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A D V A N C E D M A T E R I A L S & P R O C E S S E S | J U L Y / A U G U S T 2 0 1 6
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research is to understand and compare
the mechanical properties of synthetic
materials to native tissues. While ASTM
and ISO standards are forming to help
guide biomaterials test-
ing, most testing regi-
mens performed in both
industry and academia
are created internally.
As biomaterials exhibit
viscoelastic properties,
there is often a simple
cyclic component to a
static tensile test.
Biomaterials test-
ing is often conducted
at body temperature
and in a saline bath to
best mimic physiolog-
ical conditions. Other
knee injuries, such as
patellofemoral syn-
drome, are caused by
the knee cap repeatedly
moving against the leg
bone and wearing out
or damaging knee cap
tissues. This is often
evident in athletes who
run, swim, play basket-
ball, and cycle.
Biomaterials, such as hydrogels,
may someday help treat wear and
damage to knee cap tissues. Hydro-
gel stiffness can vary by increasing or
decreasing the number of crosslinks in
the polymer. Many materials scientists
perform rheology, compression, ten-
sion, and fatigue testing on hydrogels
to understand mechanical properties
during and after polymerization, as well
as long-term properties. Although mus-
cle, ligament, and tendon tears along
with cartilage wear are fairly com-
mon in both professional and recre-
ational athletes, biomaterial solutions
are still in the research and develop-
ment phase due to the complexity of
biocompatibility.
In the clinical setting, materials
scientists already have solutions to
deal with broken bones—bone screws
and fracture fixation plates are widely
used and are biocompatible. When a
severe bone fracture occurs, sometimes
a cast is insufficient to heal the break.
Commonly, a titanium plate with bone
screws used to hold the plate in place
will bridge two or more fractured bone
pieces together.
While these are metal implants
and not biomaterials, by using a type
of metal with mechanical properties
similar to bone, scientists have discov-
ered that bone will integrate with these
plates. The integration of bone with a
fracture fixation plate and bone screws
is known as osseointegration. Once the
metal fixation plate is in the body, it can
remain there indefinitely.
Mechanical testing is critical to
optimize the performance of sports and
recreation equipment and the materi-
als used to heal injuries resulting from
these activities. As scientists continue
to study the biomechanics of athletes
and continue to develop new materi-
als, lighter, stronger, and more flexible
sporting equipment will become avail-
able to both professional and recre-
ational athletes. ~AM&P
For more information: Elayne Gor-
donov is biomedical assistant mar-
ket manager, Instron, 825 University
Ave., Norwood, MA 02062-2643,
800.877.6674, .
Tensile testing of a biomaterial determines strength and elasticity properties.
1059LK_3.25x4.875_MetalBonding_40yr.indd 1 3/21/16 7:07 PM