Ultrastretchable and Self-Healing Double-Network Hydrogel for 3D Printing and Strain Sensor Sijun Liu Lin Li 10.1021/acsami.7b07445.s001 https://acs.figshare.com/articles/journal_contribution/Ultrastretchable_and_Self-Healing_Double-Network_Hydrogel_for_3D_Printing_and_Strain_Sensor/5242405 On the basis of the thermoreversible sol–gel transition behavior of κ-carrageenan in water, a double-network (DN) hydrogel has been fabricated by combining an ionically cross-linked κ-carrageenan network with a covalently cross-linked polyacrylamide (PAAm) network. The κ-carrageenan/PAAm DN hydrogel demonstrated an excellent recoverability and significant self-healing capability (even when notched). More importantly, the warm pregel solution of κ-carrageenan/AAm can be used as an ink of a three-dimensional (3D) printer to print complex 3D structures with remarkable mechanical strength after UV exposure. Furthermore, the κ-carrageenan/PAAm DN hydrogel exhibited a great strain sensitivity with a gauge factor of 0.63 at the strain of 1000%, and thus, the hydrogel can be used as sensitive strain sensors for applications in robotics and human motion detection. 2017-07-14 00:00:00 DN 3 D structures covalently cross-linked polyacrylamide Strain Sensor motion detection hydrogel 3 D Printing ionically cross-linked κ- carrageenan network strain sensors UV exposure gauge factor κ- carrageenan pregel solution strain sensitivity Self-Healing Double-Network Hydrogel self-healing capability