Synergizing chemistry: unveiling the potential of hybrid fillers for enhanced performance in shape memory polymers

Shape memory polymers (SMPs) are novel materials that revert to their original shape after undergoing a transient deformation in response to an external stimulus. This unique property makes them highly appealing for various applications due to their large flexibility, stretchability, and ability to function in rigorous and corrosive environments. However, SMPs face many key challenges, including low electrical and thermal conductivity, poor responsiveness to electromagnetic stimuli, and slow actuation. Recent advances in shape memory polymer composites (SMPCs) have centered on overcoming these limitations through the incorporation of hybrid fillers. These fillers, which consist of a combination of materials such as carbon nanotubes, graphene, nanoparticles, and metal particles, are designed to improve several properties of SMPs. For example, adding conductive fillers can enhance the material’s electrical and thermal conductivity, although additional fillers may be required to maintain its flexibility. Thus, hybrid fillers overcome the intrinsic shortcomings of SMPs by utilizing synergistic effects, where each component contributes to better performance. Despite these potential achievements, the role of hybrid fillers in SMPs has not been thoroughly discussed. To bridge this gap, this review focuses on recent developments in SMPCs, emphasizing how different filler combinations can enhance properties such as actuation, electrical and thermal conductivity, self-healing, and electromagnetic interference (EMI) shielding. It also examines the underlying principles driving these advancements, acknowledges ongoing challenges, and explores the potential future applications of hybrid filler technology. This research provides valuable insights into boosting SMP performance for advanced applications by highlighting the significance of hybrid fillers.