II.
                                                               Spinoff Prosthetics
What are prosthetics?
    Most people are lucky enough to have all of their fingers, toes, arms, and legs intact.
However, some people live their lives without the benefit of one or more parts of their body.
They might have been born this way, injured in an accident, or survivors of a disease. Although
ordinary tasks become more challenging for them, they are often able to regain many of the
functions of missing body parts through the use of prosthetics. Prosthetics are artificial,
substitute body parts.
The History of Prosthetics
    Prosthetics have been around for a very long time. Scientist recently discovered a
working prosthetic toe on a 3,000-year-old Egyptian mummy. In a similar case, an artificial leg
was found in a Roman grave in Capua, Italy. This false leg dates back to 300 B.C. In fact, for
centuries, humans have successfully created devices to replace missing body parts. However,
one challenge with prosthetics has been finding the right materials to manufacture them.
Prosthetics made of wood, metal, or plastic have been heavy, which has limited their
functionality.
Materials of Prosthetics
    A variety of metals are used for prosthetics limbs； Aluminum, Titanium, Magnesium,
Copper, Steel, and many more. They are each used in a varied amount and for various
applications, either pure or alloyed. Copper, iron, aluminum and nickel have all been used for
the load bearing structure in the past, but are currently used primarily as alloys or for plating.
Doctors and engineers work together to find the best design and material to make the best piece
for the patient. To create a life-like appearance, a foam cover can be applied and shaped to
match the real limb. A flexible skin-like covering will be applied over the foam to give it the
life-like appearance. The material for each piece is carefully selected based on the users’
environment and needs in conjunction with the material’s properties. Pure metals and metal
alloys have replaced the wooded materials of the past for the main load bearing structure.
Carbon fibers and polymers have replaced leather straps and the supporting components.
Spinoff Innovations
    Thanks to NASA’s research, Harshberger Prosthetics, Inc. has made prosthetics lighter
and more durable. According to president and owner Jerald J. Harshberger, the company wanted
to improve their prosthetics and analyzed the materials they were using. Their previous products
were heavy and easily broken. Then someone suggested that Harshberger try the materials
NASA uses to cover and protect the space shuttle’s fuel tanks from cold temperatures in outer
space. The covering was known to be strong, light, and more affordable than what they were
already using. Harshberger modified the company’s prosthetic materials and it worked! Now
their sales have increased because of the superior product. Harshberger prosthetics is an
excellent example of spinoff technology being put to very good use.
【題組】41. Who needs prosthetics? would be placed under the outline heading:
(A) What are prosthetics?
(B) The History of Prosthetics
(C) Materials of Prosthetics
(D) Spinoff Innovations