Sensing the heavy water concentration in an H 2 O–D 2 O mixture by solid–solid phononic crystals

A new method based on phononic crystals is presented to detect the concentration of heavy water (D 2 O) in an H 2 O–D 2 O mixture. Results have been obtained and analyzed in the concentration range of 0%–10% and 90%–100% D 2 O. A proposed structure of tungsten scatterers in an aluminum host is studied. In order to detect the target material, a cavity region is considered as a sound wave resonator in which the target material with different concentrations of D 2 O is embedded. By changing the concentration of D 2 O in the H 2 O–D 2 O mixture, the resonance frequency undergoes a frequency shift. Each 1% change in D 2 O concentration in the H 2 O–D 2 O mixture causes a frequency change of about 120 Hz. The finite element method is used as the numerical method to calculate and analyze the natural frequencies and transmission spectra of the proposed sensor. The performance evaluation index shows a high Q factor up to 1475758 and a high sensitivity up to 13075, which are acceptable values for sensing purposes. The other figures of merit related to the detection performance also indicate high-quality performance of the designed sensor.