SLU biomaterials test 1

Biomaterial

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

Biocompatibility

the ability of a material to perform with the appropriate host response in a specific application

1st generation biomaterial

bioinertness, no body response

2nd generation biomaterial

bioactivity

3rd generation biomaterial

regenerate functional tissue, degradable

intrinsic properties

depend on composition, not microstructure

extrinsic properties

depend on microstructure

Surface tension

tension of the surface film of a liquid caused by the attraction of the particles in the surface layer by the bulk of the liquid, which tends to minimize surface area.

Shear testing

test materials with low yield strength such as soft polymers, solgels, and viscous fluids

isotropic

material where properties are the same in all directions

ansiotropic

material where properties are not the same in all directions

yield strength

stress at which material begins irreversible plastic deformation

resilience

measure of elastic energy that can be stored in a unit volume of stressed material, area under elastic region of curve

toughness

amount of energy per volume that a material can absorb before failure, area under entire curve

creep

elongation and failure from stress below yield strength but for a long time

fatigue

progressive and localized structural damage that occurs when material undergoes cyclic loading

surface properties

atoms and molecules that reside at the surface of a biomaterial have special reactivity and direct biological response.

interface

transition between two phases an infinetly thin separation plane

interphase

unique compostion phase between two other phases

roughness

measure of texture of a surface

wettability

extent a liquid will spread over a solid surface, measured by water contact angle

adhesive force

attraction of liquid molecules for a surface

ESCA

x-rays, photoelectric effect, under vacuum, allows atom type to be found from binding energies

SIMS

composition and concentration of ions, vacuum, measures mass of emitted ion, dynamic (high ions, metallic and ceramics) and static (low ion, low surface damage, large molecular fragments)

SEM

looks at structure not composition, high electron beam under vacuum, metal coating required, shows surface/ surface roughness

FTIR

looks at composition, measures bond vibration and gives information of chemistry and orientation of structures, easier to use for bulk properties than surface, ATR and IRAS are types

STM

has to be a metal, uses quantum tunneling to show electron density of surface at atom-scale,

AFM

subnanometer resolution, used on any surface, tip on flexible arm where arm movements are measured

polymers

long chain molecules comprised of large number of repeat monomer units

isotactic

all tactic isomers are aligned

syndiotactic

tactic isomers are alternating what side they are on

atactic

tactic isomers are arranged randomly