High-resolution 1D moires as counterfeit security features

A moire is an interference pattern that appears when two different periodic structures are overlaid. The image created is extremely sensitive to small variations in the original layers and is thus very interesting for anti-counterfeit protection. We present a microfabricated 1D moire enabling complex high-resolution patterns as a significantly improved security feature that cannot be reproduced using standard printing methods. Furthermore, we demonstrate, theoretically and experimentally, that a microscopic deviation from the original design results in a macroscopic variation in the moire that is clearly visible to the naked eye. The record resolution achieved in the elements fabricated and the increased design freedom, make these high-resolution moires excellent candidates for a variety of visually appealing security applications.