Tuning the quality factor of microcantilever using hydrodynamic coupling of micro structures

This study demonstrates the concept of controlling the quality factor of a micro-cantilever using hydrodynamic coupling of active mechanical structures. The active micro structures (auxiliary-cantilevers) adjacent to the micro-cantilever (operating-cantilever) are exploited to generate hydrodynamic force to change the air damping of the operating-cantilever. Thus, the quality factor of operating-cantilever can be increased or decreased by changing the phase of the excitation force on the auxiliary-cantilevers. In addition, the tuning range of quality factor can be controlled by varying the magnitude of the excitation force on the auxiliary-cantilevers or the adjacent distance between micro-cantilevers. In application, magnetic actuated micro-cantilever arrays were fabricated and characterized. Measurements demonstrate that the variation of quality factor is from -39% to +28% using the proposed approach.