Swelling-induced snap-buckling in a 3D micro hydrogel device, inspired by the
insect-trapping action of Venus flytrap, makes it possible to generate
astonishingly fast actuation. We demonstrate that elastic energy is effectively
stored and quickly released from the device by incorporating elastic
instability. Utilizing its rapid actuation speed, the device can even jump by
itself upon wetting.Comment: 4 pages, 3 figure
