Abstract: Sensors include an optical source configured to emit a beam directed to an opposing surface having a reflectance pattern, and an optical detector situated in relation to the optical source to detect a portion of the beam reflected by the opposing surface and to produce an output signal that varies based on (i) a relative displacement between the reflectance pattern and the optical detector and (ii) a spatially variable reflectance resulting from the relative displacement. Reflectance patterns can be spatially variable and/or randomly arranged. Displacements in a compressive or tensile direction can be detected. Methods of operation and fabrication of sensors are also disclosed.

Abstract: Sensors include an optical source configured to emit a beam directed to an opposing surface having a reflectance pattern, and an optical detector situated in relation to the optical source to detect a portion of the beam reflected by the opposing surface and to produce an output signal that varies based on (i) a relative displacement between the reflectance pattern and the optical detector and (ii) a spatially variable reflectance resulting from the relative displacement. Reflectance patterns can be spatially variable and/or randomly arranged. Displacements in a compressive or tensile direction can be detected. Methods of operation and fabrication of sensors are also disclosed.