Bottom-Up Self-Assembly of Visible Wavelength Metamaterials

This program would investigate the feasibility of molecular-level “bottom-up” chemical processing to form metamaterials for operation in the visible and near-IR portion of the electromagnetic spectrum. Electrostatic self-assembly (ESA) processes would be used to pattern multilayer arrays of straight and curved conducting segments dimensioned to resonantly absorb electric and magnetic field components. ESA has been used through prior work to manufacture multilayered and patterned materials with controlled multiple constitutive properties, specifically high electron transport efficiency. Resonant segments would be formed from sparse arrays of individual metal nanoclusters. Electron transport in such arrays occurs by quantum mechanical electron hopping rather than by conventional drift field mechanisms such as those in bulk metal conductors; NanoSonic’s Metal Rubber™ is an example of a material that exhibits such behavior. Two “top-down” photolithographic patterning methods would be studied for integration with the self-assembly process, as an alternative to strictly patterning at the molecular level. The bottom-up and top-down processes would be compared in terms of resonant element patterning resolution and array periodicity, and the ability to potentially transition to large area spatial formats. Measurements of material properties, patterning resolution and far-field propagation would be used to downselect the optimal process for further development.