Numerical and Experimental Study of a Phononic-Fluidic Sensor Using a Cubic Unit Cell with Spherical Void

This paper presents a design study of a phononic-fluidic cavity sensor to measure volumetric properties of different liquids. A 3D finite element model shows that the sensor performance drastically depends on the lattice constant of a phononic crystal unit cell. As a result, the numerical model predicts the quality factor up to 200. As proof of concept, we fabricated several sensors using microstereolithography printing, and performed their experimental characterization. We achieved a good match of resonance frequency in the numerical model and experiments. Our experimental results displays a quality factor up to 55, and clearly separated resonance frequencies for different liquids in the cavity, with frequency shifts corresponding to differences in density and speed of sound.