Specialty metals have been a vital part of the medical industry, specifically in the development of medical devices. 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. As stainless steel, it resists corrosion and attaches to human bone with minimal adverse reactions. Natural bone and tissue attaches to a titanium in a process called osseointegration. The metal is one of the staples of the medical device industry, and is commonly used to make a wide range of products, from heart implants to orthopedic rods, pins and plates.
Medical device manufacturers have shown considerable and interest in niobium in the last few years. Because of the metal’s inertness, it is usually used to make pacemakers and others related devices. Treating niobium with sodium hydroxide gives it a porous layer that helps in the osseointegration process, making the metal a good option for internal medical applications.
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. Its corrosion resistance and high ductility make it a great choice for wire-shaped applications, such as implants. It is also preferred for its good dielectric properties, as well as for being easy to weld.
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. Nitinol’s ability to withstand large strains, besides the fact that it is physiologically and chemically compatible with the human body, has made it one of the most sought after materials for medical device designers and engineers.
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. Because of its thrombogenic (bleeding) risks, copper was once banned for most medical purposes, but it has now grown quite a following among device manufacturers. The reason for this change is the fact that the metal, as long as it is properly shielded, can be a good carrier of signals to diagnostic tools and small implants. 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.