4D Printed Shape Memory Polymers and Their Composites in the Field of Biology

Abstract

In the past two decades, stimulus-responsive shape memory polymers (SMPs) have made significant progress, demonstrating desirable characteristics such as shape memory properties, deformability, and biocompatibility in response to external stimuli. The development of SMP composites (SMPCs) has brought high resilience and new functions, including thermal actuation, electrical actuation, magnetic actuation and biocompatibility. The enhanced remote controllable features and functions further expand the application of SMPS in the biomedical field, such as surgical applications to replace hand-held surgical instruments and drug delivery systems. This article systematically introduces the preparation methods, thermal drive and magnetic drive mechanisms of SMPs and SMPCs in 4D printing, and focuses on reviewing their current application status and development potential in biomedicine. At the same time, the challenges and bottlenecks of current 4D printing technology are pointed out, such as material properties, printing accuracy and response controllability. In the future, the development of it still needs to rely on multidisciplinary cross-disciplinary cooperation and technological innovation, and make breakthroughs in new structural design, biocompatible material development and modeling tool optimization to achieve the next generation of high-performance smart medical solutions.