Polydimethylsiloxane (PDMS) and liquid silicone rubbers (LSRs) are two widely used elastomers in the biomedical industry, offering unique properties and applications. This whitepaper aims to provide an in-depth comparative analysis of PDMS and LSRs, shedding light on their key characteristics, performance attributes, and suitability for various biomedical applications. By exploring their material properties, fabrication techniques, biocompatibility, mechanical properties, and processability, this study aims to assist researchers, engineers, and professionals in making informed decisions regarding the selection of the most appropriate elastomer for their specific biomedical needs. By understanding the strengths and limitations of PDMS and LSRs, we can identify the optimal material for diverse applications, ultimately driving advancements and innovations in the field of biomedical engineering.
Polydimethylsiloxane (PDMS) is a silicone elastomer widely employed in advanced microfluidic or lab-on-a-chip applications for creating devices with precise microstructures. PDMS offers exceptional attributes including high transparency, low surface energy, biocompatibility, and excellent chemical resistance. It is typically formed as a viscous liquid (before curing) or as a solid elastomer (after curing), depending on the degree of cross-linking. The material can be easily molded into diverse shapes and can be cured either at room temperature or through the application of heat.
Liquid silicone rubbers (LSRs) represent a diverse group of silicone elastomers that differ from PDMS in their chemical composition. LSRs are polymers comprising siloxanes with various side groups, such as hydride, vinyl, hydroxyl, phenyl, and trifluoropropyl. The composition of these side groups, along with factors like molecular weight distribution and the presence of additives or functional groups, determines the chemical properties and mechanical characteristics (e.g., hardness, flexibility, refractive index, moisture permeability, and solvent resistance) of a specific LSR formulation.