BLOGS

Fig. 1 Multimaterial 3D printing hydrogel with other polymers. (A) Illustration of the DLP-based multimaterial 3D printing apparatus. (B and C) Processes of printing elastomer and hydrogel structures, respectively. (D) Snapshot of a diagonally symmetric Kelvin form made of AP hydrogel and elastomer. (E) Demonstration of the high deformability of the printed diagonally symmetric Kelvin form. (F) Snapshot of a printed Kelvin foam consisting of rigid polymer, AP hydrogel, and elastomer. (G) Demonstration of the high stretchability of the printed multimaterial Kelvin foam. Scale bar, 5 mm. (Photo credit: Zhe Chen, Zhejiang University.)

Topics: Chemistry, Materials Science, Polymer Science

Abstract
Hydrogel-polymer hybrids have been widely used for various applications such as biomedical devices and flexible electronics. However, the current technologies constrain the geometries of hydrogel-polymer hybrid to laminates consisting of hydrogel with silicone rubbers. This greatly limits the functionality and performance of hydrogel-polymer–based devices and machines. Here, we report a simple yet versatile multimaterial 3D printing approach to fabricate complex hybrid 3D structures consisting of highly stretchable and high–water content acrylamide-PEGDA (AP) hydrogels covalently bonded with diverse UV curable polymers. The hybrid structures are printed on a self-built DLP-based multimaterial 3D printer. We realize covalent bonding between AP hydrogel and other polymers through incomplete polymerization of AP hydrogel initiated by the water-soluble photoinitiator TPO nanoparticles. We demonstrate a few applications taking advantage of this approach. The proposed approach paves a new way to realize multifunctional soft devices and machines by bonding hydrogel with other polymers in 3D forms.

3D printing of highly stretchable hydrogel with diverse UV curable polymers, Science Advances

Qi Ge^1,*,†, Zhe Chen^2,*, Jianxiang Cheng¹, Biao Zhang^3,†, Yuan-Fang Zhang⁴, Honggeng Li^4,5, Xiangnan He¹, Chao Yuan⁴, Ji Liu¹, Shlomo Magdassi^6, and Shaoxing Qu^2,†