Micro-scale electro-mechanical-systems are at the cutting edge of modern technology. They have small size and mass and allow the implementation of various types of control. Many consumer, industrial, and military devices rely on these systems for sensing and signal conditioning. Speed, precision, stability, and reliability are important characteristics of their performance. Vibrations are at the core of the operation of many of these micro-electro-mechanical systems. This project involves a fundamental study of the vibrations of these systems, with the goal to establish what properties limit their performance and how this performance can be improved. The development of physics-based models for these vibrations, using both theoretical and experimental tools, will provide key understanding that will allow for new modes of operation and enhanced capabilities. And, while the experimental aspects of the project will focus on micro-electro-mechanical systems, the vibration and noise models developed will be general and applicable to optical systems and to even smaller mechanical devices that operate at the nanoscale, paving the way for further progress in nanotechnology. The broader impacts of the project include outreach, mentoring and training of undergraduate and graduate students, inclusion of students from underrepresented groups, development of classroom materials motivated by the research, and dissemination of results. The project will result in multidisciplinary training of students at four universities who will benefit from the combined analytical, computational, and experimental research experiences.
Because of their small size, micro-electro-mechanical vibrational systems are intrinsically noisy. Another consequence of the small size is that obtaining a sufficiently strong signal requires operating in a regime where the vibration amplitudes are large, making the vibrations nonlinear. The interplay of nonlinearity and noise leads to new phenomena, and these must be understood in order to avoid them, or to utilize them in applications. In this context, nonlinear resonant phenomena are particularly interesting, rich, intellectually challenging, and promising for implementation in micro-scale devices. The behavior of resonating nonlinear modes in the presence of decay and noise, as well as the fundamental microscopic mechanisms of noise, decay, and nonlinearity are poorly understood. Nor is it understood how to detect and characterize fluctuations in nonlinear systems, as they are intervened with the nonlinearity in a nontrivial way. The work will address these issues both theoretically and in experiments. It will also develop new techniques for experimental control and characterization of resonating modes using optical and electrostatic methods. The principal investigators have an established record of collaboration, which will strengthen a close connection between the theoretical and experimental work.
