Silicon cavity resonator based on locally resonant phononic crystal

In this paper, a silicon cavity-mode resonator based on locally resonant phononic crystal (PnC) is experimentally studied. The PnC resonator is realized by creating line defects on a two-dimension (2-D) silicon PnC. The silicon resonator was fabricated by micro machining process, and tested by a combination of the fluid coupling method and Laser Doppler Vibrometer. Two resonant frequencies (7.93MHz and 8.03MHz) were observed in the PnC resonator. The experimental results agree well with the simulated band structures of the perfect PnC and PnC resonator, that the resonant frequencies of the designed PnC resonator are in the range of the phononic bandgaps (PnBGs).