Phononic Crystal Made of Silicon Ridges on a Membrane for Liquid Sensing

Abdellatif Gueddida (1) , Victor Y. Zhang (1, 2) , Laurent Carpentier (1) , Jérémy Bonhomme (3) , Bernard Bonello (4) , Yan Pennec (1) , Bahram Djafari-Rouhani (1)

1 PHYSIQUE - IEMN - Physique - IEMN
2 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
3 INSP - Institut des Nanosciences de Paris
4 INSP-E3 - Acoustique pour les nanosciences

We propose the design of a phononic crystal to sense the acoustic properties of a liquid that is constituted by an array of silicon ridges on a membrane. In contrast to other concepts, the ridges are immersed in the liquid. The introduction of a suitable cavity in the periodic array gives rise to a confined defect mode with high localization in the cavity region and strong solid–liquid interaction, which make it sensitive to the acoustic properties of the liquid. By using a finite element method simulation, we theoretically study the transmission and cavity excitation of an incident flexural wave of the membrane. The observation of the vibrations of this mode can be achieved either outside the area of the phononic crystal or just above the cavity. We discuss the existence of the resonant modes, as well as its quality factor and sensitivity to liquid properties as a function of the geometrical parameters. The performance of the proposed sensor has then been tested to detect the variation in NaI concentration in a NaI–water mixture.

Mots clés: acoustic sensor; phononic crystal; defect mode; liquid viscosity; transmission curve; dispersion curve; membrane

Domaines: Micro et nanotechnologies/Microélectronique; Instrumentations et Détecteurs [physics.ins-det]

Abdellatif Gueddida, Victor Y. Zhang, Laurent Carpentier, Jérémy Bonhomme, Bernard Bonello, et al.. Phononic Crystal Made of Silicon Ridges on a Membrane for Liquid Sensing. Sensors, 2023, 23 (4), pp.2080. ⟨10.3390/s23042080⟩. ⟨hal-04086892⟩