s Developments and Applications of Moire Techniques for Deformation Measurement, Structure Characterization and Shape Analysis

As representative non-contact optical techniques, Moiré methods have been extensively used to visualize deformation distributions of materials, arrangements of structures, and shape features of objects in research and industrial fields. This article overviews the up-to-date developments of Moiré techniques and applications to in-plane and out-of-plane deformation measurement, planar structure characterization and three-dimensional shape analysis based on recently published patents. The planar periodic structure parameters, alignment accuracies, overlay errors, defects as well as distortions, and document security are able to be accurately detected. The heights or depths, three-dimensional shapes, three-dimensional surface profiles or topographies, and surface flatness are also effectively obtainable. The phase-shifting technique and the color technique have been used to improve the measurement accuracy. Further developments of Moiré techniques are promoted by the demands of high-accuracy, extremely small- or large-scale, multi-scale, dynamic, high-temperature, three-dimensional, and on-line measurements.