Multiple-stimuli response composite hydrogels with high mechanical property and triple shape memory effect

Shape memory hydrogels are widely used in soft robots and other fields. However, it is difficult to realize multiple-shape memory hydrogels with high strength and simple driving modes. The mechanical properties of a hydrogel were improved in this study through the creation of a double network hydrogel using a combination of gelatin and PAAm. Additionally, hydrogen bonding was introduced into the structure of the hydrogel through the incorporation of acryl 11-aminodecanoic acid (A11AUA). The helical structure of gelatin and the semi-crystalline segment of A11AUA provide enabling the hydrogels to realize a triple shape memory effect at different temperatures. In addition, we found that the hydrogel could also complete shape memory behavior in the FeCl₃ solution due to the carboxyl group in A11AUA. And we prepared composite hydrogel to realize remote infrared driving by introducing nano Fe₃O₄. We believe that this triple-shape memory hydrogel with high mechanical property and multiple stimulus responses can expand the application of hydrogel in soft robots, sensors, and other fields.