2007-09-19 22:47:00
Nanotechnology diamond ice coatings could improve knee prostheses and solar
cells
There is a huge demand for medical implants for almost every body part you
can think of. As we have reported here before, the market for medical implant
devices in the U.S. alone is estimated to be $23 billion per year and it is
expected to grow by about 10% annually for the next few years. Implantable
cardioverter defibrillators, cardiac resynchronization therapy devices,
pacemakers, tissue and spinal orthopedic implants, hip replacements, phakic
intraocular lenses and cosmetic implants will be among the top sellers. Current
medical implants, such as orthopedic implants and heart valves, are made of
titanium and stainless steel alloys, primarily because they are biocompatible.
Unfortunately, in many cases these metal alloys with a life span of 10-15 years
may wear out within the lifetime of the patient. With recent advances in
industrial synthesis of diamond and diamond-like carbon film bringing prices
down significantly, researchers are increasingly experimenting with diamond
coatings for medical implants. On the upside, the wear resistance of diamond is
dramatically superior to titanium and stainless steel. On the downside, because
it attracts coagulating proteins, its blood clotting response is slightly worse
than these materials and the possibility has been raised that nanostructured
surface features of diamond might abrade tissue. That's not something you
necessarily want to have in your artificial knee or hip joints (although some of
the currently used implant materials cause problems as well). Researchers have
now run simulations that show that thin layers of ice could persist on specially
treated diamond coatings at temperatures well above body temperature. The soft
and hydrophilic ice multilayers might enable diamond-coated medical devices that
reduce abrasion and are highly resistant to protein absorption.
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