Non-destructive mapping of stress and strain in soft thin films through sound waves

Abstract

Measuring the in-plane mechanical stress in a taut membrane is challenging, but fundamental to basic research and practical applications, from engineering to tissues. Here, the authors propose an accurate measurement technique of the in-plane stress in thin films based on the speed of elastic waves measured through optical coherence tomography, and demonstrate it on a rubber membrane, common household plastic wrap, and leather skin of an Irish frame drum.