The use of moisture-responsive materials in 4D printing

The objective of this research paper is to compile a list of key moisture-sensitive smart materials used in 4D printing. These materials have applications in various fields, including industrial and medical, and the list can be used as a reference for creating 4D-printed sensors and actuators.The smart materials used in 4D printing are discussed, and a description of each material is given, including its principle, applications and areas of use.We have discovered a large number of different materials that are sensitive to moisture and have identified those that are most essential for use in 4D printing.According to the results of this research, the moisture-sensitive materials used in 4D printing have very limited use and application, and the majority of these materials are still in the research and development stage.This review article provides researchers interested in using smart materials to exploit 4D printing in the industrial and medical fields, as well as in many other disciplines, with a means to identify the most widely used and prevalent moisture-sensitive materials.