1. Lee, Les - Mechanics of

8/7/2019 1. Lee, Les - Mechanics of

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MECHANICS OF

MULTIFUNCTIONALMATERIALS & MICROSYSTEMS

B. L. (Les) LeeProgram Manager

AFOSR/NAAir Force Research Laboratory

AFOSR

18 March 2011

Distribution A: Approved for Public Release. Distribution is unlimited. 88ABW-2011-0793


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NAME: B. L. LeeBRIEF DESCRIPTION OF PORTFOLIO:Basic research forintegrationofadvanced materialsandmicro-systemsinto future Air Force systems requiringmulti-functionality

LIST OF SUB-AREAS:Life Prediction (Materials & Devices);Sensing & Diagnosis;Micro-, Nano- & Multi-scale Mechanics;Multifunctional Design (Shape Change);Multifunctional Design (Property Tuning);Self-Healing & Remediation;Self-Cooling & Thermal Management;Self-Sustaining Systems & Energy Management;Precognition & Neutralization of Threats;Engineered Nanomaterials

2011 AFOSR SPRING REVIEW2302B PORTFOLIO OVERVIEW


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Multifunctional Design

The objective of multifunctionality is improvement in system performance Use system metric(s) to identify functions to combine and quantify gains.

General Rules:

Add functionality to material with most complex function-physics.

Target unifunctional materials/components operating in the mid-to-lowerfunctional performance regimes for multifunctional replacement.

Implement multifunctionality in the conceptual stage of system design.

Performance of multifunctional material/component may not be as good as itsunifunctional counterpart; irrelevant as long as system performance improves.

Strong/weak coupling between the multiple function-physics may or may notexist and/or be important.

Multifunctional potential depends on sub-system interfacing capabilities andfunction compatibility.

RESEARCH ISSUESGuest Lecture by Dr. J. Thomas - 2008 AFOSR M^4 Program Review


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RF-on-Flex

Conformal Load Bearing Arrays

SENSOR PLATFORMSSource: AFRL/RB

Integrate antennafunction into the

structureAntenna structure isload bearing

LO enabling

Reduced maintenance

vulnerability


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VISION: EXPANDED

site specific

autonomic

AUTONOMICAEROSPACE

STRUCTURES Sensing & Precognition

Self-Diagnosis & Actuation

Self-Healing

Threat Neutralization

Self-Cooling

Self-Powered

Biomimetics

Design for CoupledMulti-functionality

Nano-materials

Multi-scaleModel

Micro- & Nano-

Devices

Manufacturing Sci

Neural Network &Information Sci


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VISION: EXPANDED

site specific

autonomic

AUTONOMICAEROSPACE

STRUCTURES

Sensing & Precognition


Self-Healing

Threat Neutralization

Self-Cooling

Self-Powered

Biomimetics


Nano-materials

Multi-scale

Model

Micro- & Nano-Devices

Manufacturing Sci


11

FUNCTIONS OF INTEREST

Active Regulation

Reactive Materials

Mesoporous Networks

Adaptive Fluids/Solids

Self-Regulating

FunctionSelf-Generating

Function

BIO-INSPIRED SYSTEMS:BEYOND CURRENT VISION


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VISION: EXPANDED

site specific

autonomic

AUTONOMICAEROSPACE



Self-Healing

Threat Neutralization Self-Cooling

Self-Powered

Biomimetics


Nano-materials

Multi-scaleModel

Micro- & Nano-

Devices

Manufacturing Sci


ReconfigurableSystems


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VISION: EXPANDED

site specific

autonomic

AUTONOMICAEROSPACE



Self-Healing


Self-Powered

Biomimetics


Nano-materials

Multi-scaleModel

Micro- & Nano-

Devices

Manufacturing Sci


Energy fromAerospace

Environ


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PROGRAM INTERACTION

AFOSRStructural MechanicsStructural MaterialsOrganic Chemistry

Biosciences

MicroelectronicsOTHERS

AFRL/RVSpace System

AFRL/RYUAV Antennas

AFRL/RWMicrosystems

AFRL/RXComposites (2)Multiscale Anal

AFOSR MURI 05

Self-Healing

AFOSR MURI 06

Energy Harvesting

EXTRAMURALUNIVERSITIES

INDUSTRY

MECHANICS OFMULTIFUNCTIONAL

MATERIALS &MICROSYSTEMS

AFRL/RBEnergy Mgt

Fund Flow

ArmyNavy

DARPA

GameChanger 07Antenna Integration

Discovery CT 09Reconfigurable

AFOSR MURI 09

Sensing Network

Directors Call 09Energy from Environ

NSFESF

NASA


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NAME: B. L. LeeBRIEF DESCRIPTION OF PORTFOLIO:Basic research forintegrationofadvanced materialsandmicro-systemsinto future Air Force systems requiringmulti-functionality

LIST OF SUB-AREAS:Life Prediction (Materials & Devices);Sensing & Diagnosis;Micro-, Nano- & Multi-scale Mechanics;Multifunctional Design (Shape Change);Multifunctional Design (Property Tuning);

Self-Healing & Remediation;Self-Cooling & Thermal Management;Self-Sustaining Systems & Energy Management;Precognition & Neutralization of Threats;Engineered Nanomaterials

2011 AFOSR SPRING REVIEW2302B PORTFOLIO OVERVIEW


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NAME: B. L. LeeBRIEF DESCRIPTION OF PORTFOLIO:Basic research for integration of advanced materials and micro-systems into future Air Force systems requiring multi-functionality

LIST OF SUB-AREAS:Life Prediction (Materials & Devices);Sensing & Diagnosis;Micro-, Nano- & Multi-scale Mechanics;Multifunctional Design (Shape Change);Multifunctional Design (Property Tuning);


PROGRAM TRENDS


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SCIENTIFIC CHALLENGES &PROGRAM ACHIEVEMENT

Self-healable or in-situ remendable structural materials(1st-everprogram; world lead)

Microvascular composites for continuous self-healingand self-cooling systems (1st-everprogram; world lead)

Structural integration of energy harvest/storagecapabilities (1st-everprogram on structurally integrated multipleenergy harvest capabilities; DoD lead)

Neurological system-inspired sensing/diagnosis/

actuation network (potlworld lead) Mechanized material systems and micro-devices for

reconfigurable structures (DoD lead)

Experimental nano-mechanics (DoD lead)


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Transformational Opportunities

Self-healable or in-situ remendable structural materials Quantum improvement in survivability of aerospace structures*

Microvascular composites for continuous self-healingand self-cooling systems * & Ultimate thermal management

Structural integration of energy harvest/storagecapabilities Self-sustaining UAV and hybrid-powered aircraft

Neurological system-inspired sensing/diagnosis/actuation network Autonomic state awareness in aerospace

Mechanized material systems and micro-devices forreconfigurable structures Morphing wing aircraft

Experimental nano-mechanics Experimental verification ofmulti-scale analysis


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Other Organizations That FundRelated Work

Self-healable or in-situ remendable structural materials ARO (co-funding on thermal remediation; coord with MURI onself-healing chemistry); NSF; industry

Microvascular composites for continuous self-healing

and self-cooling systems NSF (manufacturing process) Structural integration of energy harvest/storage

capabilities AFOSR/ARO/AFRL/ARL/NRL (DoD Task Force)

Neurological system-inspired sensing/diagnosis/

actuation network NSF/ESF (joint workshop, initiative coord) Mechanized material systems and micro-devices for

reconfigurable structures AFRL/RX,RB,RW (joint lab task)

Experimental nano-mechanics ARO (high-rate); Sandia


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PROGRAM COLLABORATION

THE 1ST

MULTIFUNCTIONALMATERIALS FOR DEFENSE

WORKSHOP

Theme 10: Power and Energy

In conjunction with:The 2010 Annual Grantees/Contractors Meeting for

AFOSR Program on

Mechanics of Multifunctional Materials & Microsystems(M^4)

13-14 May 2010Hyatt Regency Reston, Reston, VA

Workshop Co-Chairs:James Thomas (NRL)

Eric Wetzel (ARL/WMRD)William Baron (AFRL/RBSA)

Organizing Committee:B.-L. (Les) Lee (AFOSR), Co-Chair

Bruce LaMattina (ARO), Co-ChairWilliam Baron (AFRL/RBSA)Gregory Reich (AFRL/RBSA)

William Nothwang (ARL/SEDD)Daniel OBrien (ARL/WMRD)

Eric Wetzel (ARL/WMRD)James Thomas (NRL)

Agent for 8 Projects; Concluded

BAA 06-028:

FY07 ARO MURI Topic #24Self-healing Polymer Composites through

Mechanochemical TransductionGrant PI: Jeff Moore (UIUC)

PM: David Stepp (ARO)

Co-PM: Douglas Kiserow (ARO)

WORKSHOP:2006/01/05, Chapel Hill, NC

KICK-OFF:2007/10/03, Aberdeen, MD

BioSensing and BioActuationProposed Research Opportunities/Challenges

1. Hierarchical Organization of Biological SystemsUncover the unifying aspects underlying hierarchical bio-structures and bio-systems and usethem for sensing and actuation; apply to new multi-scale and multi-functional sensor/actuatorconcepts.

2. Sensor Informatics Guided by LifeCreate new knowledge that will be exploited in novel bio-inspired data mining and dynamiccontrol, including capabilities to monitor, assess, and control living and engineered systems in

sensor-rich environments.3. Multifunctional Materials and Devices for Distributed

Actuation and SensingUnderstand biological systems and mechanisms that lead to their ability to exhibit fault-tolerant

actuation with a wide dynamic range, the production of practical means for producing artificialstructures that exhibit similar behaviors, and their incorporation into useful engineered systems.

4. Forward Engineering & Design of Biological/BiomedicalComponents & SystemsSynthesize hybrid synthetic-living systems through systems-level integration of biological andengineered components that sense, actuate, compute, regenerate and efficiently allocateresources in order to achieve desired responses and functions.


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VISION: EXPANDED

site specific

autonomic

AUTONOMICAEROSPACE



Self-Healing


Self-Powered

Biomimetics


Nano-materials

Multi-scaleModel

Micro- & Nano-

Devices

Manufacturing Sci




Environ


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VISION: EXPANDED

site specific

autonomic

AUTONOMICAEROSPACE



Self-Healing


Self-Powered

Biomimetics


Nano-materials

Multi-scaleModel

Micro- & Nano-

Devices

Manufacturing Sci


PIs & Co-PIs:

Scott White(UIUC)Jeffrey Moore(UIUC)Nancy Sottos(UIUC)Sia Nemat-Nasser(UC San Diego)Markus Buehler(MIT)Scott White(UIUC)*Jeffrey Moore(UIUC)*

Nancy Sottos(UIUC)*Jennifer Lewis(UIUC)*Philippe Geubelle(UIUC)*Kenneth Christensen(UIUC)*Jonathan Freund(UIUC)*Chris Mangun(CU Aero)Tom Darlington(Nanocomposix)

Tony Starr(SensorMetrix)Tom Hahn(UCLA)

^ YIP; * MURI

THREE APPROACHES


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THREE APPROACHESFOR SELF-HEALING

MICRO & NANOCAPSULES


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SEM of 20wt% functionalized capsules in Epoxy (EPON 828/DETA)

10 um

Shell wall

1 m

100 nm

Microtome Epoxy

(3-glycidoxypropyl)trimethoxysilane(GLYMO) to limit aggregation andimprove dispersion

SiO2

PUF

Core09: MICRO & NANOCAPSULESFOR SELF-HEALING (UIUC: Sottos)


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All fibers coated by dip-coat method All concentrations determined by TGA

15 m

Successfully deposited capsules onto bothglass and graphite fibers using a solution dipcoating procedure

Capsule Deposit On Fibers

MICROVASCULAR COMPOSITES


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Objective:

DoD Benefit:

Technical Approach:

Budget:

$K

Major Reviews/Meetings:

FY05 FY06 FY07 FY08 FY09 FY10

504,311 1,242,709 1,047,076 1,115,244 1,057,424 500,920

To achieve synthetic reproduction of autonomicfunctions, such as self-healing and self-cooling,for aerospace platforms through creation andintegration of complex materials systemscontaining microvasculararchitectures.

(a) Natural models of microvascular systemsare studied to guide the engineering design ofoptimal networks for self-healing and self-cooling structural composites. (b) Thesenetworks are fabricated using direct-writeassembly techniques while integrating materialcomponents that realize the desired multi-

functionality. (c) A full compliment ofexperimental and analytical techniques areemployed to demonstrate system efficiency.

The advances in self-healing and self-coolingcomposite structures will lead to the increaseof reliability and responsiveness of aerospacevehicles allowing longer flight time and

reduced chance for unexpected failure.

30 August 2006: Seattle, WA 20 August 2007: Urbana, IL21 August 2008: Arlington, VA31 August 2009: Urbana, IL

Nature01

MICROVASCULAR COMPOSITES(UIUC/Duke/UCLA: White et al)

MURI 05

PM:B. L. Lee (NA); Co-PM:Hugh Delong (NL)

Mi l H li


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Microvascular HealingPerformance Comparison

Optimal pressure profiles for dynamic pumping enable 100%

healing efficiency for repeated healing cycles

MURI 05


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Pressure Driven Flow Oscillation

Qualitative match between experimental and simulation results

Simulation of pump driven oscillation in a T-junction Experiment with pump driven oscillation in a 25 m simulated crack

Simulation

Experiments

Interface folding Packet of well mixed

fluid

MURI 05

Engineering Design Of


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Multiple Network:2 part epoxy(Toohey et al. Adv. Func. Mat. 2009)

Interpenetrating Network:2 part epoxy(Hansen et al., Adv. Mat. 2009)

Single Network:DCPD/Grubbs(Toohey et al, Nature Materials, 2007)

Engineering Design OfMicrovascular Network

MURI 05

3D Microvacular Composites Via


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3D Woven Preform Integration of Sacrificial Fibers Resin Infusion

3D Woven Composite Fiber Removal 3D Vascular Composites

3D Microvacular Composites ViaSacrificial Fibers

MURI 05

5 mm

Development of Sacrificial


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Treatment of PLA fibers by solvent-assisted catalyst diffusion

Drying

Development of SacrificialPolylactide (PLA) Fibers

When exposed to high temperature, a catalyst treated PLA fiber depolymerizes

into gaseous monomer thereby making the evacuation process very easy.

MURI 05


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Journal Covers

INTERACTIONS WITH


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University of BristolMultifunctional Materials Group

Ian BondHollow fiber delivery

EPFL Laussane

Laboratoire de technologie des composites et polymresJan-Anders Mnson, Vronique MichaudShape memory + self-healing

AFRL/RXPolymers and Composites Branches

Jeff Baur, Rich Vaia, Ajit RoySacrificial wax fibers, permeability testing, composites design

INTERACTIONS WITHOTHER RESEARCH GROUPS

Delft UniversityCentre for Materials

Sybrand van der ZwaagShaped encapsulation vesicles

MURI 05

Technology Transfer:


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Transitioning of capsule technology for self-healing composites, adhesive & coating

Key challenges are size scale and integration method

Technology Transfer:

SELF-HEALING MATERIALS

2006-2009: STTR (AF) on self-healingaerospace composites

2009: STTR (Army) on self-healing, self-diagnosing multifunctional composites

Self-healing coatings for electronics

Application development for adhesive

MURI S i ff STTR08 THERMALLY


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O

O

O

O

O

Mendomer 401

O

O

O

O

O O

Mendomer 602

Goals:

Less brittle and lower glass transitiontemperature (Tg) for better adhesionand conformal coating

MURI Spin-off>>STTR08: THERMALLYREMENDABLE COMPOSITES

19

HEAT

THERMALLY REMENDABLEPOLYMERS (UCLA: Wudl)

C O O

O

O

4

N

N

O

O

3

O+ N

O

O

O

N

O

OPolymer

N N

O

OO

O

MURI05

4th DAMAGE 4th HEALING

5th HEALING5th DAMAGE

Healing ofDelamination

StrainEnergy (mJ)

HealingEfficiency (Time)

Virgin 10.04

1st healing 8.68 86.4% (1 hr)

2nd healing 8.88 88.4% (2 hr)

3rd healing 9.82 97.8% (3 hr)

4th healing 9.42 93.8% (3 hr)

Crosslink bonds of Diels-Alder cyclo-addition

polymers are thermally reversible and can bereestablished after separation (unlike epoxy)

Fabricated CFRPs with thermally remendablematrix materials and resistive heating network ofcarbon fiber reinforcement

Demonstrated multiple rounds of healing ofdelamination and microcracks

Resistive heating is dependent on layuporientation and most uniform with surfaceelectrodes laid at 45 relative to fibers Structural properties of CFRPs are comparableto traditional epoxy based CFRPs

Core10: BIO INSPIRED STRUCTURAL


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Core10: BIO-INSPIRED STRUCTURALREMODELING (UIUC: White/Moore)

Regeneration in biology: New approach: Dynamic polymers

+ inert scaffolds

*Dynamic polymers can be reversibly changedfrom liquid to solid and vice versa due todynamic covalent bond that can be triggered to

disassociate by an activating agent.

*


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VISION: EXPANDED

site specific

autonomic

AUTONOMICAEROSPACE



Self-Healing


Self-Powered

Biomimetics


Nano-materials

Multi-scaleModel

Micro- & Nano-

Devices

Manufacturing Sci


PIs & Co-PIs:

Abraham Stroock(Cornell U)Noel Holbrook(Harvard U)Patrick Kwon(Mich St U)Vikas Prakash(Case Western)Scott White(UIUC)*Jeffrey Moore(UIUC)*Nancy Sottos(UIUC)*

Jennifer Lewis(UIUC)*Philippe Geubelle(UIUC)*Kenneth Christensen(UIUC)*Jonathan Freund(UIUC)*Ajit Roy(AFRL/RXBT)Jeff Baur(AFRL/RXBC)

* MURI

Multi-physics Optimization of


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Multi-physics Optimization ofMicrovascular Network

Multi-objective constrained genetic algorithms Generalized finite element method for fluid/solid thermal problem

2D and 3D implementation for network optimization

Initial grid Optimal network

MURI 05

Enhancing Heat Transfer with


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Heat-TransferEnhancement >Increased pressuredrop

Enhancing Heat Transfer withWavy Microchannels

Serpentine microchannel

Flow direction

2a

Secondary flows due to waviness drawhot fluid from wall into main flowstreamCrest Trough

Efficiency of serpentine (wavy) channels in enhancingconvective heat transfer studied computationally todetermine optimal waviness and flow rates.

Various a/ studied (a=amplitude;=wavelength of waviness).

Bulk heat transfer in wavy channels comparedto that of a straight microchannel of equivalenthydraulic diameter.

Efficiency, :

MURI 05

PLANT-MIMETIC HEAT PIPES


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Robust heat transfer in the presenceof large gravitational and inertial

stresses.

Plant mimetic use of liquids at large

negative pressures within a microfluidic

heat pipe.

Fundamental understanding of

thermodynamics and transport

processes in this regime. Insights into plant strategies for the

management of negative pressures and

recovery from cavitation.

Objectives:

MEMS platform

Achievements:

Plant physiology

Elucidation of structure and

biochemistry xylem elements

implicated in autonomic refilling. Physical, chemical, and molecular

biological characterization of refilling.

Figure: AFM image of bordered pit

membrane.Fabrication.

Development of wick membrane in

silicon platform with unprecedented

stability (down to -200 bars - Figure). Development of MEMS sensor for

measuring pressures down to -500

bars.

Figure: Development and testing of

inorganic wick membrane. Stability

limit of liquid water. Complete stability

to -3 MPa (-30 bars). Absolute limit:

-20 MPa (-200 bars).

Perspectives:

Foundation of technical approachesand physical and biological

understanding to enable robust

engineering with liquids at negative

pressures.

Efficient, passive heat transfer with

small form factor and weight for

avionics cooling.

0%

20%

40%

60%

80%

100%

0 10 20 30

%intact

Pressure ( -MPa)

cavitatedintact

silicon solgel

PLANT-MIMETIC HEAT PIPES(Cornell U / Harvard U: Stroock)

THERMAL MANAGEMENT OF


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ACCOMPLISHMENTS:

Developed molecular dynamics (MD) computationaltools to study the effect of CNT side wallfunctionalization with CH2 molecules on the interfacethermal conductance at the atomistic scale

Simulated two axially aligned CNTs embedded inepoxy polymer, one is being heated and thermalenergy taken out through the other.

The temperature drop between the CNT decreaseswith increasing functionalization, but the interfaceresistance does not diminish to zero even with

saturation of the functionalization

MD simulation ofCNT embedded inpolymer network

Effect of CNT polymerfunctionalization on interface

thermal resistance

b c d e

THERMAL MANAGEMENT OFINTERFACE (AFRL/RX: Roy)

BACKGROUND:

Lack of knowledge in materials design for improvingthermal conductivity of fiber reinforced composites

At least 20x improvement of through-the-thicknessthermal conductivity (to ~ 7-10 W/mK) is desired

OBJECTIVE:

To establish multiscale modeling for multifunctionaldesign integrated with processing of materials

To enhance thermal conductivity of composites byusing nano-constituents on carbon fibers to form athermal pathway network through the matrix phase

DoD BENEFITS:

Establishment of fiber reinforced composites withenhanced through-the-thickness thermal properties

for aerospace platforms Transition of the computational modeling capability

for innovative thermal interface design of composites

S O P


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VISION: EXPANDED

site specific

autonomic

AUTONOMICAEROSPACE



Self-Healing


Self-Powered

Biomimetics


Nano-materials

Multi-scaleModel

Micro- & Nano-

Devices

Manufacturing Sci


PIs & Co-PIs:

Gregory Huff(Texas A&M)Akira Todoroki(Tokyo Tech)fu-Kuo Chang(Stanford U)*Peter Peumans(Stanford U)*Boris Murmann(Stanford U)*Philip Levis(Stanford U)*Andrew Ng(Stanford U)*

Rahmat Shoureshi(U Denver)*Robert McLeod(U CO)*Greg Carman(UCLA)*Yong Chen(UCLA)*Frank Ko(U Brit Columbia)*Somnath Ghosh(Ohio St U)*^John L. Volakis(Ohio St U)Roberto Rojas(Ohio St U)^Stephen Bechtel(Ohio St U)^Dick James(U MN)^Max Shtein(U Mich)^Nick Kotov(U Mich)^Ben Dickinson(AFRL/RWGN)Greg Reich(AFRL/RBSA)Jeff Baur(AFRL/RXBC)

* MURI; ^ GameChanger

BUILT-IN SENSING NETWORK


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Stretchable Matrix

Autonomous System

Multi-Scale Design,Synthesis & Fabrication

Sensors(temperature,

pressure,strain, etc)

Local neurons(processor, memory,

communicationdevices)

BUILT-IN SENSING NETWORK(Stanford/UC/DU/UCLA: Chang et al)

MURI 09

Synaptic Circuits

Synapse:

Cognition and decision-making aredetermined by a relative level ofcumulative signal strength with respectto the synapse threshold values

Biological sensory systems

rely on large numbers ofsensors distributed overlarge areas and arespecialized to detect andprocess a large number ofstimuli. These systems arealso capable to self-organizeand are damage tolerant.

PM:B. L. Lee (NA); Co-PM:Hugh Delong (NL)


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SENSORS/ACTUATORS FOR MAV


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Flow Sensing Hairs - Principles of bio hairs

understood, but translation to engineered

system with similar performance is not

Models - Models for hair feedback control

have not been examined

Materials - Silicon or polymer hairs with

optical, piezoresistive, or capacitive

transduction shown Carbon nanotube (CNT)

gauge factor to 1000 for single-CNT devices,

~2 for traditional gauge factors, limited work

on CNT array strain sensing, even less on fiber

Artificial Hair Concept - CNT arrays on

rigid fibers have the required hair rigidity/

dimension, displacement sensitivity, material

robustness, and design flexibility to enable

integrated flow sensing to detect gust

alleviation and enable complex maneuvering

Model - Hair length vs. boundary layer

thickness can be optimized for increased

sensitivity

Materials - CNT array mechanics are highly

dependent on morphology, but vertically

aligned CNT (VACNT) sensor yields nearly

linear resistance change with strain

MAIN ACHIEVEMENTS:

Artificial Hair Model - Developed viscoelastic, nonlinear

fluid reaction hair sensor model Explored design

geometry & material for individual hair performance

Materials - Characterized morphology effect of VACNT

array mechanics Developed and characterized first

VACNT-based electromechanical flow/strain sensor

HOW IT WORKS: Model - Numerically solve hair sensor governing

equations to explore and optimize design

Materials - Compression reorients CNTs, reducing

electrical resistance Force imparted to hair converted toelectrical signal within sensor pore

ASSUMPTIONS AND LIMITATIONS: Model - Assume 1-way interaction (flow to hair) with

parallel surface, small deflections, rt circular X-section

Materials - Repeatable and uniform CNT deposition

Robust adhesion of CNTs to carbon fiber with

environmental changes

Current Impact Optimal hair lengths are 50-100% of (d99)

boundary layer thickness for steady flow

Pore sensitive to depth, not width with 1.5-

3 micron level deflections expected

Planar VACNT sensor gauge factor of 30

Planar flow sensor created on copper

substrate (difficult)

Planned Impact Test CNT sensor in wind tunnel (Eglin AFB)

Enhance sensor gauge factor

Extend to fuzzy fiber for artificial hair

Extend model to oscillatory flow

Eval. sensor impact on vehicle performance

Research Goals Model & validate artificial hair model

Understand parameter space for optimal

sensor performance

Understand and model physics of

electromechanical response of CNT array

Demonstrate flow sensing capability inside

wind tunnel

CNT-Based Artificial Hair Airflow Sensor

STATEOFTHEART

END-OF-PHASEGOAL

QU

ANTITATIVEIMPACT

NEWINSIGHTS

Nanoindentation of foam-like and beam-like VACNT arrays

Schematic of proposed CNT-coated carbon fiber sensor

Planar CNT Flow Sensor Prototype on DMA

Localized CNTBuckling

SENSORS/ACTUATORS FOR MAV(RW: Abate; RB: Reich; RX: Baur)

LOAD-BEARING ANTENNAS


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Ohio State University / College of Engineering

CHANGING COURSE FOR UAVS

Ohio State electrical and computer engineers have solved a radar and surveillanceproblem for unmanned aerial vehicles (UAVs) with the help of atypicalcollaborators: embroidery experts.

The UAVs ranging in size from more than 40 feet long to ones that could beeasily confused with hi-tech Frisbees can serve many functions, fromsurveillance to data collection. However, their relatively small size cannot

accommodate the large antennas necessary for long-distancecommunication. So the engineers are developing new technology to weavesensor and communication antenna systems into the structure of the UAVs.

This research is part of the three-year, $3.5 million GameChanger program, now inits final year and funded by the Air Force Defense Research Sciences Program.

The GameChanger philosophy involves a different perspective on aircraft design:Instead of mechanical and aerospace engineers designing a plane foraerodynamics, in this case electrical and computer engineers dictate the initialform of the plane based on its radar or surveillance function.

To weave the sensor and communication systems into the structure of the aircraft so the UAV itself becomes the antenna researchers needed lightweight,load-bearing, flexible materials that could conform to the aircrafts surface.Polymers fit the required criteria, but first researchers had to determine how to printantennas on them, as polymers are not mechanically compatible with traditionalconductors.

News in Engineering

antenna layer:microstrip patches,dipoles, bowties and etc.

feeding layer:feeding networks,impedance tuning stubs

circuits layer:filters, mixers,LNAs and etc.

LOAD BEARING ANTENNAS(OSU/U Mich/U MN/UCLA: Volakis)

LOAD-BEARING ANTENNAS


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Design next generation antennas (broadband and narrowband) that are

structurally ruggedized, reconfigurable and sufficiently miniaturized forUAV applications.

Develop a new class of materials for load-bearing/conformal/light-weightantennas (incl. ferroelectric, ferromagnetic, multi-ferroic, bondable polymercomposites, 3D textiles and nanomaterials).

Develop analytical techniques for tractable electro-magneto-thermo-mechanical theory from fully coupled 3-D equations.

Integrate new antenna designs into a lightweight structure and developfigures of merit (design rules) for structural integration.

Objectives:

Main Achievements:

Developed new technology by embroidering metal coated electronic fibers(e-fibers) on polymers for conformal load bearing antennas.

Designed and tested volumetric and planar woven antennas based on e-fibers and polymer composites

Demonstrated the feasibility of first everCNT antenna whose gain isequivalent to the perfectly conducting (but rigid) patch antennas.

Developed coupled multi-physics & multi-scale models for electro-magnetic composite materials undergoing mechanical excitation.

Developed models to tune antenna via ferroelectrics materials undermechanical and thermal loads

Developed fully overlapping Domain Decomposition Technique for FiniteElement Modeling of small features in large media

antenna layer:microstrip patches,dipoles, bowties and etc.

feeding layer:feeding networks,impedance tuning stubs

circuits layer:filters, mixers,LNAs and etc.

LOAD BEARING ANTENNAS(OSU/U Mich/U MN/UCLA: Volakis)

GameChanger07PM:B. L. Lee (NA); Co-PM:Arje Nachman (NE)

VISION EXPANDED


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VISION: EXPANDED

site specific

autonomic

AUTONOMICAEROSPACE



Self-Healing


Self-Powered

Biomimetics


Nano-materials

Multi-scaleModel

Micro- & Nano-

Devices

Manufacturing Sci



PIs & Co-PIs:

Ray Baughman(U Texas Dallas)Nicolas Triantafyllidis(U Mich)John Shaw(U Mich)Shiv Joshi(NextGen)Sharon Swartz(Brown U)Nakhiah Goulbourne(VA Tech)Benjamin Shapiro(U MD)

Elisabeth Smela(U MD)Patrick Mather(Syracuse U)H. Jerry Qi(U CO)Martin Dunn(U CO)Minoru Taya(U WA)Frank Ko(U Brit Columbia)Hiroyuki Kato(Hokkaido U)Xin Zhang(Boston U)C. T. Sun(Purdue U)Thomas Siegmund(Purdue U)Aaron Dollar(Yale U)A. John Hart(U Mich)Greg Reich(AFRL/RBSA)Richard Vaia(AFRL/RXBN)

^ YIP

VISION EXPANDED


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44

VISION: EXPANDED

site specific

autonomic

AUTONOMICAEROSPACE



Self-Healing


Self-Powered

Biomimetics


Nano-materials

Multi-scaleModel

Micro- & Nano-

Devices

Manufacturing Sci



Environ

PIs & Co-PIs:

Max Shtein(U Mich)+Henry Sodano(U FL)Dan Inman(VA Tech)Sven Biln(Penn St U)Michael Strano(MIT)Greg Carman(UCLA)Gleb Yushin(GA Tech)

Minoru Taya(U WA)*Paolo Feraboli(U WA)*Martin Dunn(U CO)*Ronggui Yang(U CO)*Kurt Maute(U CO)*Se-Hee Lee(U CO)*Y. Sungtaek Ju(UCLA)*Tom Hahn(UCLA)*

Dan Inman(VA Tech)*Ioannis Chasiotis(UIUC)*Carl Schulenburg(PowerMEMS)Tim Fisher(Purdue U)Benji Maruyama(AFRL/RXBN)Thuy Dang(AFRL/RXBN)Michael Durstock(AFRL/RXBN)

+ PECASE; ^ YIP; * MURI

INTEGRD ENERGY HARVESTING


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Objective:

To develop self-powered load-bearingstructures with integrated energy harvest/storage capabilities, and to establish new multi-functional design rules for structuralintegration of energy conversion means.

DoD Benefit:Self-powered load-bearing structures withintegrated energy harvest/storage capabilitieswill provide meaningful mass savings andreduced external power requirements over awide range of defense platforms includingspace vehicles, manned aircraft, unmanned

aerial vehicles, and ISR systems.

Technical Approach:

(a) A combination of experimental andanalytical techniques are employed to advancethe efficiency of the energy conversion means(as an integral part of load-bearing structures)and to optimize their multifunctionalperformance and ability to cover larger areas.

(b) Multifunctional composites are created with

individual layers acting as photovoltaic/thermo-electric/piezoelectric power harvesting andelectrochemical power storage elements.

Budget:

$K

FY06 FY07 FY08 FY09 FY10 FY11

693,335 1,169,560 1,180,608 1,219,324 1,179,991 568,571

Major Reviews/Meetings: 29 August 2007: Seattle, WA 5 August 2008: Boulder, CO

11 August 2009: Blacksburg, VA18 August 2010: Los Angeles, CA

polymersolar cells

thermo-electrics (TE)antenna system underthe wing with TE

polymerbattery cells

INTEGR D ENERGY HARVESTING(U WA/U CO/UCLA/VPI: Taya et al)

MURI 06

PM:B. L. Lee (NA);

Co-PMs: Joan Fuller (NA), David Stargel (NA)

INTEGRD ENERGY HARVESTING


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Year 4 Highlights

Developed new anti-reflection surface coating inspired bymoth eyes for solar cells with higher transmittance

Process scale-up of dye-sensitized solar cells (DSSC) Integrated the DSSC onto a quasi-wing structure and

confirmed the endurance under 44,000+ bending cycles Shrink-fit integration and FGM electrodes for linear TE

modules with increased durability Microwave synthesis of nano-particles of Bi2Te3 Design of scalable and stretchable thin-film Li ion

batteries for UAV structures Modeling of electrochemical and mechanical response of

solid-state electrolyte and their morphology effects

Simulations predicting onset of mechanical failure leadingto capacity fade in agreement with experiments

Experimental characterization of cracking and twining in Sianode with Li ion insertion (first-everobservation).

Assessed battery survivability in co-curing environment UAV test bed at U Colorado

INTEGR D ENERGY HARVESTING(U WA/U CO/UCLA/VPI: Taya et al)

MURI 06

4-Point Bending Test

DSSC

e

e

e

e

e

e

e

e

Li+

Li+Li+

Li+

Li+

A

e

e

e

e

e

e

e

e

Li+

Li+Li+

Li+

Li+

A

Fe-SMA

Cu-SMA

SCIENTIFIC CHALLENGES &


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SCIENTIFIC CHALLENGES &PROGRAM ACHIEVEMENT

Self-healable or in-situ remendable structural materials(1st-everprogram; world lead)

Microvascular composites for continuous self-healingand self-cooling systems (1st-everprogram; world lead)

Structural integration of energy harvest/storagecapabilities (1st-everprogram on structurally integrated multipleenergy harvest capabilities; DoD lead)

Neurological system-inspired sensing/diagnosis/actuation network (potlworld lead)

Mechanized material systems and micro-devices forreconfigurable structures (DoD lead)

Experimental nano-mechanics (DoD lead)

PROGRAM TRENDS


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NAME: B. L. Lee

BRIEF DESCRIPTION OF PORTFOLIO:Basic research for integration of advanced materials and micro-systems into future Air Force systems requiring multi-functionality

LIST OF SUB-AREAS:

Life Prediction (Materials & Devices);Sensing & Diagnosis;Micro-, Nano- & Multi-scale Mechanics;Multifunctional Design (Shape Change);Multifunctional Design (Property Tuning);


PROGRAM TRENDS

EXPERIMENTAL NANOMECHANICS


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Cracks were imaged in nanometer

scale by AFM to obtain their geometryand the grain structure at the crack tip.

Doping caused a drop in fracturetoughness of laminated polysiliconwhile it increased the toughness of

coarse grain polysilicon films

10 m

Edge crack

Substrate

Specimen

150 m

25 m long sharp cracks created in 2 mthin polycrystalline silicon specimens bynanoindentation near free edge

Crack tip

500 nm

EXPERIMENTAL NANOMECHANICS(UIUC: Chasiotis)

MULTISCALE ANALYSIS:


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50

U SC S SOn-Going Research

72

Cracks were imaged in nanometerscale by AFM to obtain their geometryand the grain structure at the crack tip.

Doping caused a drop in fracturetoughness of laminated polysilicon

while it increased the toughness ofcoarse grain polysilicon films

10 m

Edge crack

Substrate

Specimen

150 m


Crack tip

500 nmEXPERIMENTAL NANOMECHANICS(UIUC: Chasiotis)

36

MAIN ACHIEVEMENTS:

HOW IT WORKS: The non-linear mechanical response of hierarchical

structure of proteins is caused by the structural transition

mechanisms during deformation.

The alterable structure enables proteins to combine

disparate material properties (flexible, strength,

robustness).

The structural and mechanical property of

intermediated filaments are altered by point mutation.

Current engineering materialsRemain limited in their ability to

combine disparate properties such

as high strength, robustness,

self-healing, mutability

Biological materials and structures Show intriguing material properties combine

disparate properties in a single material

De novo materials design Requires bottom-up structural design, from nano

to macro need to understand structure-property

links in biological materials

Multi-scale analysis of biological

structures Intermediated filaments, found in cells nuclear

envelop, provide intriguing mechanical properties

provide great extensibility, strength, mechanical

robustness, and ability to self-heal structural

analysis reveals a intricate design, from atomistic to

macroscopic.

IMPACT Provide the first atomic

mechanism and condition

of the stiffening behaviorof alpha-helical materials.

Developed model to link

the microscopic structural

transition with the

macroscopic behavior.

Enables to seek the

mechanical property of

protein materials with

mutation.

TRANSITIONS New MURI project for fiber design PI visitedAFRL in 2010 (Wright-Patterson AFB) PI

awarded PECASE

FUTURE RESEARCH GOALS Facilitate merger of structure, material

property and function through the bottom-up

multi-scale design, from atomic to macroscopicbehavior.

Quantitatively understand the assembling

process of protein materials and factors to

affect the material property of those assembled

structures.

Quantitatively understand the cascaded

activation of mutations and their effect on

material performance.

Provide basis for new engineering paradigm

to functionalize the hierarchical structural

materials (e.g. new composites or polymers

combine high flexibility, ultimate strength, self

healing and robustness): novel materials for

advanced Air Force technologies

Multi-scale approach to understand biological protein materials & translate design concepts into engineering applications

STATUS

QUO

END-OF-PHASEGOAL

QUANTITATIVEIMPACT

NEWINSIGHTS

Study of nuclear lamina

(meshwork of filaments).

Discovered the flaw

tolerance of this structure is

caused by non-linear

mechanical response of

intermediate filaments.The adhesion energy of

the lamin tail is changed

due to mutation, leading

to altered mechanical

response of filaments

Mechanism of the - transition caused by mechanical force.

Structural transition related

Non-linear mechanical property

Qin, Kreplak, Buehler, PRL, 2010, PLOS ONE, 2009

Qin, Buehler, PRL, 2010

Example of hierarchical structure of lamin at nuclear

lamina.

Materials science paradigm

applied to the hierarchical

structure of protein

materials.

Buehler,Nature Nanotechnology,1

STRUCTURAL HIERARCHIES INPROTEIN MATERIALS (MIT: Buehler)

MULTISCALE ANALYSIS:


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51

U SC S SJoint ARO/AFOSR/NSF Workshop

72

Cracks were imaged in nanometerscale by AFM to obtain their geometryand the grain structure at the crack tip.

Doping caused a drop in fracturetoughness of laminated polysilicon

while it increased the toughness ofcoarse grain polysilicon films

10 m

Edge crack

Substrate

Specimen

150 m


Crack tip

500 nmEXPERIMENTAL NANOMECHANICS(UIUC: Chasiotis)

36

MAIN ACHIEVEMENTS:

HOW IT WORKS: The non-linear mechanical response of hierarchical

structure of proteins is caused by the structural transition

mechanisms during deformation.

The alterable structure enables proteins to combine

disparate material properties (flexible, strength,

robustness).

The structural and mechanical property of

intermediated filaments are altered by point mutation.

Current engineering materialsRemain limited in their ability to

combine disparate properties such

as high strength, robustness,

self-healing, mutability

Biological materials and structures Show intriguing material properties combine

disparate properties in a single material

De novo materials design Requires bottom-up structural design, from nano

to macro need to understand structure-property

links in biological materials

Multi-scale analysis of biological

structures Intermediated filaments, found in cells nuclear

envelop, provide intriguing mechanical properties

provide great extensibility, strength, mechanical

robustness, and ability to self-heal structural

analysis reveals a intricate design, from atomistic to

macroscopic.

IMPACT Provide the first atomic

mechanism and condition

of the stiffening behaviorof alpha-helical materials.

Developed model to link

the microscopic structural

transition with the

macroscopic behavior.

Enables to seek the

mechanical property of

protein materials with

mutation.

TRANSITIONS New MURI project for fiber design PI visitedAFRL in 2010 (Wright-Patterson AFB) PI

awarded PECASE

FUTURE RESEARCH GOALS Facilitate merger of structure, material

property and function through the bottom-up

multi-scale design, from atomic to macroscopicbehavior.

Quantitatively understand the assembling

process of protein materials and factors to

affect the material property of those assembled

structures.

Quantitatively understand the cascaded

activation of mutations and their effect on

material performance.

Provide basis for new engineering paradigm

to functionalize the hierarchical structural

materials (e.g. new composites or polymers

combine high flexibility, ultimate strength, self

healing and robustness): novel materials for

advanced Air Force technologies

Multi-scale approach to understand biological protein materials & translate design concepts into engineering applications

STATUS

QUO

END-OF-PHASEGOAL

QUANTITATIVEIMPACT

NEWINSIGHTS

Study of nuclear lamina

(meshwork of filaments).

Discovered the flaw

tolerance of this structure is

caused by non-linear

mechanical response of

intermediate filaments.The adhesion energy of

the lamin tail is changed

due to mutation, leading

to altered mechanical

response of filaments

Mechanism of the - transition caused by mechanical force.

Structural transition related

Non-linear mechanical property

Qin, Kreplak, Buehler, PRL, 2010, PLOS ONE, 2009

Qin, Buehler, PRL, 2010

Example of hierarchical structure of lamin at nuclear

lamina.

Materials science paradigm

applied to the hierarchical

structure of protein

materials.

Buehler,Nature Nanotechnology,1

STRUCTURAL HIERARCHIES INPROTEIN MATERIALS (MIT: Buehler)

2-5 May 2011, Arlington, VA

WORKSHOP ONMULTISCALE EXPERIMENTS

Ioannis Chasiotis (U Illinois), Chair

WORKSHOP ONMULTISCALE ANALYSIS FOR

MULTIFUNCTIONAL DESIGNSomnath Ghosh (Johns Hopkins U), Co-Chair

Tom Hahn (UCLA), Co-Chair

WORKSHOP ONCOMPUTATIONAL MULTISCALE

MATERIALS MODELINGSomnath Ghosh (Johns Hopkins U), Chair

Joint Organizing Committee:Bruce LaMattina (ARO), Co-Chair

B.-L. (Les) Lee (AFOSR), Co-ChairGlaucio Paulino (NSF), Co-Chair

3 Workshop ChairsJeff Baur(AFRL/RX)Ajit Roy (AFRL/RX)

John Beatty (ARL/WMRD)Ernest Chin (ARL/WMRD)Eric Wetzel (ARL/WMRD)

James Thomas (NRL)

NANOMATERIALS FOR


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Engineered Nanomaterials for

Multifunctional Structures: Shape Memory AlloyNano-rodsfor Actuation

Carbon Nanotube(CNT) Grown on Graphite Fibers

CNT-BasedContinuous FiberReinforcement

Layer-by-Layer(LBL) Assembled CNT Composites

Alignmentof Nanoreinforcement

Graphite / Bi2Te3 / Bi2Se3 / MoSe2Nano-platelets

Gecko"AdhesionUsing Ordered Arrays of CNTs

Self-Healing ViaNanoscale Capsules

Reactive CNTfor Active Armors ExperimentalNanomechanics

U Wisconsin U Michigan Brown U U Delaware Stanford U U IllinoisCarbon Solutions Case Western CU Aero3Tex UC San Diego MIT U Texas Dallas UCLA

STRUCTURES: 06 INITIATIVE

NANOMATERIALS FOR


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Engineered Nanomaterials for

Multifunctional Structures: Shape Memory AlloyNano-rodsfor Actuation

Carbon Nanotube(CNT) Grown on Graphite Fibers

CNT-BasedContinuous FiberReinforcement

Layer-by-Layer(LBL) Assembled CNT Composites

Alignmentof Nanoreinforcement

Graphite / Bi2Te3 / Bi2Se3 / MoSe2Nano-platelets

Gecko"AdhesionUsing Ordered Arrays of CNTs

Self-Healing ViaNanoscale Capsules

Reactive CNTfor Active Armors ExperimentalNanomechanics

U Wisconsin U Michigan Brown U U Delaware Stanford U U IllinoisCarbon Solutions Case Western CU Aero3Tex UC San Diego MIT U Texas Dallas UCLA

STRUCTURES: 06 INITIATIVE

PIs & Co-PIs:

Nancy Sottos (UIUC)Vikas Prakash (Case Western)Ajit Roy (AFRL/RXBT)Frank Ko (U Brit Columbia)*Ray Baughman (U Texas Dallas)A. John Hart (U Mich)Michael Strano (MIT)

Greg Carman (UCLA)Ronggui Yang (U CO)*Se-Hee Lee (U CO)*Tim Fisher (Purdue U)Ioannis Chasiotis(UIUC)John Kieffer(U Mich)Nicholas Kotov(U Mich)Jimmy Xu(Brown U)Erik Thostenson(U Del)Mrinal Saha(OK St U)Alexander Bogdanovich(3Tex)Yuntain T. Zhu(NC St U)Kelechi Anyaogu(Nico)David L Carnahan(NanoLab)

^ YIP;* MURI

SUMMARY


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54

SUMMARY

The program is fully focused on the establishment of advanced

multi-functional aerospace structures. A major progress has been made in pursuing a new vision for

autonomic systems and providing research support for baselinemultifunctional materials and microsystems.

Three initiatives for autonomic aerospace structures are highlysuccessful: microvascularcomposites(MURI 05),structurally integrated energy harvest/storage capabilities

(MURI 06) and load bearing antennas(GameChanger 07).

Three new initiatives are implemented for reconfigurablemultifunctional structures,energy harvesting from aerospace

environment and neurological system inspired sensorynetwork(MURI 09).

A new initiative is planned for multiscale analysis for multi-functional designin close collaboration with AFRL TD PIs,

AFOSR PMs and the colleagues at other funding agencies.

Back-Up Slides


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Back Up Slides

Modeling and Simulation for


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56

Electro-Thermo-MechanicalComputational Tools

Domain Decomposition

Techniques to Model Nanowires

Inside Polymer Composites

OBJECTIVES

Develop integrated multi-scale multi-physics computational model for analysis and

design of load bearing antenna.

Robust finite element for coupled electro-magnetic and mechanical structural response Multi-scale effects through the incorporation of semi-analytical methods

Homogenization methods for continuum constitutive models to be inserted in

macroscopic analysis

Methods for microstructural design to facilitate optimal property distribution

ACCOMPLISMENTS High-performance parallel computational framework

Electro-magnetic code for solving Maxwells equations

Finite deformation model/code for structural mechanics under dynamic loading with

hyper-elastic material model Coupling of EM and Dynamic Codes

Multi-time scaling algorithm for coupling mechanical and EM solutions in real time

CHALLENGES

1. Large matrix system needed for highprecision;

2. Ill -conditioned matrices haveconvergence difficulty;

3. Repetitive re-meshing for in situdesigns

Modeling Small UWB Antennas

on UAV Platform

Feed

50 x

y

z

Planar Spiral

Mesh on Planar

Spiral

Detailed Mesh Background Mesh

gConformal Load Bearing Antennas

ACTIVE MATERIALS FOR


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48

To design better actuators/morphingdevices using shape memory alloyhoneycomb which combines benefits ofcellular structures and monolithic SMAs

Objectives:

After non-uniformity due to structurallevel instabilities at moderate strains, thedeformation pattern becomes uniformagain upon further straining .

This morphing behavior reverses underunloading.

CELLULAR SHAPE MEMORY

STRUCTURES (U Mich: Triantafylli)

47

Forest-drawn carbon nanotube sheets

have higher specific strength than steel.

Charge injection of carbon nanotubesheets produces giant width-directionactuation (>3.3 X) from 80 to 1900 K.

Sheets CONTRACT in nanotubedirection by up to 2% during actuation.

Generated stress is 32 times the stressgeneration capability of natural muscle.

Motor

Nanotube Forest

Mandrel

Meterlongcarbonnanotubesheet

Forest

Sheet (right) being spun

from nanotube forest (left)

Side view of above sheetspinning from forest

300 K, 0 kV

300 K, 5 kV

1500 K, 5 kV

NANOTUBE ARTIFICIAL MUSCLE(U Texas Dallas: Baughman)

ADAPTIVE STRUCTURES

BAT-INSPIRED MORPHING WING


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CURRENTSTAT

E

NEWINSIGH

TS

QUANTITATIVEIMPACT

END-OF-PHASEGOAL

MAIN ACHIEVEMENTS (Contd): Current Impact

Inertial Measurement (IM)

Acceleration and angular velocities recorded forstraight and obstructed flights Dorsal mount miniature wireless IM Unit (IMU)

Mechanical Characterization of Bat Membrane Strain experiments Constitutive modeling

-Fiber bundle dist.-Fiber bundle comp.-Base matrix corrugation

Result satisfy materialanisotropy property

MAIN ACHIEVEMENTS:

Skeletal Assembly Bones assembled in CAD CAD model guides

mechanical design

Robotic Wing 4 DOF

High flapping frequency

Data Smoothing, Motion Trajectory

Motion capture dataimproved

Motion trajectory definedfor humerus and radius

High-fidelity models forcomponents and integratedstructure representative of a

bat-wing

Quantitative evaluation offlight performance, energyconsumption and efficiency

Estimates of weight, volumeand geometry of a roboticbat-wing

Guidelines to develop an

autonomous, hovering, highlymaneuverable, bat-like MAV

Reconfigurable hovering ultra-maneuerablebat technologies (RHUMBAT) offers

potential benefits in operational robustness. Most research has focused on recreating

three degrees of freedom (DOFs) assoc

with this motion: flap, lag, and feather Small vehicle size and low inertia make fine-

scale control required for envisionedmissions difficult.

Our unique approach considers actuatorsthat are distributed across the structure.

We provide detailed analysis for selection ofactuation DOF using motion capture andrevealing complex morphologies of joints.

Wing membrane characterization showsthickness inhomogeneities to be consideredin materials selection.

In depth understanding of

bat skeletal structure andskeletal dynamics duringflight

Materials analysis forstructural and aerodynamicsurfaces

Translation of bat dynamicsto robotic system

Biological Experiments Examined wing fiber

under polarized light Guides constitutive

model development

IMU

Right wing assembly

Preliminary design

Wing fibersImproved suturing and biaxial setup

Simulated Stress-Strain CurveBiaxial loading

Strain analysis

(NextGen/Brown U/VPI: Joshi)

REVERSIBLE SHAPE MEMORYS CO


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Commonly Used Shape Memory

Polymers (SMP) One-way shape memory (SM) effects Not

being able to recover the temporary shape

No design tools available

Two-way Shape Memory Polymers Two-way SM effects using switching

between two stable states No two-way SM

due to intrinsic material property change

Two-way SMPs Applications Require combinatorial methods for

material synthesis, modeling, and design.

Two-Way SMP by the Concept of

Opposing Microstructural-Scale

Spring Two opposing spring can generate motions

if one or both of them can change properties

as temperature changes Opposing spring

can be realized through material/structure

design at micro-scale.

MAIN ACHIEVEMENTS: Demonstrate two-way shape memory effects assisted by

external force.

Fabricate reversible free-standing two-way shape

memory polymer composites.

HOW IT WORKS: Stretched induced crystallization (SIC) can relax the

stress Opposing microstructural-scale spring creates

reversible free-standing two-way SMP Shape memory

effect is fully reversible.

Current Impact First free-standing two-way SMP based onintrinsic material property change Large

reversible actuation strain

Planned Impact Two-way SMPs for multifunctionalstructural Design tools that enhance robust

design Novel applications based on two-

way SMP

Research Goals Complete understanding of material

behaviors Design tools for novel

applications of these materials Explore

other polymer-based shape memory

materials Explore applications with AFRL

STATUSQUO

END-OF-PHASEGO

AL

Q

UANTITATIVEIMPACT

NEWINSIGHTS

Proposed applications: a) Rotational actuation

in shear to enable autonomous rotation for

mirror motion, wing joints. b) Reversible

blistering of two-way SMPs for variable

boundary layer aircraft control surfaces.

Ki Ks(T)Ki Ks(T)

The spring on

the left has a

constant

stiffness Ki and

the stiffness of

right spring Ksdepends on the

temperature.

SMPin shearStator

Rotor

Reversible TorsionVia SMP Shear

to mirror(a)

(b)

SMPin shearStator

Rotor


to mirror

SMPin shearStator

Rotor


to mirror(a)

(b)

Two-way shape

memory effect

assisted by an

external force

2W-SMP 2W-SMP is

stretched at

high T, then

cooled to low T

2W-SMP is

laid on top

of the

polymer

A polymer

layer is photo-

synthesized

on top.

0mn 1min 2min 3min 4min 5min 6min 7min

Heating Cooling

(Syracuse U / U CO: Mather)

Thermoelectric Module IntegrationMURI 06


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TE design

Analysis results

Phi TE Linear TELinear TE w/ FGM

and shrink-fit (1.25mm)Linear TE w/ FGM

and shrink-fit (2.5mm)Linear TE w/ FGM

and shrink-fit (2.5mm)

Generated temperature gapacross TE element (deg C)

338 344 344 346 394

Maximum normal stress onelectrode (Mpa)

-1100 -1200 -535 -591 -642

Maximum shear stress on

electrode (MPa) 146 617 329 311 337Maximum shear stress on TE

element (MPa)125 71 34 43 56

Power density (W/cm2) 0.80 0.87 0.87 0.89 1.15

Module efficiency (%) 12.8 13.3 13.3 13.4 14.8

Fe-SMA

Cu-SMA

Fe-SMA

Cu-SMA

Grazing material(Ag)

CNT

SMA

Electrode (Cu)

n-type: Mg2

Si0.96

Bi0.03

In0.01

p-type: Si0.93Ge0.05B0.02 Heat source side: Fe-SMA

Heat exhaust side: Cu-SMA

CNT in grazing material gives: locking Ag reducing the creep strain

Fe-SMA

Cu-SMA

450C

50C

Thermoelectric Module IntegrationMURI 06

Modeling and Simulation ofL d B i Li I B i

MURI 06


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e

e

e

e

e

e

e

e

Li+

Li+Li+

Li+

Li+

AMacro-scale (1D)

Micro-scale (1/2/3D)

input

discharge current

porosity

temperature

mech. loads

input

material system

particle geometry

outputcapacity (utilization*)

voltage (electric power)

Li concentration*

chemical eigenstrains*

deformation*& stress*

temperature*

output

particle Li concentration*

particle deformation*

particle stress* (degradation)

* as function of space and time

Multiscale framework allows connection between microscale behavior, e.g.,stress development, as a function of actual battery operating conditions

gLoad Bearing Li Ion Batteries

MURI 06

STTR10: HYBRID ENERGY HARVEST(P MEMS)


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Jan 09

Paramagnetic State

(Heating)

Ferromagnetic State

(Cooling)

OscillationAmplitude

Bi-Directional

Magnetic Force

SpringForce

SpringForce

MagenticForce

Perm-magnet Perm-magnet Perm-magnet

Force

FerromagneticState

ParamagneticState

StateTransition

Tcurie

Tcurie -1C Tcurie +1C

Temperature

Bi-directional

Extract work from phase transitions

Pairing solar panels with magneto-thermoelectric

power generator as active thermal backplane forsolar panel cooling and hybrid energy harvest

(PowerMEMS)

magneto-thermoelectricpower generator(STTR07)

ENERGY HARVESTING ONSPACECRAFT (P St t Bil )


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PROJECT SUMMARY

ACCOMPLISHMENTSAPPROACH

Objectives:

Team:

Develop system concepts for use of ElectrodynamicTethers (EDT) on an array of spacecraft in variety oforbits and for various missions

Address EDT performance parameters

Evaluate various system components required

Explore energy storage devices

Sven Biln, PI, and Jesse McTernan, Penn StateBrian Gilchrist, Co-PI, and Iverson Bell, Univ. MichiganRob Hoyt, Nestor Voronka, Co-Is, TUI, Inc.

Explore EDT system architecturesfor energy harvesting and storage

Employ tether simulation toolsTeMPEST and TetherSim forverifying performance

Develop and extend simulationtools to include energy harvestingmodes and new components

Define new architectures fori l i i d

ChipSat system concept development andfeasibility study

CubeSat system concept development andsolar panel comparison study

Large spacecraft system conceptdevelopment and voltage and currentmagnitudes study

Work underway to implement an energystorage module for TeMPEST

EDTs can be used toharvest energy andprovide propulsion

SPACECRAFT (Penn State: Bilen)

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