During what is called a “first-order structural phase transition” process, the material moved into a mixed-phase in which some parts of the system completed the transition and others did not. The material had spontaneously organized into an ordered structure as it changed from one phase to another. “After consulting with colleagues at the University of Minnesota, University of Georgia, and City University of New York, we realized that we may have discovered something quite special that can potentially have some unique applications.” “At first we thought this must be a mistake, but soon realized that the periodic pattern is a mixture of two phases of the same material with different crystal structures” said Bharat Jalan, the senior author of the study and an expert in material synthesis who is the Shell Chair in the University of Minnesota’s Department of Chemical Engineering and Materials Science. During their research, they noticed the surprising formation of checkerboard patterns at the nano scale similar to the metamaterial structures fabricated in the costly, multistep process. In this new research, a University of Minnesota team was studying a thin-film material called strontium stannate or SrSnO 3. Usually these nano-scale materials are painstakingly produced in a specialized clean room environment over days and weeks in a multi-step fabrication process. These materials can have unique properties which make them ideal for a variety of applications from optical filters and medical devices to aircraft soundproofing and infrastructure monitoring. In general, metamaterials are materials made in the lab to provide specific physical, chemical, electrical, and optical properties otherwise impossible to find in naturally occurring materials. The research was published and featured on the cover of Nano Letters, a peer-reviewed scientific journal published by the American Chemical Society. Their results show the realistic possibility of designing similar self-assembled structures with the potential of creating “built-to-order” nanostructures for wide application in electronics and optical devices. PAUL () - A team led by University of Minnesota Twin Cities researchers has discovered a groundbreaking one-step process for creating materials with unique properties, called metamaterials. Metamaterials have enabled us to come up with artificial structures and designs that can perform optical functionalities which are not achievable with natural materials.Discovery is big step forward in creating new materials used in a variety of applications including optical devices and sensors Here we design and implement three important applications of metamaterials as: 1. Wideband and wide-angle efficient beam deflector and Multi-functional angular filter. By lithogra-phy being a major hinder on the way to mass production and cost-effectiveness, most of our works are lithography-free. We have introduced Manganese (Mn) for the first time as a very promising metal for broadband absorption and have used it in all our works. Four different Mn-based broadband absorbers are designed and fabricated in different chapters. Mn is used in the Metal-Insulator-Metal (MIM) cavity, annealed MIM configuration, top-layer-patterned MIM configuration, and random nanopyra-mids. It is shown in all works that Mn has a much better performance compared to other metals. For instance, in the work based on random nanopyramids, we obtain ultraviolet (UV) to far-infrared (FIR) perfect absorption by exploiting a lithography-free method and only by coating a single Mn layer on a high-roughness substrate. Moreover, using the combination of the MIM cavity and an electro-optic material, we have shown that a lithography-free color filter can be achieved that covers the whole visible spectrum by changing the voltage from -12 to 12 volts. Finally, in a structure composed of Silicon nano-rods, an ultra-wideband and wide-angle highly-efficient beam deflection is obtained.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |