Fabrication of shape memory gels using 3D printer (Conference Presentation)

Abstract

Hydrogels are three-dimensional polymeric networks capable of absorbing large amounts of water or biological fluids. Due to their high water content, porosity and low friction they closely simulate natural living tissue. The properties of a polymer gel depend on the chemical structures of the component molecule and can be controlled or tuned by external stimuli such as heat, optics, solvent, and pH. Shape-memory gels (SMGs) are unique materials that have the ability to return from a temporary deformed state to their permanent i.e. original shape induced by an external stimulus like temperature change. Poly(dimethyl acrylamide-co-stearyl acrylate) (DMMA-co-SA)-based SMGs show such behavior with high mechanical strength, transparency and moderate water content (≈30wt%). In this work, we applied stereolithography process to fabricate DMMA-co-SA SMGs and printed sample models like gel sheets and tubes. However, printing a transparent SMG was not an easy task due to several problems like sample turbidity, swelling during printing and shape deformation. We critically maintained these uses and compared the properties of 3D printed SMGs with that of conventionally synthesized SMGs. Finally, we analyzed the limitation and potential of 3D printing process and discussed a suitable approach for application of 3D printed SMGs as an actuator.