MATERIALS
What is a self-lubricating liquid silicone rubber? This medical-grade material can solve manufacturing challenges and increase medical device performance.
F
rom well-established biocompatibility to robust performance characteristics, silicone offers medical device manufacturers a unique engineered material ideal for these applications. One type, self-lubricating liquid silicone rubbers (LSRs), provides an excellent medical-grade material that can solve manufacturing challenges and increase device performance. These elastomers contain a built-in lubricant that, over time, elutes to the molded part’s surface. For medical-grade LSRs, this lubricant offers many of the same properties as the elastomer, such as inertness or biocompatibility. In addition, the lubricant can be formulated so it won’t cause swelling when it contacts other silicone elastomers, a process that can create dimensional or even mechanical challenges.
Alex Santayana NuSil — a brand of Avantor
Self-lubricating LSRs are available with varying lubricant levels and can be formulated to meet regulatory guidelines for short- and long-term implant use. These formulations are available offthe-shelf but can also be customized for specific manufacturing or end-user needs. The characteristics of self-lubricating LSRs make them ideal for minimizing friction at component interfaces to enhance the performance of medical devices, including wearable devices. In addition to components like O-rings and connector gaskets, these elastomers are used in dynamic seals, slit valves, membrane septa and duck-bill valves. For example, a self-lubricating LSR can be used on a silicone septum in an insulin delivery device to protect the needle, improve reliability and enable consistent performance. The elastomers have also been used in needle-free injection ports to deliver cancer treatments and other life-saving therapies. In these applications, a self-lubricating LSR allows manifolds to move more consistently and smoothly than a typical LSR. What advantages do self-lubricating LSRs offer medical device designers? Reduce time and labor: These elastomers eliminate the need for an extra processing step, like dipping or spraying the component with a lubricant, saving assembly time. In addition, self-lubricating LSRs can improve assembly in applications where sliding components tend to bind.
From innovative new cancer therapies to pioneering diabetes care, selflubricating LSRs may be the right choice to efficiently manufacture medical devices that make a life-changing difference in patients’ lives.
Create more reliable performance: Because the lubrication elutes from within, the article’s surface is coated with an even amount of oil. This eliminates the potential for inconsistency that can stem from imprecise or uneven applications, such as undercut or shadowed features that are incompletely lubricated during manufacturing.
Photo courtesy of Avantor
(continued on page 22) 20
Medical Design & Outsourcing
Materials_3-24_Vs2-JH-FINAL.indd 20
3 • 2024
www.medicaldesignandoutsourcing.com
2/28/24 11:01 AM