Dependence of Structural Design on Effective Young's Modulus of Ti/Au Multi-layered Micro-cantilevers

Gold-based micro-electro-mechanical-systems (Au-MEMS) capacitive accelerometers can simultaneously realize high sensitivity and miniaturization because of the high mass density of Au. In order to further improve the sensitivity of the Au-MEMS capacitive accelerometers, Young's modulus of the cantilever-like spring part connected to the movable component is a key parameter. Considering the size effect in the mechanical property of metallic materials on micro-scale, the design of the spring part is expected to reflect their Young's modulus; that is, effective Young's modulus (E_eff). In this study, we clarify effects of the structural designs of the Au-based micro-cantilevers on their E_eff by experiments and finite element analyses (FEA) simulations. The E_eff of the Au micro-cantilevers having Ti/Au multi-layered structures is evaluated by resonance frequency method, which demonstrates the key structural parameters affecting their E_eff. The FEA calculations show a consistent trend with that observed in the experimental results.