Specialty metals have long played a vital role in the medical industry, particularly in medical device manufacturing. From diagnostic guide wires to permanent body implants, these metals continue to prove their use in more and more ways.
Stainless SteelStainless Steel
Stainless steel has been the champion of the medical device market through the last decades. Clearly, most design engineers look to it as their alloy of choice, thanks to its long list of advantages, such as variety of form and finishes, corrosion resistance, and affordability.
Another highly versatile metal popularly used in making medical devices is titanium. 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.
In recent years, there has been a growing interest in niobium and its alloys in the medical device manufacturing community. Because of the metal’s inertness, it is usually used to make pacemakers and others related devices. When treated with sodium hydroxide, niobium creates a porous layer that promotes osseointegration, making it a good alternative 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 a nickel-titanium shape memory alloy (around 51% Ni) that has superelastic properties when subjected to applied stress. Shape memory refers to the metal’s ability to deform and recover its original shape when heated above its transformation temperature. This extraordinary property of nitinol, on top of its being chemically and physiologically compatible with the human body, makes it a favorite among medical device engineers and designers.
Lastly, the medical industry seems to have adjusted its position on copper and is actually funding more and more research to look into the metal and its allows. Copper was once off limits for most medical purposes, considering its thrombogenic (bleeding) risks, but now, it has grown a new fanbase 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 make copper products for medical uses generally have their own equipment for metal wire/strip shielding, so as to ensure excellent quality and prevention of cross-contamination.