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MAE 438/538Smart Materials

Professor Deborah [email protected] Hall, Room 608

Tel. (716) 645-2593 X2243Fax. (716) 645-3875

Grading scheme forMAE 438

wTest 1 25%wTest 2 25%

wFinal 50%

Grading scheme forMAE 538

wTest 1 20%

wTest 2 20%

wFinal 40%

wPaper 20%

Test dates

wTest 1: Feb. 3, 2005

wTest 2: Mar. 22, 2005

Smart materials

Materials for

smart structures

Smart structures

Structures that cansense stimuli and

respond to them inappropriate fashions

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Civil structures

wBuildingswBridges

wPiers

wHighways

wAirport runways

wLandfill cover

Lightweight structures

w Aircraftw Satellitesw Turbine bladesw Automobilesw Bicyclesw Sporting goodsw Wheelchairsw Transportable bridges

Functions forstructures

Structural Vibration reduction

Self-sensing of strain/stress

Self-sensing of damage Electromagnetic interference (EMI)

shielding

Lightning protection Self-heating (e.g., deicing) Self-healing

Applications ofstrain-stress sensing

Traffic monitoring

Weighing (including weighingin motion)

Building facility management

Security

Structural vibration control

Applications ofdamage sensing

Structural healthmonitoring

Damage/microstructuralevolution study

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Damage sensingmethods

Acoutic emission

Electrical resistivitymeasurement

Optical fiber sensorembedment

Piezoresistivity Change of electrical resistivity due

to strain

Gage factor = fractional change inresistance per unit strain(more than 2)

Gage factor up to 700 attained incarbon fiber reinforced cement

Self-healing concept

Embedding microcapsules of monomer incomposite

Having catalyst in composite outside themicrocapsules

Upon fracture of microcapsule, monomermeets catalyst, thereby former a polymerwhich fills the crack.

Problems withself-healing

Toxicity of monomer

High cost of catalyst

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Types of smartness

Extrinsic smartness

Intrinsic smartness

Advantages ofintrinsic smartness

Low cost

High durability Large functional volume

Absence of mechanicalproperty loss

Advantages ofautomatic highway

vSafety

vMobility

Lane Lane

(a) (b)

Applications of materials

Topic 1

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Reading assignment

wChung, Composite Materials,Ch. 1 on Applications.

wAskeland and Phule, The Scienceand Engineering of Materials, 4th

Edition, Ch. 15 on Polymers.

Applications

wStructural applicationswElectronic applications

wThermal applications

wElectrochemical applications

wEnvironmental applications

wBiomedical applications

History of humancivilization

wStone Age

wBronze Age

wIron Age

wSteel Age

wSpace AgewElectronic Age

Types of materials

wMetals

wCeramics

wPolymers

wSemiconductors

wComposite materials

Ceramics

wIonic/covalent bonding

wVery hard (brittle)

wHigh melting temperature

wLow electrical/thermalconductivity

Examples of ceramics

wAl2O3 (aluminum oxide oralumina)

wFe3O4 (iron oxide or ferrite)

wWC (tungsten carbide)

wCement (silicates)

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Polymers

wMoleculeswSoft

wLow melting temperature

wLow electrical/thermalconductivity

(PVC)

2003 Brooks/Cole, a division of Thomson Learning, Inc. T homson Learning

is a trademark used herein under license.

2003Brooks/Cole,adivisionofThomsonLearning,Inc.ThomsonLearningisatrademarkusedhereinunderlicense.

Styrene Examples of polymers

wRubber

wPolyester

wNylon

wCellulose

wPitch

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Copolymer

Polymerblend 2003 Brooks/Cole, a division of Thomson Learning, Inc. Thoms on Learningis a trademark used herein under license.

2003Brooks/Cole,adivisionofThomsonLearning,Inc.ThomsonLearningisatrademarkusedhereinunderlicense.

Styrene-butadiene block copolymer

Branching

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2003Brooks/Cole,adivisionofThomsonLearning,Inc.

ThomsonLearningisatrademarkusedhereinunderlicense.

Types of polymer

wThermoplastic (softens uponheating)

wThermoset (does not softenupon heating)

Compression molding

Composites

Artificial combinations ofmaterials

Composite materials

wPolymer-matrix composites

wCement-matrix composites

wMetal-matrix composites

wCarbon-matrix composites

wCeramic-matrix composites

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Composite materials

wParticulate

wFibrous (discontinuous fibers)

wFibrous (continuous fibers)

wLamellar

Cement-matrix composites

wCement paste

wMortar

wConcrete

Carbonsw

Graphitew Diamondw Fullerenes (buckminsterfullerenes)w Carbon nanotubesw Turbostraticcarbonw Diamond-like carbon (DLC)w Intercalation compounds of graphitew Exfoliated graphite (worms)w Flexible graphite

Structures

w Buildings, bridges, piers, highways,landfill cover

w Aircraft, satellites, missilesw Automobiles (body, bumper, shaft,

window, engine components, brake, etc.)w Bicycles, wheelchairsw Ships, submarinesw Machineryw Tennis rackets, fishing rods, skis

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Structures (continued)

w Pressure vessels, cargo

containersw Furniture

w Pipelines, utility poleswArmor, helmets

wUtensilsw Fasteners

wRepair materials

Multifunctionality in structures

w

Load bearingwAssembly and packaging

wVibration reduction (damping)

w Structural health monitoring(damage sensing)

w Structural vibration control

wModulus control

Multifunctionality instructures (continued)

w Self-sensing of strain, damage and temperature

w Building managementw Building security

w Thermal insulationw Self-heating (e.g., deicing)

w Self-healing

w Electromagnetic interference (EMI) shieldingw Low observability (Stealth)w Energy generation

Embedded or attacheddevices or materials

w Sensors (e.g., , strain gages, opticalfibers)

wActuators (e.g., electrostrictivematerials, magnetostrictive materials,shape-memory alloys, etc.)

wViscoelastic materials

wMagnetorheological materials

w Electrorheological materials

Disadvantages of embeddedor attached devices

wHigh cost

wPoor durability

wPoor repairability

wLimited functional volume

wDegradation of mechanicalproperties

Structural performance

w High strengthw High modulus (stiffness)w Mechanical fatigue resistancew Thermal fatigue resistancew Low densityw Corrosion resistancew Moisture resistancew Freeze-thaw durability

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Structural performance(continued)

w High temperature resistancew Thermal shock resistancew Low thermal expansion coefficientw Creep resistancew Low fluid permeabilityw Repairabilityw Maintainabilityw Processability

Electronic applications

wElectrical applicationswOptical applications

wMagnetic applications

Electrical applications

w Computersw Electronicsw Electrical circuitry (resistors, capacitors,

inductors)w Electronic devices (diodes, transistors)w Optoelectronic devices (solar cells, light

sensors, light-emitting diodes)w Thermoelectric devices (heaters, coolers,

thermocouples)

Electrical applications(continued)

w Piezoelectric devices (sensors, actuators)

w Roboticsw Micromachines (microelectromechanical

systems or MEMS)

w Ferroelectric computer memoriesw Electrical interconnections (solder joints, thick -

film conductors, thin-film conductors)w Dielectrics (electrical insulators in bulk, thick -

film and thin-film forms)

Electrical applications(continued)

w Substrates for thin films and thick films

w Heat sinksw Electromagnetic interference (EMI) shielding

w Cablesw Connectors

w Power suppliesw Electrical energy storage

w Motorsw Electrical contacts, brushes (sliding contacts)

Electrical applications(continued)

wElectrical power transmission

wEddy current inspection (use of amagnetically induced electricalcurrent to indicate flaws in amaterial)

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Optical applications

w Lasers

w Light sourcesw Optical fibers (materials of low optical absorptivityfor

communication and sensing)

w Absorbers, reflectors and transmittors ofelectromagnetic radiation

w Photography

w Photocopying

w Optical data storage

w Holography

Magnetic applications

w TransformerswMagnetic recording (data storage)

wMagnetic computer memories

wMagnetic field sensors

wMagnetic shielding

wMagnetically levitated trains

Magnetic applications(continued)

w Roboticsw Micromachinesw Magnetic particle inspectionw Magnetic energy storagew Magnetostrictionw Magnetorheological fluidsw Magnetic resonance imaging (MRI, for

patient diagnosis)w Mass spectrometry (for chemical analysis)

Electronic packaging

w Electrical interconnectionsw Chip carriersw Interlayer dielectricsw Encapsulationsw Heat sinksw Thermal interface materialsw Housingsw EMI shielding

Thermal applications

wHeating and cooling of buildingsw Industrial heating (casting, annealing,

deicing, etc.)wRefrigeration

wMicroelectronic coolingwHeat removal (brakes, cutting,

welding, chemical reactions, etc.)

Mechanisms of heattransfer

w Conduction (by electrons, ions orphonons)

w Convection (by hot fluid, whether forcedor natural convection)

w Radiation (black-body radiation,particularly infrared radiation, for spaceheaters)

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Materials for thermalapplications

wThermal conductorswThermal insulators

wHeat retention materials (highheat capacity)

wThermal interface materials

wThermoelectric materials

Electrochemicalreaction

wAnodewCathode

wElectrolyte

wCatalyst (optional)

Electrochemicalapplications

wBatteries

wFuel cells (galvanic cells in whichthe reactants are continuouslysupplied, e.g., the hydrogen-

oxygen fuel cell)

Environmentalprotection

w Pollutant removal (e.g., filtration,absorption by activated carbon)

wReduction in the amount of pollutantgenerated (e.g., use of biodegradablepolymers)

wRecyclingw Electronic pollution control

Biomedical applications

wDiagnosis

wTreatment

wScope: conditions, diseases,disabilities, and their prevention

Biomedical materials anddevices

w Implantsw Bone replacement materials

w Bone growth support

w Surgical and diagnostic devicesw Pacemaker

w Electrodes for collecting or sendingelectrical or optical signals

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Biomedical materials anddevices (continued)

wWheelchairswDevices for helping the disabled

wExercise equipment

wPharmaceutical packaging

wInstrumentation

Requirements of implantmaterials

wBiocompatiblewCorrosion resistant

wWear resistant

wFatigue resistant

wDurability for tens of years

A biomedical compositematerial

wParticulate composite

wCeramic particles:hydroxyapatite + tricalciumphosphate

wPolymer matrix: collagen

Desirable qualities of anadsorption material

w Large adsorption capacity

w Pores accessible from the outside

w Pore size large enough for relatively largemolecules or ions to lodge

w Ability to be regenerated or cleaned after use

w Fluid dynamics for fast movement of the fluid

w Selective adsorption of certain species

Pore size nomenclature

wMacropores (exceeds 500 )

wMesopores (between 20 and 500 )

wMicropores (between 8 and 20 )

wMicromicropores (less than 8 )

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Functions of filtermaterials

wMolecule or ion removal(by adsorption)

wParticle removal