Local Piezoelectric Response andLocal Piezoelectric Response andElastic Properties asElastic Properties asMeasured with AFMMeasured with AFM

Emily SmithEmily Smith

eas48@drexel.edueas48@drexel.edu

Advisor: Dr. SpanierAdvisor: Dr. Spanier

Problem StatementProblem Statement

Techniques to measure local properties of Techniques to measure local properties of bonebone

Correlation with hierarchical structuresCorrelation with hierarchical structures

Piezoelectricity connection with bone Piezoelectricity connection with bone growthgrowth

What is Bone?What is Bone?

CollagenCollagen

ProteinProtein

Hydroxyapatite Hydroxyapatite

Ca-phosphate mineralCa-phosphate mineral

TypesTypes– CorticalCortical– CancellousCancellous

http://silver.neep.wisc.edu/~lakes/BME601.html

BoneBoneHierarchical StructureHierarchical Structure

Rho, Jae-Young, Liisa Kuhn-Spearing and Peter Zioupos. Mechanical properties and the hierarchical structure of bone. Mechanical Engineering & Physics. 20 (1998) 92-102.

Bone CellsBone Cells

OsteoOsteoclastsclasts– Breaks down and Breaks down and

removes bone materialremoves bone material

OsteoOsteoblastsblasts– Forms new bone Forms new bone

materialmaterial

OsteoOsteocytescytes– Senses problems and Senses problems and

pressure in the bonepressure in the bone

http://depts.washington.edu/bonebio/bonAbout/bonecells.html

nucleus

Multiple Nuclei

Microscope Image of Bone CellsMicroscope Image of Bone Cells

http://depts.washington.edu/bonebio/bonAbout/bonecells.html

Principle of AFMPrinciple of AFM

http://www.npl.co.uk/smd/npl_research/afm_theory.html

Atomic Force MicroscopyAtomic Force Microscopy

Scan probe microscopyScan probe microscopy

Three Topographic Three Topographic ModesModes– ContactContact– AC Intermittent AC Intermittent – AC Non-contactAC Non-contact

www.asylumresearch.com

Force vs. Tip-Sample SeparationForce vs. Tip-Sample Separation

C- Contact

IC – Intermittent Contact

NC – Non-contact

Catalin Harnagea. Local piezoelectric response and domain structures in ferroelectric Catalin Harnagea. Local piezoelectric response and domain structures in ferroelectric thin films investigated by voltage-modulated force microscopy. Ph.D. thesis. 2001thin films investigated by voltage-modulated force microscopy. Ph.D. thesis. 2001

PiezoelectricityPiezoelectricity

PiezoelectricPiezoelectric– Mechanical Stress => Electric FieldMechanical Stress => Electric Field

Equation: D = d * Equation: D = d * σσ

– Converse Piezoelectric EffectConverse Piezoelectric EffectEquation: x = d * EEquation: x = d * E

FerroelectricFerroelectric– Spontaneous Dipole MomentSpontaneous Dipole Moment– DomainsDomains

ElasticityElasticity

Ratio of stress and strainRatio of stress and strain

Ability to return to its original shapeAbility to return to its original shape

Current ways to measureCurrent ways to measure

Strain

Str

ess

Elastic Range

Strength

http://hotmix.ce.washington.edu/wsdot_web/Modules/04_design_parameters/04-2_body.htm#elastic_modulus

Piezoresponse Scan PrinciplePiezoresponse Scan Principle

AC voltage AC voltage

Conductive Conductive TipTip

Contact Contact ModeMode

Scan of Sample: Scan of Sample: Lamella of Cortical BoneLamella of Cortical Bone

Line cross-section of scan:

Shows height

Single Lamella

Rho, Jae-Young, Liisa Kuhn-Spearing and Peter Zioupos. Mechanical properties and the hierarchical structure of bone. Mechanical Engineering & Physics. 20 (1998) 92-102.

Example of Piezoresponse ScanExample of Piezoresponse Scan

a- Topographic

image of a

Bi4Ti3O12 grain

(line added)

b- The domain

structure

Catalin Harnagea. Local piezoelectric response and domain structures in ferroelectric Catalin Harnagea. Local piezoelectric response and domain structures in ferroelectric thin films investigated by voltage-modulated force microscopy. Ph.D. thesis. 2001thin films investigated by voltage-modulated force microscopy. Ph.D. thesis. 2001

Piezoelectric Response in BonePiezoelectric Response in Bone

(a) Topography

(b)/(c) Piezoresponse Scan

C. Halperin, S. Mutchnik, A. Agronin, M. Molotskii, P. Urenski, M. Salai, and G. Rosenman. Piezoelectric Effect in Human Bones Studied in Nanometer Scale. Nano Letters. 4 (2004) 1253-6.

Future WorkFuture Work

Piezoelectric Response Piezoelectric Response

Piezoelectric coefficientPiezoelectric coefficient

Elasticity measurementElasticity measurement

LiteratureLiterature

Jae-Young Rho, Liisa Kuhn-Spearing and Peter Zioupos. Jae-Young Rho, Liisa Kuhn-Spearing and Peter Zioupos. Mechanical properties and the hierarchical structure of bone. Mechanical properties and the hierarchical structure of bone. Mechanical Engineering & Physics. 20 (1998) 92-102. Mechanical Engineering & Physics. 20 (1998) 92-102. Catalin Harnagea. Local piezoelectric response and domain Catalin Harnagea. Local piezoelectric response and domain structures in ferroelectric thin films investigated by voltage-structures in ferroelectric thin films investigated by voltage-modulated force microscopy. Ph.D. thesis. 2001modulated force microscopy. Ph.D. thesis. 2001C. Halperin, S. Mutchnik, A. Agronin, M. Molotskii, P. Urenski, M. Salai, and G. Rosenman. Piezoelectric Effect in Human Bones Studied in Nanometer Scale. Nano Letters. 4 (2004) 1253-6.http://silver.neep.wisc.edu/~lakes/BME601.htmlhttp://depts.washington.edu/bonebio/bonAbout/bonecells.htmlhttp://www.npl.co.uk/smd/npl_research/afm_theory.htmlwww.asylumresearch.comhttp://hotmix.ce.washington.edu/wsdot_web/Modules/04_design_parameters/04-2_body.htm#elastic_modulus