The fabrication of shape-memory hydrogel scaffolds not only requires biocompatibility, micrometer resolution, high mechanical strength, but also requires a low polymerisation threshold in high-water content environment to incorporate microstructures with biological tissues. Towards this goal, scientists from China and Australia developed a new hydrogel formula that full fills this goal and demonstrated water-responsive structures with a shape-memory effect at a micrometer scale. This work is of importance for the development future reversible microdevices in biomedical engineering.