Bioinspired materials are designed and engineered to mimic the biological functions of nature; however fast actuation is an important but challenging task to recreate in the lab. In a recent study, Wenxin Fan and co-workers in the interdisciplinary departments of materials science, engineering, chemistry, biochemistry and macromolecular science in the USA and China, presented a new paradigm to design responsive hydrogel sheets that could exhibit ultrafast and inverse snapping deformation. They engineered the hydrogel sheets with dual-gradient architecture to accumulate elastic energy in the polymers by converting prestored energy for rapid reverse snapping and energy release.