Patent ID: 8879052

Claim:
A system for determining shear stress in structures, the system comprising: a substrate support connected to a structure and having a first optical grating with a plurality of features defining a first spatial period; a floating element having a second optical grating with a plurality of features defining a second spatial period, the floating element being suspended over the first optical grating and flexibly connected to the substrate with compliant tethers or springs, wherein the first and second gratings are in an optical path with one another and form a Moiré fringe pattern when illuminated that relates to a shear-stress induced translation of the floating element; an imaging device; and an optical fiber bundle operably connected to the structure and having a distal end in proximity to the floating element for detecting and delivering the Moiré fringe pattern to the imaging device, wherein in a delivery path of a signal reflected from the floating element, the system consists of the optical fiber bundle between the floating element and the imaging device.