Nano Focus: New optical materials manipulate light into 3D profiles
- PDF / 201,108 Bytes
- 1 Pages / 585 x 783 pts Page_size
- 65 Downloads / 172 Views
us New optical materials manipulate light into 3D profiles
T
he discovery of new materials is being rapidly accelerated through the use of computational methods that can screen the constituent elements for a desired application. While simple materials systems and structures can be easily predicted using these methods, more complex systems can prove challenging due to the increased number of potential configurations. Evolutionary algorithms, a sort of “survival of the fittest” methodology that sequentially generates and weeds out potential solutions to converge on an optimized result, offer the possibility to accurately predict complex systems while reducing computation time. These design methods have been used in the past to predict metamaterial structures that can operate at terahertz frequencies but encounter problems at optical frequencies that require a finer computational grid to account for losses, leading to prohibitively longer computation times. Teri W. Odom and colleagues at Northwestern University now report a bottom-up strategy that uses a custom-built evolutionary design algorithm to predict a new class of optical materials. These new “lattice opto-materials” are detailed in the
equipment for this task: glands in the abdomen release a molten protein mixture, which flows through ducts that reorder the proteins into a fiber before releasing it through spinnerets. For humans, it has proven to be more of a challenge. One promising solution uses microfluidics, where fiber assembly takes place at the interface of a fluid protein stream and a water-insoluble liquid like oil. It’s too soon to call spider silk the next miracle material—many of the technologies being developed, though promising, are still in their nascent stages, and the exact properties of a given spider silk depend on the complex interplay between its molecular makeup and the fiber structure. Nevertheless, opportunities for its eventual use abound.
Randy Lewis, a Utah State University researcher who was not involved in the review article but has been studying spider silk for 25 years, points out that the potential for the material goes beyond the strong, lightweight fabrics one might expect. “We have found that we can make a variety of things other than fibers from spider silk,” he says, like adhesives, coatings, and highly absorbent sponges. The authors of the review agree. “We think some of the most exciting applications aren’t the ones that follow the obvious properties of spider silk—applications in biophotonics and sensing, for example,” said Brown. Laurel Hamers
November 7, 2014, issue of Nano Letters (DOI: 10.1021/nl5040573; p. 7195). Lattice optomaterials can be used to concentrate light into discrete focal points in the optical far-field and produce arbitrary threedimensional (3D) light profiles. They function based on the discretiza- Lattice opto-materials can manipulate visible light to produce a tion of a plasmonic film variety of three-dimensional profiles from two-dimensional grids nano-sized holes milled into a substrate. Repr
Data Loading...
