Characterization techniques are essential for evaluating the properties and behavior of smart materials involved in four-dimensional (4D) printing. Smart materials possess unique properties that respond to external stimuli such as temperature, pressure, electric fields, or magnetic fields. Characterization helps in understanding these properties thoroughly, including how they change under different conditions. Thermal characterization provides insights into thermal properties, transition temperatures, heat resistance, and thermal conductivity, influencing the performance of 4D printed components. Mechanical characterization techniques, including tensile, compressive, and shear testing, assess the mechanical behavior and recovery of shape memory materials. Surface roughness analysis evaluates the quality and aesthetics of 4D printed parts. Microstructure analysis techniques analyze the internal structures, defects, and surface roughness of printed components. Dimensional accuracy and precision play a crucial role in guaranteeing the fidelity of printed parts to the intended design. Non-destructive testing methods allow for quality inspection without damaging the parts. Shape memory testing techniques evaluate the response of materials to stimuli. These characterization techniques enable optimization of design parameters, part quality, and performance, driving advancements in four dimesnional additive manufacturing.