Abstract In this paper, we report the experimental results of the design and manufacture of a device in the form of a hollow bottle manufactured from a polymer for the measurement of hydrostatic pressure of microfluids in microcavities. The fabricated device bases its operation on the optical resonances of a capillary optical microresonator that couples the light coming from the evanescent field of an optical fiber taper with a central diameter in the range of 3-5 μm, exciting the resonant optical modes WGMs inside the cavity. The microcavity was manufactured using a heating-pressurization technique by a system built to measure which allowed reaching a minimum wall thickness in the central region of the order of 19.78 μm with a sensitivity of the order of 0.5567 nm/bar.