According to examples, an optical fiber-based sensing membrane may include at least one optical fiber, and a substrate. The at least one optical fiber may be integrated in the substrate. The optical fiber-based sensing membrane may include, based on a specified geometric pattern of the at least one optical fiber, an optical fiber-based sensing membrane layout. The substrate may include a thickness and a material property that are specified to ascertain, via the at least one optical fiber and based on the optical fiber-based sensing membrane layout, a thermal and/or a mechanical property associated with a device, or a radiation level associated with a device environment.