Shape Memory Polymers and Their Emerging Applications

Shape-memory polymers (SMP) are a class of materials that are better known as smart materials. The smartness of the SMP comes from their tunability properties allowing them to tweak into various shapes and orientations as per the desired applications. Many animals can change the stiffness of their skin, adopt the colors from the environment, change their appearance according to needs and in case of approaching danger, etc. Inspired by these above natural phenomena, many smart materials have been developed by researchers over the last decade and SMP is one of them. SMP polymers can easily be manipulated to the desired shape by changing their physical and chemical parameters such as temperature, light, ultrasound, chemical cross-linkage, crystallization, etc. SMP is a suitable candidate for designing novel metamaterials or programmable metamaterials in which the temporary shape can be retained and also imposed and controlled through programming such that the initial shape of the material can be recovered by an application of an external stimulus. The best characteristic of these polymers is the retain-ability of original or temporary shape in different stimuli fields prompting this material to have a memory effect for shape retainability. Due to such exceptional properties of the SMP, these smart materials find wide applications in Aerospace, Biomedical micro-devices, Robotics, Acoustics, Electronics, Textiles, Bionics engineering, and many other contemporary fields.This chapter discusses some fundamentals related to the fabrication strategies, emerging application aspects, and memory retention/ programming aspects of the shape memory polymers. The current state of the art and future directions has also been outlined to provide a roadmap for smart memory polymers-based technologies.