Bone-inspired dynamically adaptive materials: Current efforts and future opportunities

Abstract The natural world contains a diverse range of solutions that allows for living organisms to dynamically adapt their structure and mechanical properties to meet environmental demands. For example, coral reef is able to accumulate reinforcing calcium carbonate from wave agitation and water current that stabilizes gaps in the structure and increases the reef density and strength through diagenetic reef cementation. Bone responds to repeated stress by translating deformations and fluid movement in the bone matrix into cellular signals that trigger bone formation through mechanotransduction. Utilizing these mechanisms as inspiration, synthetic materials have been developed that utilize stress-generated piezoelectric charges to attract mineral ions to form reinforcing mineral layers that can repair defects and damage over time and extend material lifetime. In this article, we examine natural adaptive processes that give inspiration for new synthetic materials with similar dynamic adaptive properties. We also introduce the capabilities of existing bioinspired synthetic materials, current challenges these systems face, potential application areas of this technology, and future research opportunities of these adaptive materials. Graphical abstract