Abstract: A Moiré interferometric-based shear-stress sensor includes a substrate support. The substrate includes a first optical grating disposed in or on the substrate, the first grating having a plurality of features defining a first spatial period. A floating element having a second optical grating is disposed in or on the floating element. The second grating has a plurality of features defining a second spatial period. The floating element is suspended over the first grating and flexibly connected to the substrate with compliant springs, wherein the respective gratings are in an optical path with one another. Upon irradiation, the sensor forms a Moiré fringe pattern which relates to a shear-stress induced translation of the floating element.