Self-Assembly of Functional Coatings: Superomniphobic Coatings
This project aims to develop transparent and robust superomniphobic coatings (non-wettable by water and organic liquids) on glass surfaces. In this project we plan developing self-assembly approaches to fabricate superomniphobic coatings made of silica colloidal particles. Applications: various coating technologies including photovoltaic, sensor, optical, and biomedical use cases.
Marking System Technology
Surface electrostatic properties of polymer-based particles are the basis for particle deposition and adhesion to surfaces they are applied to. The project involves making and attaching several organometallic additives to particles having different polymer core compositions for advancing print performance. Applications: improved printing technology.
Rapid Prototyping and Printing of Tunable Metamaterials
This project involves the fabrication of layered or nanopillared metamaterial structures exhibiting tunable and hyperbolic dispersion characteristics. Processes are being developed to pattern increasingly small meta-atoms structures into phase changing bismuth strontium titanate (BST). Applications: energy harvesting, thermal management, sensing, imaging, and camouflage.
Development of Modeling and Design Algorithms
A fast rigorous coupled mode (RCM) algorithm and an algorithm that included a coordinate transformation to ease the complexity of modeling periodically patterned metal surfaces were developed during the first two years of the project. This year’s objective is to create a library of computer code that can quickly model transformational optical surfaces and volumes. Applications: improved metamaterial modeling and simulation.
Photon Sorting and Multi-Wavelength Detection
This project involves the use of photon sorting to develop dual-wavelength infrared detectors. The objectives of the project are to investigate the use of nanoplasmonic antenna structures for dual IR wavelength absorption and to develop dual wavelength IR detectors using compound cavity array metasurfaces. The structures developed in this project will allow for efficient, light weight, inexpensive dual wavelength IR detectors that can be used for numerous sensing applications.
Novel metallic feature structures (metasurfaces) that allow for local control of the phase as an optical beam is transmitted through a surface were developed. The objectives of this project are to investigate these metasurfaces using a low cost, rapid development approach, to increase the efficiency of the refraction, develop designs that allow for pixilated arrays of flat lens, and investigate tuning capabilities that would allow for the steering of microwave and infrared beams. Applications: improved imaging systems, beam steering, spatial light modulators, and other optical devices.
This project investigates active metamaterials, characteristically defined by its active composition of the meta-atoms. The key differentiator for our active metamaterials approach is that we focus on making the meta-atoms active while most other groups are using active host materials in order to compensate the loss of the meta-atoms. Our approach changes meta-atoms’ spectral responses, notably from loss to transparent or gain for the spectral intensity response while maintaining the abnormal spectral phase response. Applications: innovative direction for controlled and engineered metamaterials.
This project involves designing, fabricating and testing structures with extraordinary sharp focusing provided by mesoscale high-index dielectric microspheres and strong nanoplasmonic field enhancement in metallic nanostructures. Applications: imaging, computer chips, integrated circuits, and semiconductor detectors and emitters.
Conformal Metamaterial Antennas
It is anticipated that the combination of non-Foster tuning of electrically small antenna elements, combined with a metamaterial substrate will lead to a moderate element beamwidth and a narrow array factor beamwidth to allow a very wide beam sweep in a phased array antenna. This project focuses on conformal elements and arrays that are circular in nature with radiation in both endfire as well as broadside directions, with a fixed beam as well as a shaped and steered beam. Applications: broader bandwidth and lower profile RADAR and communication antenna performance for aircrafts, missiles, and rockets.
Gain Enhancement to Vivaldi Antenna using Metamaterials
This project involves fundamental research on periodic metamaterial structures that will be incorporated into Vivaldi antenna’s aperture to mitigate reductions in gain. The Army has a requirement to develop a conformal directive antenna that meets a very stringent height requirement, which necessitates trade-offs in gain and bandwidth.
Conformal Artificial Magnetic Conductor Backed Antenna Structures
This project will develop split ring resonator (SRR) metamaterials structures to be used as artificial magnetic conductors. By taking advantage of the strong resonance induced by these structures, the permittivity and permeability shall be independently adjusted, enabling reduction of the size and weight of communications antennas for Army platforms. The development of novel composite materials for use in antenna systems, which can be integrated within the platform’s structure, will enable the mitigation of communication system issues while reducing visual signature and relieving platform crowing.
Design and Fabrication of Low-Loss Low-Index Optical Metamaterials
This project involves the development of the capability to make nanoparticles of a given size and coat them with ligands that can control their relative spacing. Nanoparticles of transparent oxide materials give low loss bulk properties. Applications: optical surface coatings and low observable/cloaking structures.
Low-Loss Negative-Index THz Lens
The objective of this project is to develop a small lens structure and compare its measured superresolving capability with a detailed numerical simulation. Applications: imaging.
Optical Composite Materials
The goal of this project is to develop and validate a design tool for bulk metamaterials that takes into account coupling effects between nanostructured meta-atoms.
High-Resolution E-Field Mapping for IR Metamaterials
High resolution E-field mapping using scanning near-field optical microscopy (SNOM), which is based on measuring IR light scattered from the near-field by an atomic microscope tip, was developed. E-field mapping can be useful in characterizing metamaterials and in determining the truncation effects for arrays of metamaterials of finite sizes. Applications: energy and defense.
Liquid Crystal Directional Prism
The objective of this project is to develop an improved optical isolator. Currently, commercially available optical isolators utilize the Faraday effect in magneto-optical materials. However, these materials tend to have high optical absorption that causes thermal depolarization and substantially degrades an isolation quality. Applications: improved telecommunication devices.
Dispersions of Nano-Diamonds
Tunable optical metasurfaces demonstrate outstanding capabilities of material parameters modifications by changes in the structural architecture at the nano-scale level. This project will investigate the effects of electrophoresis to modify a structure of metasurface by using diamond nanoparticles, with sizes much smaller than the wavelength of light. Applications: light harvesting.
Slow and Fast Light Using Metamaterials
The field of slow and fast light has been receiving a lot of interest recently due to their promise for use in many applications from sensing to telecommunications. The objective of this project is to develop structures that exhibit slow and fast light behavior. Applications: sensing and telecommunications.
Self-Assembly of Split-Ring Resonators
The objective of this project is to introduce a modular chemical/biological approach to arrange self-assembling lipid nanodisc scaffolds with interchangeable nanoparticle building blocks for the production of metamaterials. This approach will enable the development of a vast range of metamaterials with pre-designed optical responses.
Multifunctional Periodic Mechanical Metamaterials
This project involves design and fabrication of periodically ordered structures and composites. These structures are shown to have a unique combination of stiffness, strength, and energy absorption, as well as damage tolerance. The acoustic and elastic wave propagation in these structures will be studied to extend their multifunctionalities. Applications: sound filters, acoustic wave guides, acoustic mirrors, noise and vibration control for high precision mechanical systems.