Scientists Grow Liquid Crystal Flowers That Act as Lenses

Scientists have made another advance when it comes to using liquid crystals as a medium to assembling structures. They've managed to grow liquid crystal "flowers" that can be used as lenses.

The new "flowers" are three-dimensional arrays of liquid crystals. The petals are made out of transparent liquid crystal and radiate out in a circle from a central point, which resembles a compound eye. Because of this structure, the flowers can be used as lenses.

This work with liquid crystals is actually an example of a growing field of nanotechnology known as "directed assembly." In directed assembly, scientists aim to manufacture structures on the smallest scales without having to individual manipulate each component. Instead, they set out precisely defined starting conditions and let the physics and chemistry that govern these components do the rest.

In order to actual grow these liquid crystals, the researchers "planted" silica beads--essentially, polished grains of sand. Planted at the top of a pool of liquid crystal, these beads caused flower-like patterns of defects to grow around them. Using this bead made it so that the interface was not flat. In addition, the surface tension on the bead also makes it so that the "petals" of the flower are arranged in a tiered, convex fashion. Because the liquid crystal can interact with light, the entire assembly can act as a lens and focus light to a point underneath a bead.

"It's like an insect's compound eye, or the mirrors on the brightest telescopes," said Randall Kamien, one of the researchers, in a news release. "As we learn more about these systems, we're going to be able to make these kinds of lenses to order and use them to direct light."

The findings are published in the journal Physical Review X.