Specialty metals have been a vital part of the medical industry, specifically in the development of medical devices. From basic diagnostic guide wires to sophisticated body implants, these metals keep growing their list of medical uses through the years.
Stainless SteelStainless Steel
Stainless steel has been the champion of the medical device market through the last decades. Obviously, it is the top alloy of choice of most design engineers, thanks to its low cost, wide variety of forms and finishes, and corrosion-resistant properties.
Titanium is another popular and highly versatile metal used to make medical devices. As stainless steel, it resists corrosion and attaches to human bone with minimal adverse reactions. The process that allows natural bone and tissue to fully attach to a titanium implant is known as 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. 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 a popular choice for more than 40 years in the manufacture of diagnostic marker bands, as a catheter plastic compounding additive, and for many other medical applications. 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. 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 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.