Biomimetic Nanocomposites*

Materials with difficult-to-attain combination of multiple properties - mechanical, electrical, chemical, optical, thermal, and transport, – represent the quintessential bottleneck for nearly all technologies. Nanocomposites with molecular, nano-, meso-, and microscale levels of structural engineering can provide such properties, while intrinsic ability of nanoscale components to self-assemble make them suitable for scalable synthesis.

Biomimetic nanocomposites exemplified by nanostructured nacre-like assemblies, provide a generalized approach to engineer materials. Continuing this research, we learn that the unique mechanics of tooth enamel can be replicated combining out-of-plane nanoscale columns with molecular precision of layer-by-layer (LBL) assembly. These composites reveal remarkably high vibrational damping thought to be impossible for stiff materials.

The novel type of biomimetic nanocomposites are those based on aramid nanofibers (ANFs). They spontaneously assemble into three-dimensional percolating networks reminiscent of cartilage. The nanoscale structure of ANF composites reveal nanoscale porosity that can be controlled by nanofiber branching. The latest results from multiple groups demonstrate that ANF composites resolve some of the essential property bottlenecks for ion-selective membranes, dendrite-resistant electrolytes, and structural batteries.

One of the emerging fields for biomimetic nanocomposites are optical devices. The high strain and strong polarization rotation make possible metaoptical devices with kirigami composites with wide-angle diffraction gratings for LIDARs and highly efficient quarter wave plates for THz scanners. Chiroplasmonic composites with mirror-asymmetrical 3D shapes of gold nanoparticles represent the first dynamically reconfigurable metaoptical composites for visible, near-IR and THz ranges of electromagnetic spectrum.