SST: Dynamics of Microbeam Sensor Arrays

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

1 Project Summary: SST: Nonlinear Dynamics of Microbeam Systems Intellectual Merit: In the proposed study we aim to improve the operation of SPM cantilevers in air and vacuum by investigating important effects due to nonlinearity, shape, and coupling to nearby cantilevers. Simultaneous operations of microbeam arrays can lead to significantly increased throughput in applications including chemical and force sensors, imaging, and data storage. These effects can lead to dynamically interesting phenomena, including localization and parametric instability. By understanding these effects, design and operation can be proposed which allow the cantilevers to synchronize, leading to sensor enhancement. This proposed work will involve modeling, analysis, and experimentation. In this work the nonlinear response of microbeams near resonance will be investigated in detail and features will be mapped out that are important for performance. The analytical investigations will focus on perturbation, symmetry, and phase reduction techniques applied to weakly nonlinear models for microbeams, which will allow one to predict the response near resonance. Experimental work will be used for parameter identification, model verification, and to explore operating regimes suggested by the analysis. The work will focus on the response of individual microbeams and one-dimensional arrays of microbeams, such as those being developed for increased throughput of chemical sensors. These arrays are composed of several nearly identical beams that are weakly coupled to their nearest neighbors. Systems with these general characteristics are known to experience instabilities and localized responses, wherein synchronization is lost and the vibration energy is concentrated in a small subset of beams. The analytical part of the work will concentrate on how these instabilities and localization are influenced by system and excitation parameters, and the manner in which they affect overall performance of the sensor. In addition, analytical models that employ intentional patterns of mistuning will be considered, which are known to minimize the effects of instability and localization. The experimental work will be used to guide and confirm the analysis, and to test systems that are designed to operate in a synchronous manner. Broader Impacts: An integrated educational plan has been proposed which integrates outreach with graduate education. Specifically, the goal would be to incorporate demonstrations and explanations of observable phenomena that can be accounted for through an understanding of nonlinear vibrations and dynamics, as well as topics from microscale and nanoscale engineering, to existing outreach programs. The mechanics principles behind simple cantilever sensors can be used to illustrate how simple physics principles are used to develop sensors, and show practical, exciting application of science. At UCSB these programs will be developed through collaborations with local teachers. At least one of these relationships has already been solidified with a teacher at Santa Barbara Jr. High. At MSU, this outreach would occur via the MSU High School Engineering Institute, which targets secondary school students and actively encourages participation in the engineering sciences. Broader impact in graduate education and technology transfer will be achieved in part through partnerships with Veeco, a local company. Veeco has a long-standing relationship with UCSB. Veeco is currently a member of the California Nanosystems institute, and has funded graduate student interns at Veeco, including one from the PI's group. Veeco is interested in the technology we plan to study in this effort, and will allow students to utilize equipment unavailable at UCSB. Teaming: The proposed effort is a collaboration between Kimberly Turner (UCSB), Steven Shaw (MSU), and Jeffrey Moehlis (UCSB), and will be carried out at their home institutions. The students and PIs on both teams will be involved in all aspects of the project, keeping up to date via electronic communication and by regular visits by the MSU group to the facilities at UCSB.