Nonlinear Vibrations of Systems of MEMS Oscillators

Cornell University, Ithaca NY

Investigators

Abstract

Micro-scale and nano-scale electromechanical systems are extremely small (microscopic) devices which are used in sensing, navigation, clocks, printers, drug delivery, personal health care and other applications. For example, mobile phones contain multiple micro-scale sensors which function to determine which direction is up, to measure pressure and temperature, or to find magnetic North of the Earth. Many micro systems incorporate vibrating, or resonant, micron to nanometer scale flexible structures. The structural elements could be as simple as a cantilever beam etched from a silicon wafer, to complex three-dimensional architectures built from multiple layers of materials. As a result the "design space" for resonant micro-scale oscillators is tremendous. Making best use of this space requires a deep understanding of materials, fabrication, packaging, electronics, optics and mechanics. This project will focus on advancing knowledge of the nonlinear dynamics of single, pairs and arrays of resonators and oscillators. Discoveries enabled by the project will enlarge the design space and potentially lead to new technologies and devices. A new generation of scientists will be trained in this research. In addition to their training in traditional scientific disciplines, as a result of the international collaboration, they will develop an understanding and appreciation of the synergies of collaborative research that bridges geographical distances. The project will also result in undergraduates inspired through meaningful participation in research to excel in their studies and to pursue graduate degrees in STEM. The researchers will be encouraged to consider transfer technology developed from this research into existing or startup companies to promote economic development. The research will involve physical experiments on optically self-excited micron- down to nanometer-size scale devices, closely coupled to mathematical modeling and analysis. The experiments and models will start with an optically excited single oscillator, then build to pairs and arrays coupled through electrostatic or magnetic fields. Specific goals include: demonstrating locking of oscillator pairs and arrays, observing new phenomena, improving frequency stability, quantifying the relation of system response to key parameters and developing, analyzing and validating mathematical models that enhance understanding of observed phenomena and that underlie the design of MEMS systems. Through the experimental work and associated mathematical models the project will advance knowledge in the field of dynamics of nonlinear oscillators by addressing questions on the feasibility of and conditions for entrainment and locking of arrays of limit cycle oscillators physically realized as micron scale devices. Spanning the needed expertise in experimental mechanics, theory, design and fabrication, the project brings together an experienced research team from Cornell University, Tel Aviv University and the National Institute of Standards and Technology (NIST).