| During the last decade, we have witnessed that micro/nanomechanical 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.;In this study, we integrate geometric nonlinearity intentionally into micro/nanomechanical systems to enhance their performance by harnessing the nonlinear characteristics. For example, we originated the use of nonlinear instabilities to sense extremely small masses at femtogram-scale; 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; new design of a nonlinear atomic force microscopy (AFM) system to provide extremely high sensitivity to material properties. To realize nonlinear behavior, we exploited the remarkable properties of nanomaterials such as carbon nanotube and boron nitride nanotube, extreme stiffness in the axial direction and capacity to sustain large mechanical strains, through a unique fabrication technique of nanomaterial integration. |
