A review on progress in magnetic, microwave, ultrasonic responsive Shape-memory polymer composites

Shape memory polymers (SMPs) are the novel class of Smart materials where they memorize their shape/configuration and return to their original shape upon application of a variety of external stimuli. Triggering of SMPs can be done by various external stimuli such as heat, electricity, magnetism, light, water, microwaves, chemical solvents, pressure, and sound. Over decades, there has been a great deal of research for the different triggering of SMMs in both industrial and academic researchers in the automobile, aerospace, biomedical, electronics, and textiles. Heating is the conventional way of triggering the SMPs, but direct heating is not always practical in some circumstances because heating has both design and physical constraints. For example, in minimally invasive surgery, drug-releasing systems, artificial muscles, intravascular stents, self-stitching. The remote-controlled stimulus for SMPs has been a challenging task for controlling shape in real-time over decades. To overcome this, Indirect heating of SMMs has come into the field. Therefore it is essential to design a new triggering mechanism for the actuation of SMPs. Alternating magnetic field, light, microwave, and ultrasound would satisfy some of these constraints. In this report, the recent advances made in the development of indirect actuation of SMPs to recuperate their shape have been reviewed. Indirect heating mechanisms could be further split into Magnetic resistive Joule heating, Microwave, Ultrasound, Light (UV, infrared) SMPs. These new triggering mechanisms can enable us to design SMP for new targeted applications. © 2021