Characteristics of Two-Axis Gimbal-less Scanner with radial vertical combdrive actators

Microelectromechanical System (MEMS) scanners have been extensively studied in recent years due to their compactness and capability of optical beam steering, which can be applied to various applications such as optical fiber communication, biological imaging, and display technologies. In this thesis, a two-axis MEMS scanner driven by radial vertical combdrive actuators has been demonstrated. A cross-bar spring structure is designed to obtain two rotational degrees of freedom (DOFs), enabling the dual-axis rotation without gimbal structure. Both the vertical comdrive actuators and the torsion springs are hidden underneath the mirror to achieve a small form factor. The device is fabricated by a five-layer polysilicon surface micromachining process (SUMMiT-V). Three types of spring designs were evaluated with modal analysis using ANSYS and the resonant frequencies is measured as 7 kHz /12 kHz for x-axis / y-axis rotation. Moreover, devices with different parameter values are characterized and discussed. For one of the devices, the measured mechanical rotation angles of ?6.68? at 43 V and ?2.16? at 65.5 V for rotation about x- and y-axis, respectively.