Phononic crystals guide, monitor, and manipulate acoustic and elastic waves. They can control the propagation of elastic waves, hence have a broad range of applications.
The phononic crystals have the property of sensing and understanding the volumetric properties of liquids. This property is gaining a lot of scientific interest.
Scientists from France and Germany propose designing a tubular phononic crystal (TPC) to sense the biochemical and physical properties of a liquid filling the hollow part of the tube. This TPC is structured with a periodic arrangement of washers along the tube.
Such mixed solid/liquid systems present absolute or polarization-dependent band gaps.
Scientists introduced Fabry-Perot (F-P) cavity inside the periodic structure to create peaks inside the band gaps and dips inside the passbands in the transmission spectrum.
These peaks and dips are sensitive to the density and speed of sound of the fluid flowing inside the pipe. Hence, the system shows higher sensitivity to the variations of the mass density than the sound velocity.
Thanks to the sufficiently strong coupling of the F-P modes at the fluid/solid interface, the TPC consequently becomes an innovative platform for sensing applications.
The experiment will be performed using a 3-D printer. Scientists will work on all physical parameters to fully determine the liquid: density, velocity, and viscosity.
They will introduce thermo viscous equations and conduct comparisons between sensing gas and liquids.
The findings impact the development of acoustic metasurfaces (AMM) in liquid. Until now, AMM was mainly developed in the air. There is increased interest in applying the AMM concept for underwater applications.
- A. Gueddida et al., Tubular phononic crystal sensor, Journal of Applied Physics (2021). DOI: 10.1063/5.0051660