Design of phononic crystal plate with folded helical beam for vibration isolation in MEMS resonators

Enhancing the vibration resistance of micro-electro-mechanical systems (MEMS) resonators in complex environments is a critical issue that urgently needs to be addressed. This paper presents a chip-scale locally resonant phononic crystal (LRPnC) plate based on a folded helical beam structure. Through finite element simulation and theoretical analysis, the bandgap characteristics and vibration suppression mechanisms of this structure were thoroughly investigated. The results show that the structure exhibits a complete bandgap in the frequency range of 9.867 - 14.605 kHz, and the bandgap can be effectively tuned by adjusting the structural parameters. Based on this, the influence of the number of unit cell layers on the vibration reduction performance was further studied, and a finite periodic LRPnC plate was constructed. Numerical studies have shown that the LRPnC plate can achieve more than -30 dB of vibration attenuation within the bandgap and effectively suppress y -direction coupling vibrations caused by x -direction propagating waves. In addition, its chip-scale size and planar structure design provide new ideas and methods for the engineering application of phononic crystal technology in the field of MEMS vibration isolation.