BIO-MATERIALSBIO-MATERIALS

STRUCTURE OF BIO-MATERIALS AND BIO-STRUCTURE OF BIO-MATERIALS AND BIO-COMPATIBILITYCOMPATIBILITY

IMPLANT MATERIALSIMPLANT MATERIALS

POLYMERIC IMPLANT MATERIALSPOLYMERIC IMPLANT MATERIALS

TISSUE REPLACEMENT IMPLANTSTISSUE REPLACEMENT IMPLANTS

ARTIFICIAL ORGANSARTIFICIAL ORGANS

Syllabus - ChaptersSyllabus - Chapters

STRUCTURE OF BIO-MATERIALS STRUCTURE OF BIO-MATERIALS AND BIO-COMPATIBILITYAND BIO-COMPATIBILITY

Definition and classification of bio-Definition and classification of bio-materialsmaterials

Mechanical properties, visco Mechanical properties, visco elasticityelasticity

Wound-healing process, Wound-healing process, Body response to implants, Blood Body response to implants, Blood

compatibility.compatibility.

DefinitionDefinition

A biomaterial is a synthetic material A biomaterial is a synthetic material used to replace part of a living used to replace part of a living system or to function in intimate system or to function in intimate contact with living tissuecontact with living tissue

Commonplace examples include Commonplace examples include sutures, needles, catheters, plates, sutures, needles, catheters, plates, tooth fillings, etctooth fillings, etc

Classification of bio-Classification of bio-materialsmaterials

From the point of view of the From the point of view of the problem area which is to be solvedproblem area which is to be solved

By considering the levels of By considering the levels of organisationorganisation

Classification based on Classification based on materialsmaterials

Mechanical properties Mechanical properties

The behavior of the material under The behavior of the material under loadingloading

Two important propertiesTwo important properties STRENGTHSTRENGTH STIFFNESSSTIFFNESS

The load - deformation The load - deformation curvecurve

Determinants of strengthDeterminants of strength

The load that the structure can The load that the structure can sustain before failing sustain before failing Ultimate failure pointUltimate failure point

The deformation it can sustain The deformation it can sustain before failingbefore failing Slope of the curve - Stiffness Slope of the curve - Stiffness

The stress – strain curveThe stress – strain curve(In tension)

Stress Stress σσ Strain Strain εε Young’s modulus E = Young’s modulus E = σσ / / εε

Elasticity of a materialElasticity of a material

A comparisonA comparison

Mechanical properties of Mechanical properties of biomaterialsbiomaterials

Visco elasticity Visco elasticity

ViscoelasticityViscoelasticity

The material is subjected to Constant The material is subjected to Constant load and its response varies with timeload and its response varies with time

Combination of viscous fluid and Combination of viscous fluid and elastic solidelastic solid

Two fundamental responsesTwo fundamental responses CreepCreep Stress relaxationStress relaxation

Creep & Stress relaxationCreep & Stress relaxation

Constant load → rapid initial Constant load → rapid initial deformation → slow (time-deformation → slow (time-dependent) progressively increasing dependent) progressively increasing deformation → till equilibrium is deformation → till equilibrium is reachedreached

Constant deformation → rapid initial Constant deformation → rapid initial stress → slow (time-dependent) stress → slow (time-dependent) progressively decreasing stress progressively decreasing stress