Characterization of ceramic phononic crystals prepared with additive manufacturing: Ultrasonic technique and finite element analysis

Phononic crystals (PCs) are composed of two or more elastic materials arranged periodically. One of the important characteristics of PCs is the band gap. Band gap is the frequency range within which elastic waves are not allowed to transmit. With the band gap, applications of PCs include filters for body waves and surface acoustic waves. In the recent years, the additive manufacturing technique has been widely employed to fabricate objects with complicated geometries like PCs. In this study, samples of ceramic PCs were fabricated with the additive manufacturing technique. In addition to that Finite Element Analysis (FEA) was employed to predict the band gaps of PCs fabricated with the traditional and the additive manufacturing technique. Experimental measurements with pulsed ultrasound technique together with fast Fourier Transform (FFT) were employed to measure the band gaps. In general, measurement results agree well with the FEA results. The outcomes of this study suggest a new PCs fabrication method based on the additive manufacturing technique.