Seminar: Nonlinear Resonances at Micro/Nano-scales: Modeling, Intentional Implementation, and Applications

Abstract

During the last decade, we have witnessed that micro/nano-mechanical resonators have revolutionized fundamental and applied science. For example, nanosensors can be designed to sense physical quantities at the smallest scale, e.g., masses in atomic scale and forces as small as spin or hydrogen bonds; micro/nanoelectromechanical system (M/NEMS) based RF devices reach extremely high frequencies in their performance as filters, switches, and radio transmitters. Due to their small size and low damping, these devices often exhibit significant nonlinearity, which results in limiting the operational range when they are intended to operate in a linear regime. However, nonlinear resonance, easily realized in a micro/nanomechanical system, also opens up a whole new window for the study of nonlinear dynamics and, more importantly, the development of paradigm-shifting applications.

This talk will start with the discussion about the beneficial nonlinear characteristics utilizable at micro/nano-scale, and then mainly focus on how we can harness the unique nonlinear properties in the design of dynamic micro/nanomechanical systems. Subsequently, the speaker will demonstrate the efficacy of the concept of intentional nonlinearity for designing in the mociro/nano-scales with examples: the use of nonlinear instabilities to sense extremely small masses; the development of a tunable, broadband, nonlinear nanoresonator by employing carbon nanotube; the successful realization of intentional strong nonlinearity induced to a microsystem by a nanoscale attachment; the practical design to identify and measure the damping properties of an integrated nanomaterial; and the new design of a nonlinear atomic force microscopy (AFM) system to provide high sensitivity to material properties.

About the Speaker

Dr. Hanna Cho joins MAE as assistant professor in mechanical engineering this Autumn semester.  Previously, she was assistant professor of mechanical engineering at Texas Tech University (TTU) since 2013.  Cho earned BS and MS degrees in Mechanical Engineering from Yonsei University, South Korea in 2002 and 2004, respectively.  She received a PhD in Mechanical Science and Engineering at the University of Illinois at Urbana-Champaign (UIUC) in 2012, where she was a postdoctoral research associate working with UIUC’s Professor William P. King before joining TTU.

Cho’s research laboratory, the Micro/Nano Multiphysical Dynamics Laboratory, is focused on studying nonlinear dynamics in micro/nanomechanical systems to utilize beneficial nonlinear characteristics in developing novel Micro-Electro-Mechanical Systems (MEMS) and its nano-scale counterpart, Nano-Eleectro-Mechanical Systems (NEMS) applications such as sensing, imaging and energy harvesting; and multi-physical dynamics arising in atomic force microscopy (AFM) to advance state-of-the-art AFM.

Host TBD.