This recent featured work evaluates the potential of tailoring 4D printing to Hygromorph BioComposite (HBC), which paves the way for the construction of a new generation of sustainable shape-changing metamaterials with a sequential response. HBCs are made of continuous flax fibres that have been proven to be relevant for actuation and thus 4D printing due to their hygromorphism function.
https://www.sciencedirect.com/science/article/pii/S0264127521007139?via%3Dihub