Abstract

With the same level of measurement accuracy, more portable and miniaturized measurement systems will have greater advantages, providing users with more flexible and convenient measurement solutions. Here, we introduce a new type of digital image correlation (DIC) system that incorporates a binocular meta-lens, featuring a simple and compact configuration.

Meta-lens is one of the promising flat optical imaging devices that are ultra-thin, customizable, and well-suited for use in confined spaces. We evaluated this binocular meta-lens based DIC(BM-DIC) system through classic in-plane and out-of-plane translation tests, followed by a bending test on a helicopter wing model to capture 3D displacement and deformation fields. For in-plane translations, the system achieved high precision with a standard deviation (σ) below 2 µm. Despite a small baseline of 4 mm, the system maintained a σ of approximately 32 µm for out-of-plane translations.

Comparative analysis with conventional dual-camera stereo DIC systems showed that the BM-DIC system maintains an acceptable relative error margin of about 1% in measured strain fields despite a 75-fold reduction in baseline length. This research demonstrates the integration of DIC techniques with advanced meta-lens technology, indicating substantial potential to enhance the capabilities of DIC technology in experimental solid mechanics.