Steven Shaw

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Background: This paper describes an analytical study of a bandpass filter that is based on the dynamic response of electrostatically-driven MEMS oscillators. Method of Approach: Unlike most mechanical and electrical filters that rely on direct linear resonance for filtering, the MEM filter presented in this work employs parametric resonance. Results: While(More)
SUMMARY The purpose of this study is to understand the nonlinear dynamics of longitudinal ground vehicle traction. Specifically, single-wheel models of rubber-tired automobiles under straight-ahead braking and acceleration conditions are investigated in detail. Customarily, the forward vehicle speed and the rotational rate of the tire/wheel are taken as(More)
—Microelectromechanical oscillators utilizing nonin-terdigitated combdrive actuators have the ability to be parametri-cally excited, which leads to distinct advantages over harmonically driven oscillators. Theory predicts that this type of actuator, when dc voltage is applied, can also be used for tuning the effective linear and nonlinear stiffnesses of an(More)
This paper investigates the dynamic response of a class of electrostatically driven microelectromechanical (MEM) oscillators. The particular systems of interest are those which feature parametric excitation that arises from forces produced by fluctuating voltages applied across comb drives. These systems are known to exhibit a wide range of behaviors, some(More)
A numerical method for constructing non-linear normal modes (NNMs) for piecewise linear autonomous systems is presented. These NNMs are based on the concept of invariant manifolds, and are obtained using a Galerkin-based solution of the invariant manifold's non-linear partial differential equations. The accuracy of the constructed non-linear modes is(More)
Electrostatically-actuated resonant microbeam devices have garnered significant attention due to their geometric simplicity and broad applicability. Recently, some of this focus has turned to comb-driven microresonators with purely-parametric excitation, as such systems not only exhibit the inherent benefits of MEMS devices, but also a general improvement(More)
(1) Intravenous glucose tolerance tests have been carried out on 6 migraine sufferers on two occasions. The first study was carried out during a migraine attack and the second was performed in an attack-free period. The patients had fasted overnight and the investigations were carried out in the morning. Samples of venous blood were taken for measurement of(More)
This paper presents a general analysis and a concrete example of the catastrophic case of a discontinuity-induced bifurcation in so-called Filippov nonsmooth dynamical systems. Such systems are characterized by discontinuous jumps in the right-hand sides of differential equations across a phase space boundary and are often used as physical models of(More)
In this paper we describe the dynamics of MEMS oscillators that can be used as frequency filters. The unique feature of these devices is that they use parametric resonance, as opposed to the usual linear resonance, for frequency selection. However, their response in the parametric resonance zone has some undesirable features from the standpoint of filter(More)
This work reports the experimental demonstration of single input-single output, multianalyte detection and identification using a coupled array of microresonators. A prototype sensor with four frequency-mistuned microbeam sensors, each coupled to a common shuttle mass resonator, is presented. Tailored localized modes of vibration in this coupled system are(More)