May 15 2014
Topics Covered
Applications
References
Moiré patterns occur when materials are overlapped with repetitive lines. It is a naturally occurring interference pattern created by overlaying similar, but slightly offset, templates. In physics, mathematics, and art, the moiré pattern is considered a secondary and visually obvious superimposed pattern.
For instance, in everyday life moiré patterns can be seen by looking through the folds of a nylon curtain of small mesh, or at two sheets of graph paper twisted 20-30° with respect to each other.
Moiré patterns occur anytime a semi-transparent object with a repetitive pattern is placed over another. When there is a slight motion of one of the objects, large-scale changes can be seen in the moiré patterns. These patterns are useful for demonstrating wave interference.
Moiré patterns magnify the differences between two repetitive patterns. Moiré patterns will not occur if the two materials are lined up exactly.
The slightest misalignment of two patterns will create a large-scale visible moiré pattern. If the misalignment increases, the lines of the moiré pattern will seem thinner and closer together.
Moiré patterns do not form in the materials, but are actually an image formed by the eye.
Applications
Moiré patterns are useful to represent fluid flow and potential fields. They are also used to solve problems in optics, wave motion, crystallography, mathematics, stress analysis, and psychology of perception.
Moiré patterns can find use in the following applications:
- Animation
- Currency
- Printing full-color images
- TV screens and photographs
- Marine navigation
- Strain measurement
- Image processing
References