Polydimethylsiloxane‐Based Composites: A Review of Design, Characterization, and Emerging Applications

ABSTRACT Polydimethylsiloxane (PDMS) is a widely used silicone elastomer owing to its flexibility, chemical inertness, optical transparency, and biocompatibility. However, its relatively low mechanical strength, poor thermal and electrical conductivity, and hydrophobic surface limit its performance in advanced applications. This review provides a comprehensive overview of recent strategies for enhancing PDMS through nanocomposites, particle‐ and fiber‐reinforced composites, surface modification, polymer blending, elastomeric hybridization, and elemental doping. The effects of these approaches on the mechanical, thermal, electrical, optical, and interfacial properties of PDMS are critically discussed. Boron nitride and ceramic hybrid fillers increase thermal conductivity from approximately 0.15 to 0.60–1.2 W m −1 K −1 , while silica nanoparticles and fiber reinforcements improve tensile strength by 20%–50%, depending on filler type and loading. Carbon‐based conductive fillers enhance electrical conductivity by several orders of magnitude, enabling applications in flexible electronics and strain sensing. Surface treatments such as oxygen plasma and UV‐ozone reduce the water contact angle from over 100° to below 20°–30°, improving wettability and interfacial adhesion for microfluidic and biomedical devices. Overall, rational composite engineering enables precise tailoring of PDMS properties, establishing PDMS composites as versatile multifunctional materials for healthcare, flexible electronics, energy systems, and other advanced engineering applications.