What’s After Nanotechnology? Developing the Army’s Future Materials

Dr. David M. Stepp

U.S. Army Research Office

Materials Science Division

david.m.stepp@us.army.mil

(919) 549-4329, DSN 832-4329, FAX (919) 549-4399

http://www.aro.army.mil

2 March 2005

Today Objective Force

~100 lb. load

< 30 lb.effective

load

< 20 tons

> 40 mph

Innovation -- Accelerating the Pace of Army Transformation

70+ tons

0 mph

Fit the C-130 “Crucible”

The Hope for Army Transformation:Revolutionary Materials

Outline

• Basic Research Definition• U.S. Army Research Office Overview

– Types of Basic Research Awards– Major Focus Areas

• DoD Nanotechnology Definition• Nanotechnology and Lightweight Materials• What’s After Nanotechnology?

– Optimized Materials Design– Bio-hybrids– Improved Technology Transfer

Basic Research Defined(DoD 7000.14-R)

Basic research is systematic study directed toward greater knowledge or understanding of the fundamental aspects of phenomena and of observable facts without specific applications towards processes or products in mind.

It includes all scientific study and experimentation directed toward increasing fundamental knowledge and understanding in those fields of the physical, engineering, environmental and life sciences related to long-term national security needs.

It is farsighted high payoff research that provides the basis for technological progress. Basic research may lead to: (a) subsequent applied research and advanced technology developments in Defense-related technologies, and (b) new and improved military functional capabilities in areas such as…

Needs Driven Research

Lightweight Armor Materials

Ultra-lightweight Structures

Lightweight Power Sources

Combat ID/IFF

Opportunity Driven Research

Amorphous Metals

Computational Materials Science

Unique Characterization Tools

Microstructure Quantification

Foamed Materials

Self-healing Materials

Basic Research Refined

DirectorJim Chang

Operations

Faye Rodgers

Mathematical& Info Sciences

Mark Swinson

Legal CounselMark Rutter

AcquisitionCenter

Larry Travis

ResourceManagementGeorge Arthur

Mechanical Sciences

David Mann

ElectronicsWilliam Clark

Physical Sciences

Doug Kiserow (A)

Engineering Sciences

David Skatrud

PhysicsPeter Reynolds (A)

MaterialsScience

David Stepp

Chemical Sciences

Robert Shaw

LifeSciences

Mimi Strand

Computing &Info SciencesRandy Zachery

InformationManagementBessie Oakley

MathematicsDavid Arney

EnvironmentalSciences

Kurt Preston

OutreachPrograms

David Camps

InternationalPrograms

Jim Harvey/Sean Yu

Small BusinessPrograms

Susan Nichols

~ 100 employees at RTP 45 PhD Program Managers

~ 100 employees at RTP 45 PhD Program Managers

Chief ScientistHenry Everitt

U.S. Army Research Office(Research Triangle Park, NC)

ARO’s Broad Agency AnnouncementSingle Investigator Program (~$100k / year for 3 years)Conference / Symposium / Workshop Grants (~$5k for 12 months)Short Term Innovative Research, STIR (up to $50k for 9 months) Young Investigator Program, YIP (~$50k / year for 3 years)HBCU/MI Program (~100k / year for 3 years)

Multidisciplinary Research Program of the University Research Initiative, MURI(~$1M / year for 5 years)

DoD Experimental Program to Stimulate Competitive Research, DEPSCoR(>$350k for 3 years)

Defense University Research Instrumentation Program, DURIP(~$200k for 12 months)

Small Business Innovative Research, SBIR($70k for 6 months → $50k for 4 months → $730k for 24 months)

Small Business Technology Transfer, STTR (with “research institute” partner)($100k for 6 months → $750k for 24 months)

Externally Funded Programs

ARO Basic Research Awards http://www.aro.army.mil

Mechanical Behavior of Materials• High strain-rate phenomena

– Characterization tools– Deformation mechanisms– Lightweight damage tolerance

• Property-focused processing– Computational materials theory– Toughening mechanisms

• Tailored functionality– Active transport membranes– Self-assembling ceramics

Synthesis and Processing• Materials Processing

– Field activated/enhanced sintering– Powder consolidation

• Metastable materials and structures– Structural amorphous metals– Glass formability and transition– Ultra-fine grained materials

Physical Behavior of Materials• Heteroepitaxy

– Interface formation + diffusion– Strain mismatch– Engineering epitaxial layers

• Defect engineering– Semiconductors– Ferroelectrics

• Functional materials & integration– Electronics– Magnetics– Optics– Actuation

Materials Design• Growth and processing design

– Surface + interface engineering– Integrating dissimilar materials– Non-equilibrium processing– Modeling and simulation

• In-situ & nanoscale characterization– High resolution spectroscopy– Nondestructive characterization– Process control for

optimization

ARO Materials ScienceResearch Focus Areas

DoD Nanotechnology Defined

DoD nanotechnology programs are distinguished from those of other federal agencies in that the program activities are simultaneously focused on scientific and technical merit and on potential relevance to DoD. The overall technical objective of these programs is to develop understanding and control of matter at dimensions of approximately 1 to 100 nanometers, where the physical, chemical, and biological properties may differ in fundamental and valuable ways from those of individual atoms, molecules, or bulk matter. The overall objective for DoD relevance is to discover and exploit unique phenomena at these dimensions to enable novel applications enhancing war fighter and battle systems capabilities.

Richard P. Feynman (1918-88)

http://www.physics.umd.edu/robot/feynm/fphoto.htmlCourtesy AIP Niels Bohr Library

Nanotechnology andLightweight Materials

Motivating Nanotechnology(Richard P. Feynman, 1959)

• Is it possible to write (legibly) the entire 32 volumes of the Encyclopedia Britannica on the head of a pin? 600 pages each → 1.8M square inches

Circle 125 ft across → 25,000x pin head Resolving power of eye ≈ 1/120th inch

Demagnifying by 25,000x → 8nm

8nm dot contains ≈ 1000 atoms

“There’s plenty of room at the bottom”

How would you write it?

How would you read it?

How would you copy it?

How can this impact lightweight materials for defense?

http://www.greggman.com/japan/miraikan/miraikan.htm

} Dramatically increased feature density

Nanotechnology andLightweight Materials?

Strengths Unprecedented functional materials and functional structures

Feature densities (and surface areas)

Weight savings from reduced size of components “Inserting” function into proven structural materials

Degradation resistance, surface-area-based enhancements

Features can be engineered below critical defect size

Multifunctional materials Some enhancement from atomic-scale optimization, simulation

Most likely for highest-end applications (incremental)

Controlled electrodeposition for high quality metals (70 – 0 nm grain sizes)Molecular statics simulations to enhance understanding of deformationUnexpected behavior discovered – “nc” metals stronger in compression

Exploiting Nanoscale Structure(C. Schuh, MIT)

0 0.05 0.1

tension

compression

0 0.02 0.04 0.06 0.08

compression

tension

0

2

4

6

8

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Nickel, literature data

Ni-W alloys, current study

Har

dnes

s (G

Pa)

(Grain Size)-1/2

(nm)-1/2

100 25 11 6 4 3 2

Grain Size (nm)

Hall-Petch law

Wolfgang Pauli (1900-1958)http://www.geocities.com/ilian73/pauli.html

"This isn't right. This isn't even wrong."

Nanotechnology andLightweight Materials?

Weaknesses Excessive funding

Prolific “forced” nanotechnology focus in research proposals

Over-hyped and misleading results (esp. athletic equipment)

Relative improvements to substandard materials Non-falsifiable hypotheses Mechanical properties and extrapolating to design values

Micro/nano -scale testing does not correlate with bulk

Reliability and repeatability problematic

Material scale-up highly problematic Processing control, variations, and durability Nanotubes

Example: Actual Military Requests

“Injectable” training

Localized fluency in all languages; seamlessly blend into any cultural environment

Example: “Tactical neural nano-implant” Integrated self-protection capabilities

Indestructibility; appear to be standard regional dress

Example: “Carbon nanotube armor” Sensors and communications

Extend all senses; be able to detect stress or unusual behavior

Example: “Sensory enhancing nanobots” Shape shift materials

Ability to blend with any environment

Example: “Nano-fabrics that self heal, self clean, and adopt color and texture of surroundings”

Optimized Material Design Integrating Experimental and Computational Materials Science

Materials design theory links properties and microstructure to identify optimized microstructure (orange dot) and to predict the effects of

processing pathways (lines) on the physical properties of real starting materials (blue dots) [B. Adams, S. Kalidindi]

L0 = 4.51 cm V=998.7 m/s

0

100

200

300

400

500

600

0 2 4 6 8 10 12

Cop

per

Ste

el

Tita

nium

Alu

min

um

Win

dow

Gla

ss

Density

Str

en

gth

-to

-we

igh

t R

ati

o

AmorphousAlloys

Computational materials discovery enhanced development of leap-ahead anti-armor materials [W.L. Johnson]

Computational theory identified precise transport pathways in bacterial channels for the

development of revolutionary protective membranes [T.L. Beck]

Materials theory motivated discovery of unprecedented thermoelectric materials with ultra-fine structure for advanced

thermal management [M. Dresselhaus, Hicks]

Well or Wire Width (Ǻ)

Fig

ure

of

Mer

it (

ZT

)

Integrated computational models, experimental characterization tools and materials processing efforts guide advanced fiber and fabric designs for unparalleled armor systems [P.M. Cunniff]

40 nm

200 nm

woodpile structure

Brillouin zonephotonic band gap

Computationally-guided structure Direct writing of polyelectrolyte ink

step 1

Robotically defined woodpile structure

step 2a) SiO2 CVD (25°C)b) Calcine (475°C)

5 µm

2 µm

step 3

Si CVD(475°C)

SiO2 replica of polymer woodpile

Si woodpile structure

step 4

Spectroscopy and modeling

underway, future iterations of

structure and processing for

complete photonic band gap material

3D MURI(U. Illinois U-C, Stanford, U. New Mexico)

Large-Strain Magnetic SMAs(I. Karaman, Texas A&M University)

5

4

3

2

1

0

Str

ain,

%

200150100500Temperature,°C

125 MPa

100 MPa

75 MPa

50 Mpa

CoNiAl Compression<100> orientation, Water Quenched

50 MPa 75 MPa 100 MPa 125 MPa

Strain vs. temperature response of a CoNiAl alloy showing >4% shape memory

strain and hysteresis shrinkage

5

4

3

2

1

0

Str

ain,

%

-15x103

-10 -5 0 5 10 15Magnetic Field,G

2 MPa 3 MPa 4 MPa 5 MPa 6 MPa

Ni2MnGa

Strain vs. magnetic field response of Ni2MnGa demonstrating very large

magnetic field induced strain (more than 4.5% in compression)

Simulations predicted extraordinary potential for large force, large strain, and high frequency actuator materials

Induced strains demonstrated up to 4.2% under compression, 10% in tension

Nanoporous Energy Absorbing Systems(Y. Qiao, U. Akron)

Hydrophobic Nanoporous particle

Container Piston

Nanopore

Surface of the nanoporous silica particle

Water

D

2r

p

p

Gasket

v

When a non-wetting liquid is forced to flow into nanoporous materials under external pressure, due to the high surface/mass ratio a large amount of energy will be transformed into the solid-liquid interfacial tension

Modeling predicted the energy absorption efficiency of nanoporous systems will be higher than larger systems by an order of magnitude

Water

NEAS

Time (sec)

Str

ain

(%)

Dynamic Testing Results (SHPB)

6-20 nm pore size, 10-12% coverage, ~12 J/g energy absorption

Bio-Hybrids Integrating Functional, Structural and Biological Materials

E-field switchable

specificbinding to

surface

Controlled binding

Reconfigurable self-assembly and regeneration

Spatially directed growth of quantum dots and nanoscale coatings

Targeted and controlled drug delivery

A genetically driven and universal process for controllable and switchable adhesive materials interfaces

OBJECTIVE:

To produce synthetic flexible membranes containing biological transport proteins that can utilize energy for the selective uptake, concentration and release of ions and molecules in an organized manner. The effort includes production of both macroscopic membranes and nanostructures containing transport proteins with vectorial transport function.

ACCOMPLISHMENTS:• The first ever functional ion-selective synthetic

protein membrane on inorganic support has been prepared and demonstrated, providing unprecedented potential for future sensors, drug delivery, and fuel cells.

• Developed enhanced algorithm to predict transport pathways in proteins, even for very large turns; this effort identified 4 possible pathways within the bacterial Cl channel that were later confirmed by experimental evidence.

RESEARCH TEAM:

University of CincinnatiJohn Cuppoletti (Physiology and Biophysics)T.L. Beck (Computational+Theoretical Chem.)J. Boerio (Materials Science and Engineering)J.Y.S. Lin (Chemical Engineering)P.R. Rosevear (Biochemistry and Microbiology)

University of PittsburghR. Coalson (Computational Chemistry+Physics)

Synthetic Active Transport MURI(U. Cincinnati & U. Pittsburgh)

Self-Healing F-R Composites(M. Kessler, University of Tulsa)

Technical Objective: To demonstrate and refine robust self-healing fiber-reinforced composite materials for recovery of micro-cracking and similar small-scale damage.

Self healing conceptSEM micrograph showing fracture surface of

a healed reference plain weave specimen

Nanomanufacturing to enable scaled-up, reliable, cost effective manufacturing of nanoscale materials, structures, devices, and systems; the development and integration of ultra-miniaturized top-down processes and increasingly complex bottom-up or self-assembly processes.

Small Business Innovative Research (SBIR) Small Business Technology Transfer (STTR) Manufacturing Technology (MANTECH) program

Industry partnerships? Spiral development? “Preliminary” field testing?

Improving Technology Transfer

david.m.stepp@us.army.milhttp://www.aro.army.mil

• Basic Research and the U.S. Army Research Office– Farsighted high-payoff research– Needs driven and opportunity driven basic research efforts

• Nanotechnology and Lightweight Materials– Tremendous potential for enhancing functionality– Beware non-falsifiable hypotheses, esp. for mechanical/structural apps.

• What’s After Nanotechnology– Optimized Materials Design?– Bio-hybrids?– Improved Technology Transfer