Case Western Reserve University researcher improves LCDs with 3-D nanoimagi...( Charles Rosenblatt professor of phys...)

Charles Rosenblatt, professor of physics and macromolecular science at Case Western Reserve University, and his research group have developed a method of 3D optical imaging of anisotropic fluids such as liquid crystals, with volumetric resolution one thousand times smaller than existing techniques. A research paper detailing the team's findings appeared in the advanced online publication of Nature Physics.

The molecules of these fluids, such as liquid crystals and ordered polymers, gels, and emulsion, can be oriented by magnetic or electric fields and thus can control the polarization properties of light. This is how liquid crystal displays in televisions, laptop computers, and other digital devices operate. Designing these and future devices requires a detailed knowledge of the molecular order. Until now much of the available information was based on inference from macroscopic experiments.

Using Rosenblatt's new technique, which provides detailed visual renderings of structures at the level of tens of nanometers, about 1/1000th the diameter of a human hair, we are able to create a much more detailed and nuanced picture of the structure. This will facilitate improvements to existing devices and make entirely new applications possible. Moreover, many fundamental scientific questions that deal with phase transitions or the nature of topological defects can be studied in far more detail than previously possible.

His system builds on existing techniques in near field scanning optical microscopy (NSOM) for 2D imaging. Traditionally, NSOM entails placing a very tiny optical fiber close to the specimen surface, in this case the substrate on which the anisotropic fluid resides. As the substrate is scanned back and forth below the fiber's aperture, a computer records the intensity of the light that emerges from the fiber and interacts with the surface, as well as the position of the fiber. The computer processes the information and produc
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