Basics 101: Silicone

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Silicone, chemically known as polydimethylsiloxane, is a highly stable material that was discovered by English chemist F.S. Kipping. In the 1940s, researched and tested to help with the war effort, silicone became commercially viable.

Silicone was first produced by Dow Corning as a paste used to protect electrical sparking equipment in planes. Now well known for its resiliency, this material has expanded it uses to a variety of industries, including medical, in both extruded and molded components.

Here is a quick primer of some of features and benefits of silicone. While this won’t cover everything about silicone, this list can help you decide if this is the right material for your medical application.

Features and Benefits

  • Silicone is a thermoset material. This gives this material a very wide temperature range to work in since it will not melt like a thermoplastic but is not as easily recycled.
  • Silicone is inert. This makes it a biocompatible material that is well suited to meet USP Class VI and ISO 10993 requirements and has a long history in medical applications.
  • Silicone has a low surface energy. Used in many applications to repel liquids and to release easily, it may be challenging if it needs to bond to another material. Attaching silicone to other materials may require a look at insert/overmolding or 2-shot molding to make it work in your device.
  • Silicone is highly elastic. Elasticity allows silicone to retain its shape after deformation which makes it an ideal material in dynamic applications such as enteral feeding or drug delivery pumps. To modify this property to suit your application you may want to look at a custom compound.
  • Silicone is permeable. Used as a matrix for drug delivery, this is a great characteristic in specific medical applications but understanding its limitations is very important when working with gasses and vapor.

For material properties, see our Bio-Sil formulations here. If you want to learn more or have questions on how silicone is processed, take a look at our Silicone Extrusion and Medical Molding pages.