Tracing evolutions of elastomeric composites in shape memory actuators: A comprehensive review

Shape memory polymers (SMPs) are, by far, one of the most intriguing subjects of smart materials with myriads of applications in various disciplines, such as biomedical, aerospace, automotive, and so on. By compiling the durable elasticity of elastomers and SMPs, one can obtain a low-weight material with exclusive recovery abilities and cost-effective features. However, elastomer-based SMPs have significant drawbacks in the case of mechanical and conductive properties, which are usually resolved by introducing nanofillers in the elastomer matrix. The resultant materials are known as polymer nanocomposites in which spectacular and amended properties could be observed. This purpose is accomplished by effectively disperse and distribute the fillers throughout the matrix and, indeed, by establishing a robust interaction between the polymer chains and filler components. Furthermore, adding functional fillers can enable the SMPs’ responsivity to other stimulation methods rather than heat, such as electricity, magnetic field, and light, expanding their applications where heat stimulation is unsatisfactory. This paper is dedicated to laying a solid foundation of shape memory effect in elastomeric polymers, procedures of composite fabrication, as well as addressing the amelioration of thermal, mechanical and electrical properties of SMP (nano-)composites. An intriguing application of the stimulated elastomer SMPs is that they have the capability to be actuated in which their primary shape is recovered in a different way. The present paper has offered a comprehensive discussion on the recent progress of elastomeric composites in shape memory actuators with the perspective of material structure and microstructure, fabrication process and mechanisms, principles, and performance. (nano)composites and blends are elaborately categorized into various groups, encompassing stimulus method and the type of inclusion. The other primary focus of this review is on the most recent studies on elastomeric SMPs. Likewise, the necessary information for highly performance is precisely deliberated. • The promising applications of polymer nanocomposites are highly dependent on the efficacy of microstructure and preparation route. • We present a comprehensive summary of recent progress in the development of rubbery polymer in shape memory applications. • The concepts, electrical and mechanical properties, and assembly strategies of elastomeric composite overviewed. • Different stimulus methods of shape-memory materials were reviewed conceptually and practically. • A key challenge is to increase the performance of rubbery nanocomposite, preserving flexibility and embedding nanofiller.