Collaborative Research: Noisy Nonlinear Microscale Oscillators for Novel Applications

The goals of the proposed project are to develop a fundamental understanding of the interplay of noise and nonlinearity in micro- and nano-scale electromechanical system (M/NEMS) resonators, and to exploit this knowledge for the development of novel applications in the areas of sensing and signal processing. The fundamental work will be geared towards the generation of predictive analytical and computational tools that can be employed in device development, and these results will be used to design M/NEMS devices with unprecedented selectivity and sensitivity. The methods to be employed include those from the fields of nonlinear dynamical systems, the theory of fluctuations, and experimental methods for M/NEMS. Fluctuations in M/NEMS arise from thermal and/or quantum noise, or can be intentionally injected from external sources. Even small noise can induce large changes in nonlinear system response, resulting in high sensitivity to external signals or environmental conditions. By careful tuning of the system parameters and inputs (periodic and/or noise), and with an understanding of how parameter changes affect switching, one can attain dramatic, predictable, and measurable changes in the system response. For sensor applications these changes are tied to environmental sources, while for signal processing the changes are linked to the modulation of an external signal. This proposal develops systematic methods for predicting these quantities for nonlinear M/NEMS resonators, based on the theory of noise-activated switching. The results from the analysis will guide the experimental efforts, which will implement the proposed techniques in novel schemes for mass and magnetic field detection, and for amplification of targeted signal quantities.

The broader impacts of the proposed research include the cross-disciplinary collaboration and training of students between physics and engineering, and the integration of existing computational, analytical, and experimental techniques to develop new concepts and approaches for sensing and signal processing. The fundamental aspects of the work also have potential applicability in other fields in which there is inherent interplay between nonlinearity and fluctuations, such as epidemiology and other areas of quantitative biology. In addition, the PIs will actively participate in outreach programs to high school students, including the High School Engineering Institute at Michigan State University and the Student Science Training Program at the University of Florida. The general topics of micro-and nano-technology, and the applications developed in the proposed work, will be used to help promote science and engineering to high school students in these programs.