SBIR-STTR Award

This proposal develops a methodology to detect and map regions of incipient failure in opaque composite materials using a terahertz (THz) metamaterial laminate (MML) whose polarimetric response is sensitive to local strain. This proposal develops a practical THz metamaterials and metrology system that can be adapted to a large range of opaque composite material applications. Specifically, MML structures and THz scanning instrumentation will be designed that is capable of measuring strains in composite materials ranging from 0.1 to 5% at a spatial resolution better than 5 mm. The technique will be based on spatially and spectrally resolved polarimetric reflection of THz radiation from the MML. Overall strain measurement precision will be 10% of actual strain. The MML will be developed as both an aftermarket film attachment and as an embedded composite layer to provide flexibility for the technology in test and evaluation of a wide array of composite materials and parts. Both in situ strain and post-strained impact history mapping will be supported as an integral part of the overall MML materials and metrology design process. The designed strain metrology system will be capable of mapping a 1000 cm2 surface area in less than 1 hour.