Abstract

In modern microelectromechanical systems (MEMS), the efficient manipulation of higher-order modes is crucial for enhancing the functionality and precision of resonators used in various applications. As devices become increasingly miniaturized and complex, optimizing the activation and detection of these modes can lead to significant improvements in performance and energy efficiency for variety of sensing and actuation applications.

Addressing these challenges, this thesis presents an original 4-electrode design for micromachined membrane resonators (micro drum), implemented using microfabrication techniques. The device is actuated electromagnetically with an externally created magnetic field. Vibrational modes up to the 4th mode are efficiently and selectively actuated based on different connections and combinations of the electrodes. The selective actuation is verified by optical measurements. An on-chip electrical readout mechanism is studied for the electrically measured frequency responses, and the output signals of the higher-order modes response are intrinsically amplified.

A reduced-order model is established for the membrane structure to help understand the actuation of the degenerate (1, 1) modes. Complete selectivity is achieved when the nodal lines of the degenerate modes are aligned with the boundaries of electrodes. In general, the nodal lines are in arbitrary positions, and the electrically measured frequency responses of the degenerate modes are different in amplitude. A correlation between the nodal line angle and the frequency responses is then derived and verified.

Improved applications in mass sensing and parallel logic operations are proposed and demonstrated on the micro drum resonator based on the selective actuation, electrical readout, and nodal line angle dependence. 

Biography

Lvjun Wang received the B.Sc. degree from University of Science and Technology of China, Hefei, China in 2016 and the M.Sc. degree from King Abdullah University of Science and Technology, Thuwal, Saudi Arabia. He is currently a Ph.D. candidate with King Abdullah University of Science and Technology, Thuwal, Saudi Arabia. His research interests include fabrication, characterization, and dynamic analysis of MEMS and NEMS structures.