Papers by Keyword: Micromotor

Abstract: An electrothermally actuated planar micromotor has been developed for multi degree-of-freedom (DoF) motion, including rolling along the vertical or horizontal axes, spinning about the z-axis, and also the out-of-plane piston motion. In this design, a light-weight spherical solder ball rotor with plastic core is supported by electrothermal actuator array (EAA). Each bimorph actuator consists of the silicon and aluminum layers to produce large vertical deflection due to their distinct coefficients of thermal expansion (CTE). The micromotor fabrication procedures involve standard CMOS-MEMS processes. Rolling and spinning motions of the spherical rotor are performed by driving the electrothermal actuators with multi-phase signals, and the piston motion can be achieved by synchronizing the drive signals to all actuators without phase difference. The dynamic behavior of this micromotor has been successfully predicted by multibody dynamics simulation software. Such unique dynamic motions of this planar micromotor device show promising capabilities in Optical Coherence Tomography (OCT) and Optical Coherence Microscope (OCM) applications. If this sphere is mounted with a highly-reflective mirror platform, it can be used to divert the light beam to achieve a full 360° circumferential scan about the optical axis.

Abstract: This article describes a sub-millimeter micromotor, one of achievements of MEMS (microelectromechanical systems) science that is driven by electrostatic force. A simplified analytical dynamical model for microelectrostatic motor is presented. The model involves formulas for calculation of non-fringing electrostatic field forces for any rotor and stator pole combination, for any number of poles. Both tangent and normal forces are derived. The article shows how to increase torque created by tangential force and how to decrease friction created by normal component. The model is useful for development of motor control system and further motor analysis. The analytical model is quantitatively compared to finite element model (FEM) created using Ansys and Matlab software. By changing the number of poles in both models, the ripple of the motor torque is researched using both methods.

Abstract: An electrostatic motor is a very complex dynamical system whose performance critically depends on the shape of the rotor and stator, number of poles, clearances between axis and rotor, friction, rotor vibrations, and levitation, etc. There are many possible micromotor constructions depending on the required accuracy, the speed of rotation and power of the motor. This work shows the technology required to build a micromotor using UV lithography. Studies of vibration characteristics using ANSYS and MATLAB modeling software and an experimental analysis to optimize the dynamical properties of the system and to improve its manufacturing process are also shown.