Biomaterials Quiz

Biomaterial [Old]

Biomaterial [Old]

a non-viable material used in a medical device intended to interact with biological systems

Biomaterial [New]

Any material used to make devices to replace a part or a \n function of the body in a safe, reliable, economic, and physiologically acceptable manner.

Synthetic Materials

Metals, polymers, ceramics, composites

Biological Materials

Biopolymers, tissue derived (collagen), tissues

Joint replacements, plates, screws

Titanium, titanium alloys, cobalt-chromium, allografts

Bone replacement/regeneration

Hydroxyapatite, stem cell

Biomaterials outside of medical devices

Biosensors, microfluids, nanofabrication, neural computing

Biomaterials must be…

Biocompatible

Structural properties

Stiffness, area/mass, moment of inertia

Material properties

Elastic modulus, viscoelasticity, fatigue life

Biocompatibility

Acceptance of an artificial implant by the \n surrounding tissues and by the body as a \n whole (doesn’t degrade or degrades without harm)

Biomaterial Selection Criteria

• Biocompatibility

• Physical & mechanical properties

• Biological fixation properties

• Easy to make and sterilize

  • Can function in vivo

Device Performance

• Design

• Structural requirements

• Clinical requirements

• Regulatory (FDA)

• Processing

  • Materials selection

Bulk Properties

• Tension/compression

• Shear/torsion

• Bending

• Hardness

Surface Properties

• Surface roughness

• Surface crystallinity

• Surface energy (hydrophilicity)

Stress

Force / Area

Strain

Change in length / Original Length

Hooke’s Law

Stress = Modulus * Strain

What does Poisson’s ratio measure?

Resistance to volume change (lateral strain over longitudinal strain)