The article by Behl, Razzaq, and Lendlein reviews the development and applications of multifunctional shape-memory polymers (SMPs). SMPs are materials that can change their shape in response to heat, a property known as the shape-memory effect (SME). The authors highlight the technological significance of SMPs in various fields, including packaging, textiles, and biomedical applications. They discuss the fundamental principles of SME, which involves the entropy-driven recovery of mechanical deformation after external stress application and temporary fixation by physical crosslinks. The review covers different polymer network architectures that enable SME, including covalent polymer networks, thermoplastic SMPs, and multimaterial systems. These architectures are designed to integrate additional functions such as electrical conductivity, color change, and degradability. The authors also explore the changes in properties like permeability, transparency, elastic properties, dielectric properties, and enthalpy during SME. Key aspects of the review include: - **Polymer Network Architectures**: Covalent and thermoplastic SMPs are discussed, emphasizing the role of different thermal transitions and the formation of physical and chemical crosslinks. - **Multimaterial Systems**: These systems combine multiple polymers or inorganic particles to achieve multifunctionality, such as interpenetrating polymer networks (IPNs). - **Additional Functions**: The article discusses how SME can be combined with other functions, such as electrical conductivity, color change, and degradability, to create multifunctional SMPs. - **Property Changes**: The review details how SME affects properties like permeability, transparency, elastic properties, dielectric properties, and enthalpy, providing insights into the design of SMPs for specific applications. The authors conclude by discussing future challenges and potential applications of multifunctional SMPs, emphasizing the importance of transferring the concept of multifunctionality to emerging shape-memory technologies.The article by Behl, Razzaq, and Lendlein reviews the development and applications of multifunctional shape-memory polymers (SMPs). SMPs are materials that can change their shape in response to heat, a property known as the shape-memory effect (SME). The authors highlight the technological significance of SMPs in various fields, including packaging, textiles, and biomedical applications. They discuss the fundamental principles of SME, which involves the entropy-driven recovery of mechanical deformation after external stress application and temporary fixation by physical crosslinks. The review covers different polymer network architectures that enable SME, including covalent polymer networks, thermoplastic SMPs, and multimaterial systems. These architectures are designed to integrate additional functions such as electrical conductivity, color change, and degradability. The authors also explore the changes in properties like permeability, transparency, elastic properties, dielectric properties, and enthalpy during SME. Key aspects of the review include: - **Polymer Network Architectures**: Covalent and thermoplastic SMPs are discussed, emphasizing the role of different thermal transitions and the formation of physical and chemical crosslinks. - **Multimaterial Systems**: These systems combine multiple polymers or inorganic particles to achieve multifunctionality, such as interpenetrating polymer networks (IPNs). - **Additional Functions**: The article discusses how SME can be combined with other functions, such as electrical conductivity, color change, and degradability, to create multifunctional SMPs. - **Property Changes**: The review details how SME affects properties like permeability, transparency, elastic properties, dielectric properties, and enthalpy, providing insights into the design of SMPs for specific applications. The authors conclude by discussing future challenges and potential applications of multifunctional SMPs, emphasizing the importance of transferring the concept of multifunctionality to emerging shape-memory technologies.