Toward Metamaterials: Printing Artificial Bone
If you want to design new materials that are durable, lightweight and environmentally sustainable, it makes sense to look at old kinds: Natural composites, such as bone. Bone is strong and tough because its two constituent materials, soft collagen protein and stiff hydroxyapatite mineral, are arranged in complex hierarchical patterns that change at every scale of the composite, from the micro up to the macro. While researchers have come up with hierarchical structures in the design of new materials, going from a computer model to the production of physical artifacts has been a persistent challenge because the hierarchical structures that give natural composites their strength are self-assembled through electrochemical reactions, a process not easily replicated in the lab. read more