Three-Dimensional Printed Multiresponsive Structures of Smart Hydrogel

Hydrogels, as soft smart materials, have been widely used in the manufacturing of responsive biomedical structures. The manufacturing process of smart hydrogels is critical for their application; however, the production efficiency and precision of the extrusion-based 3D printing method for the fabrication of responsive structures of gelatin-based hydrogels have not been extensively studied. In this study, a gelatin-based shape memory hydrogel was designed and prepared with the addition of sodium alginate, tannic acid, and sodium iron ethylene diamine tetra acetic acid to improve its mechanical strength and photothermal properties. The printability of the hydrogel based on extrusion-based 3D printing was studied under different mixture ratios of hydrogel components. The appropriate printing parameters and formulas of the hydrogel were investigated to determine the structural strength of printing structures. Furthermore, the shape memory properties of printed structures under different printing conditions were studied. The biomedical applications of the shape memory behavior of printed structures were explored. The proposed hydrogels and manufacturing process allow the realization of 3D printed shape memory smart hydrogel structures and provide details and solutions for the design and integration of multifunctional hydrogels.