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1. AuxeticsAuxetics

2. What Are Their Characteristics?What Are Their Characteristics?
 Auxetic materials areAuxetic materials are
any material thatany material that
thickens whenthickens when
stretched and Thinsstretched and Thins
when compressed.when compressed.
 Known as “a negativeKnown as “a negative
Poisson’s Ratio, ”Poisson’s Ratio, ”
 They have both highThey have both high
energy absorption andenergy absorption and
fracture resistance.fracture resistance.
 Low density to allowLow density to allow
for the pinched areasfor the pinched areas
1
V

3. Natural OccurringNatural Occurring
 single-crystal arsenicsingle-crystal arsenic
 catskincatskin
 load-bearing cancellous bone fromload-bearing cancellous bone from
human shinshuman shins

4. Current UsesCurrent Uses
 Pyrolytic graphite for thermalPyrolytic graphite for thermal
protection in aerospace applications.protection in aerospace applications.
 Ni3Al in vanes for aircraft gasNi3Al in vanes for aircraft gas
turbine engines.turbine engines.
 Expanded form of PTFE used to makeExpanded form of PTFE used to make
Gore-Tex.Gore-Tex.
 Foam mopsFoam mops

5. Continued Current UsesContinued Current Uses
 polymeric and metallic foamspolymeric and metallic foams
 carbon fibre composite laminatescarbon fibre composite laminates
 microporous polymersmicroporous polymers

6. Possible UsesPossible Uses
 Biomedical-Biomedical-
Prosthetic materials, surgical implants,Prosthetic materials, surgical implants,
suture/muscle/ligament anchors andsuture/muscle/ligament anchors and
a dilator.a dilator.
 Filters-Filters-
Any foam or honeycomb filter is aAny foam or honeycomb filter is a
possibility.possibility.
 Fibers-Fibers-
Bullet proof vests.Bullet proof vests.