Room-Temperature Wide Measurement-Range Optical Fiber Fabry–Perot Tilt Sensor With Liquid Marble

We proposed a novel miniature liquid marble-based room-temperature optical fiber tilt sensor by using Fabry-Perot (F-P) interferometric detection, with the advantages of simple fabrication, wide range, good linearity, and low cost, aside from the immunity to electromagnetic interference. A mercury marble with a diameter of 1.3 mm and a length of 10 mm, acting as a light reflector, was dispensed into a capillary tube preprocessed by hydrophobic agent, therefore forming F-P interference with one end of a single-mode fiber. The developed sensor exhibited tilt-induced sensitivities of 6.62 μm/ms
^-2
and 4.28 μm/ms
^-2
with corresponding linearities of 3.44% and 4.28% within the ranges of 0°-90° and -90°-0°, respectively, due to asymmetric cavity lengths. The measured results were in agreement well with the governing model incorporating with contact angle hysteresis between mercury marble and capillary substrate.