Effect of 3D Printing Parameters on Self-Driven Deformation Characteristics of Intelligent Hydrogel Actuators

摘要

By changing printing parameters, a serious of hydrogel actuators with high mechanical strength and multiple deforma-tion were successfully prepared through three-dimensional (3D) printing. Base on the enhancement role of cross-linking density of hydrogel inks, nanofibrillated cellulose (NFC) was treated as reinforcement phase to realize controllable regu-lation of rheology characteristics. With the increase of NFC content, stress and strain values of hydrogels increased gradually. Attributed to swelling rate and gel-sol transition point, hydrogel with 12 mg/mL NFC was treated as 3D printing ink. The 3D printing parameters significantly affected self-driven deformations. The hydrogel actuators with 0°/90°, 45°/135° and Archimedes chord configurations owned bending, spiral and twist deformations, respectively. The hydrogel actuators with relative larger length-width ratio exhibited higher spiral degree. The high precise anisotropic swelling property of printed bilayer structure was the self-driven deformation mechanism of hydrogel actuators. The combina-tion of hydrogels and 3D printing extended the application of intelligent hydrogels.