Micro-electro-mechanical systems (MEMS) are micron-scale machines used in everything from accelerometers to digital projectors. Resonating MEMS are critical to many everyday gadgets – without MEMS resonators, your iPhone would not know when to switch from landscape to portrait mode! I work on simulation tools to help engineers design these types of devices.
Broadly speaking, my MEMS work has involved three different types of devices. Early in my Ph.D., I worked on SUGAR, a simulator inspired in name and style by the SPICE family of circuit simulators. SUGAR is useful for understanding system-level models involving many interacting electrical devices or structural elements. For a deeper understanding of the physics individual devices and structures, it is useful to build detailed finite element models. During the latter part of my Ph.D. work, I built finite element models to understand the damping of very high-frequency resonators (RF-MEMS) intended for use in cell phone signal processing applications; this study involved not only some beautiful linear algebra related to structured eigenvalue problems, but also demonstrated some previously-unsuspected mode interference mechanisms that significantly impact device design. At Cornell, I worked with Erdal Yilmaz (Applied Physics Ph.D., 2016) on finite element simulations of micro-scale solid-wave gyroscopes; here, too, our work yielded both novel eigenvalue analysis methods and some fundamental, practical insights about types of fabrication issues most likely to cause issues with sensor drift.