Today, medical device contract manufacturing is a booming industry. Medical equipment is made of specific metals to ensure that the equipment will work properly for a long time without the risk of corrosion or being affected by the surrounding environment, as this may affect the recovery of the patient.
If you are a developer of medical products or other equipment used in the healthcare environment, you need to choose the materials of manufacture carefully. Generally, for applications requiring the highest strength and durability, metal is usually chosen over plastic or other materials, especially when used for tools that withstand great mechanical stress or as replacement joints.
Moreover, in addition to purely mechanical properties, metals used in medical environments must also meet specific standards that most other products cannot meet. For example, in the presence of human tissues or body fluids, they may need to be non-toxic. Or, they may have to resist cleaning chemicals, such as detergents and alcohol. In addition to being non-toxic, the metal used for implants must also be non-magnetic and non-corrosive.
Understanding the differences between these materials and the many possibilities offered by each metal provides designers with a certain degree of freedom in choosing the appropriate grade or alloy for the application. Manufacturers of medical devices and implantable devices today can choose from a variety of effective metals.
In this article, we will study which materials are suitable for manufacturing medical devices. Several common metals and metal alloys have become indispensable.
Stainless Steel
When giving instructions to integrate metal parts into a medical device design, the usual choice is one of the 300 series stainless steel.
These alloys are actually non-corrosive. Various surface finishes can be manufactured, from reflective to matt; it provides excellent mechanical and physical properties; and it is easier to cold form or process into different parts.
The stainless steel alloy is composed of 17% to 25% chromium and 8% to 25% nickel. The presence of chromium provides some corrosion resistance of stainless steel by forming a research, adhesive and invisible chromium oxide film on the surface of the alloy.
Stainless steel is an ideal material for many types of medical devices. It is non-toxic, non-corrosive, durable, and can be polished to a very fine surface for easy cleaning.
The most common types of stainless steel used for medical implants and body piercings are 316 and 316L, which have high corrosion resistance. This is important because corrosion in the blood can cause infection and possibly even death. Many people also have allergic reactions to nickel. Therefore, it can replace low-nickel stainless steel varieties.
Most surgical tools are made of 440 stainless steel. It is not as corrosion resistant as 316, but has a higher carbon content, which means it can be heat treated to create very sharp edges for cutting tools.
It can also be used for tweezers, tweezers, hemostats and other surgical tools, which must be durable and easy to clean and disinfect. Also, stainless steel mesh is sometimes used for intravascular stents.
Titanium
Among the commonly used metal materials, titanium is one of the most popular metals used in the manufacture of medical devices. In addition to medical equipment for internal use, it is also used to manufacture equipment for external use, such as surgical instruments, dental equipment, and orthopedic equipment. Pure titanium is the most inert and the most expensive-usually used for ultra-high reliability parts or parts left on the patient after surgery. Titanium is now a common substitute for stainless steel and can be used to make bone supports and bone substitutes. It is as strong and durable as stainless steel, at the same time lighter in weight, and has excellent biocompatibility. These include replacement joints, pacemaker cans and other metal implants.
There are medical grade titanium alloys specifically used to manufacture medical devices. Titanium 6AL4V ELI and Titanium 6AL4V are alloys composed of 4% vanadium and 6% aluminum. Titanium alloy is harmoniously combined with the human body, so it is very suitable for medical device manufacturing. It is not surprising that titanium alloys can also be made into many perforations.
Other types of titanium used in medical devices include Gr.23 and Gr.5, which are special grades used by specific medical device manufacturers. Ti-6AL-4V ELI and Ti-6AL-4V are commonly used in the manufacture of dental implants and dental equipment, mainly because of their high fracture resistance.
Copper titanium is also resistant to bacteria and is ideal for surgical equipment, because if exposed to bacteria, there is no need to worry about contamination, and it can be used safely with equipment that emits radiation
Aluminum
Although it rarely comes into direct contact with the body, aluminum is very commonly used for various types of support equipment, which must be light, strong, and corrosion-resistant. Examples include bed frames, wheelchairs, walking sticks, orthopedic stents and intravenous stents. Because raw aluminum is easy to rust or oxidize, aluminum parts usually need to be painted or anodized to improve durability.
Niobium
Niobium is one of the refractory special metals used in medical equipment today. Niobium is highly inert and biocompatible. In addition to its valuable properties such as high thermal conductivity and high electrical conductivity, it is often used to make small parts of pacemakers. Tantalum is a highly porous refractory metal that promotes bone growth and adheres to it, so that tantalum can be used for implants in the presence of bone. This material is also used for diagnostic marker tapes. However, due to the cost and rarity of the element, tantalum is often used as a composite material.
Tungsten
Tungsten is also often part of medical equipment, such as tubes used to perform minimally invasive laparoscopy and endoscopy procedures. In addition to providing mechanical strength, tungsten can also be used where radiopacity is required, mainly in fluorescence inspection applications, and the density of tungsten is greater than that of lead, and it can also be used as an environmentally harmless lead substitute for radiation shielding materials.
Nitinol
Nitinol is an alloy made from a combination of nickel and titanium. This metal responds in a reversible manner when stress is applied due to its superelastic properties. Shape memory is a term used to express the ability of Nitinol to undergo deformation at a certain temperature, and then to recover its original shape when exposed to a temperature above its transformation temperature.
Due to its ability to withstand large strains, Nitinol is widely used as an ideal material for medical equipment design and engineering. Some medical devices made using this metal include tools such as biopsy devices and small grasping tools. Ideal for manufacturing medical tools that can be easily expanded and expanded to a large area.
Due to its unique performance and light weight characteristics, Nitinol is very suitable for manufacturing biomedical applications, such as staples, heart valve tools, complex spacer devices, bone anchors, heart valve devices, and various implants.
It can also be used to make localizable markers and diagnostic lines for breast tumor localization. These devices are preferred because they are less invasive in the diagnosis and treatment of breast cancer.