH, RPIJ. FISH, RPI

MultiMulti--Scale MultiScale Multi--Phenomena Modeling of Phenomena Modeling of

Structure / Property / Structure / Property / FunctionFunction

10 µm

Multi-Scale Composite

Epoxy Matrix

Nanocomposite1 µm

CarbonFiber

Nanocomposite

Carb

on

Fibe

r

100 nmCarbon Nanotubes

1 nmZig-ZagArmchairAtomic Interactionsr0

Stretching 0θ

Bending

Torsionvan der Waals

1 ÅModelin

g Hierarchy – Bridging th

e Scale from Nano to

Macro

T.W. CHOU, U. DEL.

RAJIV KALIA, LSU

S:

q=scattering wave vector

RAJIV KALIA, LSU

DISCUSSIONS OF COMMON MODELING METHODS

• FIRST PRINCIPLE CALCULATIONS - TO SOLVE SCHRODINGER’S EQ. AB INITIO, e.g. HATREE- FOCK APPROX., DENSITY FUNCTIONAL THEORY,… - COMPUTIONAL INTENSIVE, O(N4)- UP TO ~ 3000 ATOMS

• MOLECULAR DYNAMICS [MD] - DETERMINISTIC, e.g. W/ LENNARD JONES POTENTIAL- MILLIONS TIMESTEPS OF INTEGRATION; TEDIOUS- UP TO ~ BILLION ATOMS FOR NANO-SECONDS

• COMBINED MD & CONTINUUM MECHANICS [CM], e.g. MAAD; LSU; BRIDGING SCALE; …- PROMISING...

Bio-inspired Mechanics and Materials

Hierarchical Structure of Human Bone• Macrostructure

– Trabecular bone– Cortical bone

• Microstructure (10 – 500 µm)– Single osteons (cortical bone)– Trabeculae (trabecular bone)

• Sub-microstructure (1 – 10 µm)– Lamellae

• Nanostructure (below 1 µm)– Collagen fibrils– Hydroxyapatite (HA) crystals– Crystal-Collagen structure

http://silver.n

I. Jasiuk, GA Tech

The Mechanical Performance of Nacre from Seashells The Mechanical Performance of Nacre from Seashells ––Superior Toughness through Microstructural DesignSuperior Toughness through Microstructural Design

H.D. Espinosa

National Science Foundation Award No. CMS-0301416 Ken Chong

MotivationsMotivations

(Wegst & Ashby 2004)

Geological Aragonite: Geological Aragonite: A brittle ceramic A brittle ceramic KKICIC=0.3 MPa.m=0.3 MPa.m1/21/2

Nacre (95 % aragonite): Nacre (95 % aragonite): A tough bioA tough bio--compositecomposite

KKICIC=8=8--10 MPa.m10 MPa.m1/21/2

• Nacre is 20-30 times tougher than aragonite

• How does the microstructure make nacre tough?

• This is still unclear (see G. Mayer in Science, 2005) but it is much sought after, because it may open the way to synthetic mimics of nacre with superior properties (biomimetics)

The microstructure of nacre

Gecko: nano-scale attachment (K. Autumn et al. 2002)

G. Huber

Mechanics of a Mosquito Bite-Design of a Bio-mimetic

Painless Needle(Supported by NSF Grant Number CMS

0402857)M. K. Ramasubramanian, PI

J.F. Tu, Co-PICharles Apperson (Entomology)

Mosquito Skin Penetration Mechanics

• Non-conservative force application for significant increase in bucking load (Beck’s Column).

• Labium provide lateral support and keep the fascicle moist and lubricated.

• The head oscillates between .5 to 5 Hz horizontally, maintaining the force application direction tangential to the fascicle, and prevent buckling.

• Increase in buckling load is sufficient for skin penetration.

What’s special about spider silk?

Material Strength Elasticity Energy to Break(N m-2) (%) (J kg-1)

Dragline Silk 4 x 109 35 1 x 105

Minor Silk 1 x 109 5 3 x 104

Flagelliform silk 1 x 109 200+ 1 x 105

KEVLAR 4 x 109 5 3 x 104

Rubber 1 x 109 600 8 x 104

Tendon 1 x 109 5 5 x 103

______________________________________________________________________TABLE 1. Various biological and manmade materials are listed with their strengths, elasticities, and energies to break. Note the over ten-fold increase in the energy to break of dragline silk compared to KEVLAR. This dramatic increase is due to the elasticity of dragline silk. Also note the differences in elasticity among dragline, flagelliform and minor ampullate silks.

Randy Lewis, et al

Defining the vision and implementation planDefining the vision and implementation plan

National Nanotechnology InitiativeNational Nanotechnology Initiative

ReportsReports

Planning with feedback after each: 5 years, 1 year, 1 month; and various levels: national/NSET, agency, program In preparation: Topical reports; new 2004:10 year vision

1999: 10-year vision

MC. Roco, 10/09/03

Worldwidebenchmark

Brochure forpublic

Societalimplications

Govtplan

Defining the vision for the second strategic plan (II)Defining the vision for the second strategic plan (II)

National Nanotechnology InitiativeNational Nanotechnology Initiative20042004

ReportsReports

2004: 10-year

vision/plan Agricultureand Food Societal

Implications2004

GovernmentPlan (annual)

Energy

Surveymanufacturing Other topical reports

on www.nano.gov 2004: Update 10 year vision, and develop strategic plan

MC Roco, 3/16/05

www.nsf.gov

chaired by J. Tinsley Oden, 2006 report on “Simulation-Based Engineering Science”: www.ices.utexas.edu/events/SBES_Final_Report.pdf. www.nsf.gov/publications/pub_summ.jsp?ods_key=sbes0506

Chong, K. P., “Research and Challenges in Nanomechanics” 90-minute Nanotechnology Webcast, ASME, Oct. 2002; archived in www.asme.org/nanowebcast

Boresi, A. P., and Chong, K. P., Elasticity in Engineering Mechanics, John Wiley, 2000

Boresi, A. P., Chong, K. P., & Saigal, S. Approximate

Solution Methods in Engineering Mechanics, Wiley, 2003.

Chong, K. P., “ Nanoscience and Engineering in Mechanics and Materials”, J. of Physics & Chemistry of Solids, 65(2004) 1501-1506, Elsevier. [No. 1 of ScienceDirect TOP25 Hottest Articles]

NSF SUMMER INSTITUTE ON NANO MECHANICS & MATERIALShttp://tam.northwestern.edu/summerinstitute/Home.htm

SUMMARY & DISCLAIMER An overview of major advances, challenges and research concerning mechanics and materials are presented. The author would like to thank his colleagues and many members of the research communities for their comments and input during the writing of this presentation.

Information on NSF initiatives, announcements and awards can be found in the NSF website: www.nsf.gov. The opinions expressed in this article are the author’s only, not necessarily those of the National Science Foundation [NSF]. Any commercial products identified are for illustrations only, do not imply any endorsement.