WARF TECHNOLOGIES

UW-Madison researchers have developed a nacre-mimetic ferroelectric metamaterial with exceptional piezoelectricity and fracture toughness. Ferroelectric (e.g. poly(vinylidene fluoride)-co-hexafluoropropylene/lithium-doped sodium potassium niobate (PVDF-HFP/Li-KNN)) and conductive (e.g. polylactic acid/carbon black (PLA/CB)) composites were developed, mimicking the soft bio-adhesive and tough aragonites in nacre, respectively, as the building blocks to construct a lamellar heterostructure. The interdigitated configuration and uniform quality among layers enabled effective accumulation of piezoelectric charges from each layer. A piezoelectric coefficient of over 130 pC/N was achieved from the as-printed 3D structure, reaching the same level as piezoceramics. The nacre-mimetic structure together with the strong interfacial adhesion brings high resistance to crack propagation, leading to a high fracture toughness exceeding most natural and synthetic piezoelectric materials. Based on this structure, full-sized biomimetic piezoelectric bones were created with anisotropic piezoelectricity, strong toughness, and tunable modulus.

For More Information About the Inventors

• Xudong Wang

Tech Fields

• Materials & Chemicals : Composites