Scientists Grow Liquid Crystal "Flowers" That Can Act as Lenses
2 January 2014
Scientists at the University of Pennsylvania have successfully grown a three-dimensional, liquid-crystal array in the form of a flower that resembles an insect's compound eye. Thanks to their composition, these flowers can be used as lenses, thus setting the stage for the use of liquid crystals as a medium for assembling structures that will be useful in producing optical switches and other applications, the university said on its website.
The work with liquid crystals is an example of a growing field of nanotechnology called "directed assembly" and follows previous experiments conducted by the team of material scientists, chemical engineers and physicists, when they obtained patterns of "defects" in nanoscale grids and rings, using tiny posts as templates. Now, the researchers have produced a more sophisticated pattern using an even simpler template - a 3-D array in the shape of a flower.
To create the lenses, this time the scientists used silica beads that are basically polished grains of sand, which they planted at the top of a pool of a liquid crystal, causing patterns of petal-shaped bumps shaped like flowers to grow around them. These beams can all function as lenses because the liquid crystal can interact with light, focusing it to a point underneath the bead.
The structure resembles an insect's compound eye, or the mirrors on the largest telescopes, said one of the researchers, Randall Kamien. As knowledge about these systems grows, it will be possible to produce these kinds of lenses to order and use them to direct light, he added.