Syllabus - Chapters

STRUCTURE OF BIO-MATERIALS AND BIO-
COMPATIBILITY

IMPLANT MATERIALS

POLYMERIC IMPLANT MATERIALS

TISSUE REPLACEMENT IMPLANTS

ARTIFICIAL ORGANS

STRUCTURE OF BIO-MATERIALS AND
BIO-COMPATIBILITY

Definition and classification of bio-materials

Mechanical properties, visco elasticity

Wound-healing process,

Body response to implants, Blood compatibility.

Definition

A biomaterial is a synthetic material used to replace part of a living system or to function in intimate contact with living tissue

Commonplace examples include sutures, needles, catheters, plates, tooth fillings, etc

Classification of bio-materials

From the point of view of the problem area which is to be solved

By considering the levels of organisation

Classification based on materials

Mechanical properties

The behavior of the material under loading

Two important properties

STRENGTH

STIFFNESS

The load - deformation curve

Determinants of strength

The load that the structure can sustain before failing

Ultimate failure point

The deformation it can sustain before failing

Slope of the curve - Stiffness

The stress – strain curve
(In tension)


Stress σ


Strain ε
Young ’ s modulus E = σ / ε

Elasticity of a material

A comparison

Mechanical properties of biomaterials

Visco elasticity

Viscoelasticity

The material is subjected to Constant load and its response varies with time

Combination of viscous fluid and elastic solid

Two fundamental responses

Creep

Stress relaxation

Creep & Stress relaxation

Constant load → rapid initial deformation → slow (time-dependent) progressively increasing deformation → till equilibrium is reached

Constant deformation → rapid initial stress → slow (time-dependent) progressively decreasing stress