by Medical elastomers are synthetic polymers that are elastic or rubber-like in nature. They have unique properties that make them ideally suited for use in medical devices and healthcare applications. Some key properties of medical elastomers include flexibility, durability, biocompatibility and permeability to gases.
Silicone Elastomers
Silicone elastomers are one of the most widely used types of Medical Elastomers. They offer excellent biocompatibility, flexibility over a wide temperature range and high purity. Silicone exhibits low toxicity and does not elicit an immune response in the body. For this reason, it is often the material of choice for long-term implantable devices. Some common medical applications of silicone elastomers include:
– Pacemaker leads and connectors: Silicone provides flexibility needed for leads to flex with heartbeats without fatigue. It also protects electronic components from body fluids.
– Breast implants: Silicone gel or saline filled implants rely on an outer silicone elastomer shell that is flexible yet durable enough to maintain shape over years.
– Catheters: Both urinary and vascular catheters use silicone tubing for its flexibility, kink resistance and biocompatibility.
– Orthopedic devices: Silicone elastomer formulations are used for braces, tendon replacement parts and finger joints prosthetics.
– Seals and gaskets: Medical devices often require silicone o-rings, seals or gaskets to protect components and attain proper instrument functioning.
Polyurethane Elastomers
Polyurethane elastomers represent an important class of medical thermoplastic elastomers. They can be formulated with a wide range of hardnesses and possess good mechanical properties. As such, they find applications where silicone is not an optimal material choice. Examples include:
– Pacemaker connector seals and lids: Hard yet flexible polyurethane used where durability is critical.
– IV tubing and connectors: Polyurethane offers kink resistance and flexibility comparable to PVC but without plasticizer migration issues.
– Orthopedic devices: Formulated for strength and load bearing, used in artificial knees, shoulders and other joint replacements.
– Catheters: Balloons for angioplasty and other procedures rely on polyurethane for its inflation characteristics.
– Heart valves: Recent innovations use polyurethane heart valves offering durability with hemodynamic performance.
Other Important Elastomer Types
While silicone and thermoplastic polyurethane are most widely established, other elastomer types also play a role:
– Thermoplastic elastomers (TPEs): Offer processing advantages for certain devices, used in wound drainage tubes and connectors.
– Fluoroelastomers: Chemical resistance properties used in corrosive biological and pharmaceutical applications.
– Hydrogels: Certain hydrogel formulations exhibit elastomeric properties for applications such as contact lenses and wound care dressings.
– Latex: Natural rubber still used for examination and surgical gloves requiring a delicate tactile feel. However, concerns over allergies limit broader medical use.
Material Selection Considerations
Choosing the right elastomer type and formulation depends on several application-specific factors:
– Design requirements: Flexibility, compression set, tensile strength etc. needed for the device function.
– Manufacturing process: Injection molding, extrusion or other process compatibility with the elastomer.
– Biocompatibility: Cytotoxicity, sensitization potential, USP class VI certification etc.
– Regulatory compliance: Material must meet strict requirements of FDA, EU or other regulations.
– Shelf life and stability: Resistance to aging, chemicals, UV light, heat etc. over intended lifetime.
– Cost: Often polyurethanes and TPEs offer lower cost options compared to silicones for certain applications.
Working closely with an elastomer supplier is important to evaluate and select the material best matched to technical and regulatory performance needs of new medical device designs.
In summary, medical elastomers have become indispensable engineered materials that enable manufacturing of life-enhancing modern medical technologies. Continued research and innovation will lead to new elastomer formulations optimized for emerging applications involving drug delivery mechanisms, soft robotics and degradable implants. With stringent controls over purity, curing and processing of elastomers, the medical industry ensures they will remain safe, high performance materials supporting healthcare well into the future.
