Nonlinear dynamics in nanomechanical systems
Abstract
This thesis examines the nonlinear dynamic behavior of two different nanomechanical systems. The first system examined is a model of friction force microscopy; this model is prototypical of single asperity friction. With this model, the resonant response of a single-degree-of-freedom model is examined. Next, the effects of tip compliance, which models high aspect ratio tips, are considered. A variety motions are possible within this model, namely multiple atom stick-slip which may be capable of reducing frictional forces by appropriate engineering of surfaces. The second system examined in this thesis is a suspended carbon nanotube resonator. These devices are capable of very high frequency operation as well as reduced power consumption and decreased size. However, a variety of issues must be considered for their practical implementation in useful devices. This thesis addresses several of these issues in suspended carbon nanotube resonators, namely: experimental fabrication and characterization, models exploring nonplanar, whirling motions, and models exploring physically consistent forcing by including both parametric excitation and DC bias voltage. This thesis demonstrates that modeling structural and forcing nonlinearities is critical in predicting device performance. Only when the relevant nonlinearities are included in the model can the salient response features be predicted. More challenging is leveraging these nonlinear response features to improve operation metrics.
Degree
Ph.D.
Advisors
Rhoads, Purdue University.
Subject Area
Mechanics|Mechanical engineering|Condensed matter physics
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