© SMRC
The colors in this newly discovered phase of liquid crystal shift as researchers apply a small electric field.
Researchers at the University of Colorado Boulder's
Soft Materials Research Center (SMRC) have discovered an elusive phase of matter, first proposed more than 100 years ago and sought after ever since.
The team describes the discovery of what scientists call a
"ferroelectric nematic" phase of liquid crystal in a study published today in the Proceedings of the National Academy of Sciences. The discovery "opens a door to a new universe of materials," said co-author Matt Glaser, a professor in the
Department of Physics.
Nematic liquid crystals have been a hot topic in materials research since the 1970s. These materials exhibit a curious mix of fluid- and solid-like behaviors, which allow them to control light. Engineers have used them extensively to make the liquid crystal displays (LCDs) in many laptops, TVs and cellphones.
Think of nematic liquid crystals like dropping a handful of pins on a table. The pins in this case are rod-shaped molecules that are "polar" — with heads (the blunt ends) that carry a positive charge and tails (the pointy ends) that are negatively charged. In a traditional nematic liquid crystal, half of the pins point left and the other half point right, with the direction chosen at random.
A ferroelectric nematic liquid crystal phase, however, is much more disciplined. In such a liquid crystal, patches or "domains" form in the sample in which the molecules all point in the same direction, either right or left. In physics parlance, these materials have polar ordering.
Noel Clark, a professor of physics and director of the SMRC, said that his team's discovery of one such liquid crystal could open up a wealth of technological innovations — from new types of display screens to reimagined computer memory.
"There are 40,000 research papers on nematics, and in almost any one of them you see interesting new possibilities if the nematic had been ferroelectric," Clark said.
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