Ph.D Thesis

Ph.D StudentDegani Ofir
SubjectInvestigation and Modeling of Actuation and Sensing
Mechanisms in Microoptoelectromechanical Systems
and their Applications
DepartmentDepartment of Electrical and Computer Engineering
Supervisor PROFESSOR EMERITUS Yael Nemirovsky


Microelectromechanical Systems (MEMS) stand for the integration of miniature sensors and actuators with VLSI electronics into a single combined microsystem. Together, they power-up the capabilities of integrated electronics to interact with the surrounding world and to provide improved devices to the conventional electronics.

This research addresses the study of motion sensing and actuation mechanisms that are required in almost any micromachined device. It focuses on novel approaches for modeling the non-linear and instable physics (known as pull-in) of the electrostatic actuation as well as novel devices based on such actuators. Furthermore, this work focuses on a novel motion sensing method aimed for detecting sub-pico-meter displacements within a sensor microsystem. This method emphasizes the relation between MEMS and scientific research of nano phenomena. The new method is referred to as enhanced modulated integrative differential optical sensing (E-MIDOS).

The research highlights are: the DIPIE algorithm, a 100 times faster and far more accurate algorithm for pull-in extraction; the general theorem on the relation between charge control and voltage control pull-in phenomena; the a-lines modeling and characterization approach for pull-in hyper-surface of multiple source electrostatic actuators; implementation and characterization of novel micromirrors with adjustable pull-in.

Further highlights are: establishing models for the sensitivity and resolution of the E-MIDOS method in micromachined integrated microsystems such as accelerometers; establishing a model that predicts the performance of such sensors; implementation of prototype accelerometers and their characterization exhibiting a noise equivalent acceleration of ~2[ug/ÖHz] (i.e., 2[pm/ÖHz] noise equivalent displacement) for natural frequency of 500[Hz] and dynamic range above 120[dB].