August 10, 2009: US Sensor Systems says it has made the first advancement in sensors used in the oil industry in “almost 50 years” for oilfield seismic exploration and production.

The new device, an all-optical, fiber-optic omnidirectional geophone, requires no in-situ electronics, copper conductors, or electrical power. It incorporates a self-contained optical interrogation unit (using an optical time division multiplexing methodology) with integrated laser sources; all of the system electronics reside in the optical interrogator. Receiver electronics demodulate the optical signals from the geophones, translating them into digital electronic signals. A fiber optic telemetry cable provides the data path to and from the individual geophones. A single optical interrogator can address up to 128 individual geophones.

The sensor offers “a much clearer picture of untapped underground oil or gas” and meets requirements for “permanent 4D seismic monitoring,” says US Sensor Systems. It is currently being evaluated by a top global oil company for downhole monitoring. It also can be used for surface (land) or marine seismic applications, noted company CEO Jim Andersen, in a statement.

(Source: USSI)

July 28, 2009: Carl Zeiss is adding a nanopatterning engine to its CrossBeam FIB/SEM workstations to offer more flexible and precise control of the focus ion beam. Application examples include atom probe tip preparation, microstrainer, nano-optical elements (e.g., Fresnel-lenses), and custom structures.

Key features include:

– a “drawing program”-style interface, to speed up patterning of complex shapes (e.g. ellipses, rings, text etc.) “in a matter of minutes”;
-16-bit vector scanning with variable dwell time, raster modes, and integrated imaging;
– 3D patterning based on grayscale bitmaps;
– serial or parallel patterning of shapes with distinct parameters (e.g., beam current, dwell time, dwell spacing, direction, etc.)
– real-time visualization from the perspective of the patterning beam as well as live SEM imaging of the patterning process.

The standard version of the software supports 8 basic shapes, greyscale bitmap nanopatterning, text patterning, real-time image processing and FFT, image acquisition up to 6k × 6k, beam perspective imaging, and auto drift correction (Q4); it also includes an Operation Builder and Deflection Lists.

An “Advanced” upgrade beefs up the image acquisition to 32k × 32k and with high-speed imaging, and adds support for voids and outlines, slice list 3D NanoPatterning, threshold milling, set operations, overlap resolver, and a FIB assist imaging & endpointing enhancement tool.

Some examples of structures:

Spiral of ring-structures. Left: Perspective of the patterning beam. Right: Corresponding SEM view image. (Source: Carl Zeiss)

“NanObama” patterned based on greyscale bitmap. (Source: Carl Zeiss)

Pillar structure created using the same dose and beam current settings but different milling strategies. (Source: Carl Zeiss)

July 27, 2009: Researchers from Georgia Tech have been examining small green beetles whose properties may help divine interesting facts about optics and liquid crystals.

The work, published in the July 24 issue of Science, focuses on the iridescent metallic green beetle Chrysina gloriosa, whose exoskeleton offers a unique structure to create striking colors — specifically, it incorporates a liquid crystalline material (composed of ~10μm hexagonal cells, pentagons, and heptagons), with surface structures that self-assemble into polygonal shapes, in relation to the shell’s curvature.

A closer look, from the abstract:

In bright field microscopy, each cell contains a bright yellow core, placed in a greenish cell with yellowish border, but the core disappears in dark field. With use of confocal microscopy, we observe that these cells consist of nearly concentric nested arcs that lie on the surface of a shallow cone. We infer that the patterns are structurally and optically analogous to the focal conic domains formed spontaneously on the free surface of a cholesteric liquid crystal. These textures provide the basis for the morphogenesis as well as key insights for emulating the intricate optical response of the exoskeleton of scarab beetles.

“When we looked at the beetle’s surface, we found tiles in the shapes mostly of hexagons, pentagons and heptagons,” patterns that likely arise “because the liquid crystal must have defects on the surface when exposed to air, and those defects create the patterns in the beetle’s shell or exoskeleton,” said Mohan Srinivasarao, professor in the GaTech’s School of Polymer, Textile and Fiber Engineering, in a statement.

Examples of the jeweled beetle used in this study. In the second photo, the background is a close-up image of the insect’s light-reflecting structures. (Source: Georgia Tech)

The unique helical structure that reflects light of two specific colors, and of only left circular polarization, they noted. Solidified structures produced from a cholesteric liquid crystal and its defects on the beetle’s shell reflect bright green light (530nm wavelength) mixed with yellow light (580nm wavelength). The researchers speculate the specific colors and polarization may help ward off predators or help attract mates. Future work will study other insects with complex color-creating optical structures. “There are hundreds of thousands of species, and the way they generate color is just stunning — especially since it is all done with water-based systems, mostly based on the biopolymer chitin,” noted Mohan Srinivasarao. “This is self-assembly at several levels, and we need to learn a lot more to duplicate what these insects do.”

A slideshow of the Georgia Tech beetle research, put together by the National Science Foundation (NSF) which helped fund the work, can be viewed at: http://www.nsf.gov/news/newsmedia/beetles/.