Author: Corey Alan StambaughPublisher:
ISBN:
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Languages : en
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Book Description
ABSTRACT: This dissertation details my research on the effects of fluctuations on vibrational systems driven out of equilibrium. Under the right conditions such systems will exhibit multiple stable states. When the fluctuations are large enough, the systems may overcome an activation barrier and switch from one stable state to another. The transitions lead to large changes in the system's vibrational amplitude. These changes can have a large impact on the performance and behavior of the system. The activation barrier plays a major role in determining how the system reacts to noise. We study its dependence on the system parameters, driving amplitude and driving frequency. Previous theoretical work has predicted that the barrier should display specific dependences, on these parameters, that are independent of the system. In this dissertation we test these predictions in our system, along with examining other features that systems possessing multiple stable states and driven out of equilibrium are expected to show. The system used in this study is a micro-electromechanical torsional oscillator. The device is fabricated using a standard commercial process that is reliable and customizable. The device provides a robust system that can be operated at different temperatures, pressures and in different resonant modes. When the damping of the system is small enough and the drive is large enough, the system displays multistable states. The micro-electromechanical torsional oscillators used in these studies are ideal apparatus for studying the transitions that occur between states of a multistable system when fluctuations are present.
