(Digital Presentation) 4D Printing of Inter-Crosslinking Network Structure Gel with Hinge Structure

Abstract

4D printing [1] is a new interdisciplinary research area made possible by the merger of scientific developments in additive manufacturing and smart materials [2]. It is a technology that allows 3D printed objects to be deformed over time by applying specific external stimuli [3] and is currently attracting attention as a technology to program biological-like movements into the internal structure of 3D printed objects. In previous research, the movement and deformation of the model has been controlled by devising the shape of the structure, such as a bilayer structure consisting of two materials with different physical properties [4]. However, it is difficult to realize the deformation in different directions simultaneously. The purpose of this research is to develop a 4D printing technology that can simultaneously deform each part of the same object in any direction.To develop a 4D printing technology that can simultaneously deform each part of the same object in any direction, we analyzed the principle of 4D printing by swelling. We measured the swelling rate, swelling speed, compression test, and deformation amount in order to investigate the effects of material and laser irradiation frequency. As a result, it was confirmed that the swelling rate and swelling velocity increased when the amount of the initiator, TPO, was increased from a specific laser irradiation frequency. It was also confirmed that the Young's modulus increased with the increase in the number of laser irradiation. Finally, based on these results, the deformation was measured by varying the amount of initiator and the number of laser irradiations, and it was confirmed that the deformation increased with increasing the amount of initiator and the specific number of irradiations.References Skylar Tibbits, " 4D printing: multi-material shape change", Archit. Des. 84, 116–121 (2014). https://doi.org/10.1002/ad.1710MD Nahin Islam Shiblee, Kumkum Ahmed, Ajit Khosla, Masaru Kawakami, Hidemitsu Furukawa, "3D printing of shape memory hydrogels with tunable mechanical properties." Soft Matter 2018, 14, 7809. https://doi.org/10.1039/C8SM01156GKumkum Ahmed, MD Nahin Islam Shiblee, Ajit Khosla, Larry Nagahara, Thomas Thundat, and Hidemitsu Furukawa. "Recent progresses in 4D printing of gel materials." Journal of The Electrochemical Society 167, no. 3 (2020): 037563. https://doi.org/10.1149/1945-7111/ab6e60MD Nahin Islam Shiblee, Kumkum Ahmed, Masaru Kawakami, Hidemitsu Furukawa, "4D Printing of Shape-Memory Hydrogels for Soft-Robotic Functions." Adv. Mater. Technol. 2019, 4, 1900071. https://doi.org/10.1002/admt.201900071