Static pressure response model of fluorescent pressure-sensitive film for underwater surface pressure measurement

The fluorescent pressure-sensitive film (FPSF) is a non-contact, deformation-based optical pressure sensor with high spatial resolution. The pressure response principle of FPSF is to convert pressure change into variations in fluorescent intensity through the deformation of fluorescent microspheres embedded within the film. To quantitatively analyze the pressure–deformation–intensity mechanism, a static pressure response model was established in this study. First, a finite element model was developed to predict the deformation of microspheres within the film under pressure. Second, the deformation-induced variation in fluorescent intensity was modeled with consideration of the light path blockage effect. The pressure calibration curve of the FPSF predicted by the proposed model was noted to be consistent with the experimental results of underwater calibration. In addition, the relationship between pressure sensitivity and the structural parameters of the FPSF were investigated using the pressure response model.