Specialty metals have a long history with the medical industry, particularly in medical device development. From the most basic diagnostic guide wires to the most advanced body implants, these metals are unstoppable in proving themselves medically useful.
Stainless SteelStainless Steel
Through the years, stainless steel has been the most widely used metal in the medical device industry. It is obviously the alloy of choice for most design engineers, who know all of its benefits, including corrosion resistance, variety of forms and finishes, and low cost.
The highly versatile titanium is another top choice of medical manufacturers. Like stainless steel, it is corrosion-resistant and causes less negative reactions when connected to human bone, compared to other metals. Natural bone and tissue attaches to a titanium in a process called osseointegration. It is a staple in the medical manufacturing business as it is used to make a huge variety of products, from neurostimulation instruments to orthopedic rods, pins and plates, and of course, heart implants.
Medical device manufacturers have shown considerable and interest in niobium in the last few years. The metal’s inertness makes it a common choice for making pacemakers and other devices similar. Niobium treated with sodium hydroide is a suitable alternative for internal medical applications, as the process allows the metal to form a porous layer which aids osseointegration.
Tantalum has been used for more than 40 years in the medical device industry, expecially in making diagnostic marker bands and as a catheter plastic compounding additive. It is also highly useful in shaped-wire applications, such as implants, because of its ductility and corrosion-resistant properties. It is also known for being easy to weld and having good dielectric properties.
Nitinol is an alloy made of nickel and titanium (around 51% Ni) and can be superelastic when under applied stress. Shape memory gives the metal the ability to return to its original shape when heated over its transformation temperature. With its ability to manage large strains, along with its physiological and chemical compatibility with the human body, nitinol has become a preferred material for medical device engineers and designers.
Finally, in recent years, the medical industry appears to have changed its perspective on copper, even conducting more and more research into the metal and its alloys. Copper used to be off limits for most medical uses because of its thrombogenic (bleeding) risks, but it has developed a new following in the device community. What’s responsible for this change is the fact that with proper shielding, the metal can be an effective transmitter of signals to small implants and diagnostic tools. Companies that manufacture and process copper for medical devices generally have their own dedicated equipment for shielding of the metal wire or strips, if only to guarantee superior quality and eliminate all chances of cross-contamination.