4D printing of composites: Challenges, opportunities, and paths to commercialization

4D printing is a revolutionary technique that has gained tremendous attention in recent years for its ability to revolutionize the manufacturing industry. 4D printing technology is now taking additive manufacturing to the next level in the direction of sustainable and intelligent manufacturing. The integration of 4D printing with composite materials has expanded the opportunities to print composite products that can transform into predefined shapes when subjected to external stimuli without any complexities. Due to this unique characteristic, the composites printed using 4D printing have incredible potential to be used in numerous applications such as aerospace, defence, biomedical, architecture, consumer goods, and fashion industries. However, as with any emerging and promising technology, several challenges must be addressed. This chapter summarizes the challenges and opportunities associated with 3D/4D printing of composites and its commercialization. The social, economic, and environmental aspects of 4D printing have also been highlighted.