The compound eyes found in insects and some sea creatures are marvels of evolution. There, thousands of lenses work together to provide sophisticated information without the need for a sophisticated brain. Human artifice can only begin to approximate these naturally self-assembled structures, and, even then, they require painstaking manufacturing techniques
About the study:
- It was published in Advanced Optical Materials.
- Engineers and physicists at the University of Pennsylvania have shown how liquid crystals can be employed to create compound lenses similar to those found in nature.
- Taking advantage of the geometry in which these liquid crystals like to arrange themselves, the researchers are able to grow compound lenses with controllable sizes.
- These lenses produce sets of images with different focal lengths, a property that could be used for three-dimensional imaging.
- They are also sensitive to the polarization of light, one of the qualities that are thought to help bees navigate their environments.
- Previous work by the group had shown how smectic liquid crystal, a transparent, soap like class of the material, naturally self-assembled into flower-like structures when placed around a central silica bead.
- Gharbi stated that given the liquid crystal flower’s outward similarity to a compound lens, we were curious about its optical properties.
- To make the lenses, the researchers used photolithography to fashion a sheet of micropillars, then spread the liquid crystal on the sheet.
- At room temperature, the liquid crystal adheres to the top edges of the posts, transmitting an elastic energy cue that causes the crystal’s focal conic domains to line up in concentric circles around the posts.