Microelectromechanical Systems II: Design Principles

This course transitions from fundamental physical principles to the systematic modeling and design of functional Microelectromechanical Systems (MEMS). Divided into five sections, it provides the analytical tools necessary to transform theoretical micro-physics into high-performance sensors and actuators used in global industry. The first section introduces the methodology of Lumped-Element Modeling, teaching students how to simplify complex multiphysics systems into equivalent mass-spring-damper circuits.

This module establishes the groundwork for analyzing both static and dynamic MEMS behavior, with a focus on predicting frequency response and the importance of mechanical resonance. The second section focuses on Electrostatic MEMS Devices, the most common architecture in the field. Students will explore the principles of capacitive sensing and the trade-offs between sensitivity and linearity.

Critical design constraints are examined, specifically the "pull-in" instability limit and the various noise sources that impact the resolution of capacitive micro-sensors. The third section explores Resonant MEMS, detailing how micro-structures are engineered for timing and frequency control. Topics include the analysis of mode shapes, lateral resonators, and the "Quality Factor" (Q-factor).

Students will learn how to manage damping and energy loss mechanisms to ensure frequency stability and minimize drift in precision applications. The fourth section dives into Inertial MEMS Devices, specifically accelerometers and gyroscopes. This module provides a rigorous explanation of the Coriolis effect and how it is harnessed for angular rate sensing.

Students will analyze mechanical design trade-offs, focusing on how bias, noise, and temperature effects influence the performance of navigation-grade inertial units. The final section addresses Thermal and Specialty MEMS, alongside material selection and reliability. This module covers the use of Joule heating as a deliberate design tool and identifies common failure modes such as thermal buckling and fatigue.

Students will learn to navigate design pitfalls to ensure the long-term reliability of micro-systems in harsh environments. By the end of this course, students will be able to translate physical requirements into mathematical models and engineering designs. Through the study of inertial and resonant systems, they will gain the expertise to design the "brain and senses" of modern autonomous systems, wearables, and aerospace technology.