LAUSR

The quality factor ( Q- factor) is an important parameter for mechanical resonant sensors, and the optimal values depend on its application. Therefore, Q- factor control is essential for microelectromechanical systems (MEMS). Conventional methods have some restrictions, such as additional and complicated equipment or nanoscale dimensions; thus, structural methods are one of the reasonable solutions for simplifying the system. In this study, we demonstrate Q- factor control using a variable phononic bandgap by changing the length of the periodic microstructure. For this, silicon microstructure is used because it has both periodicity and a spring structure. The bandgap change is experimentally confirmed by measuring the Q- factors of mechanical resonators with different resonant frequencies. The bandgap range varies depending on the extended structure length, followed by a change in the Q- factor value. In addition, the effects of the periodic structure on the Q- factor enhancement and the influence of stress on the structural length were evaluated. Although microstructures can improve the Q- factors irrespective of periodicity; the result of the periodic microstructure is found to be efficient. The proposed method is feasible as the novel Q- factor control technique has good compatibility with conventional MEMS.