Multilayer, Stacked Spiral Copper Inductors on Silicon with Micro-Henry Inductance Using Single-Level Lithography

We present copper structures composed of multilayer, stacked inductors (MLSIs) with tens of micro-Henry inductance for use in low frequency (sub 100 MHz), power converter technology. Unique to this work is the introduction of single-level lithography over the traditional two-level approach to create each inductor layer. The result is a simplified fabrication process which results in a reduction in the number of lithography steps per inductor (metal) layer and a reduction in the necessary alignment precision. Additionally, we show that this fabrication process yields strong adhesion amongst the layers, since even after a postprocess abrasion technique at the inner diameter of the inductors, no shearing occurs and connectivity is preserved. In total, three separate structures were fabricated using the single-level lithography approach, each with a three-layered, stacked inductor design but with varied geometries. Measured values for each of the structures were extracted, and the following results were obtained: inductance values of 24.74, 17.25, and 24.74 μH, self-resonances of 9.87, 5.72, and 10.58 MHz, and peak quality factors of 2.26, 2.05, and 4.6, respectively. These values are in good agreement with the lumped parameter model presented.

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Dynamic Stability of a Water Brake Dynamometer

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2818092 ◽

1998 ◽

Vol 120 (1) ◽

pp. 89-96 ◽

Cited By ~ 1

Author(s):

R. A. Van den Braembussche ◽

H. Malys

Keyword(s):

High Frequency ◽

Low Frequency ◽

Lumped Parameter Model ◽

Stable Operation ◽

Pressure Oscillations ◽

Lumped Parameter ◽

Flow Oscillations ◽

Brake Dynamometer ◽

Low Torque ◽

Frequency Variations

A lumped parameter model to predict the high frequency pressure oscillations observed in a water brake dynamometer is presented. It explains how the measured low frequency variations of the torque are a consequence of the variation in amplitude of the high frequency flow oscillations. Based on this model, geometrical modifications were defined, aiming to suppress the oscillations while maintaining mechanical integrity of the device. An experimental verification demonstrated the validity of the model and showed a very stable operation of the modified dynamometer even at very low torque.

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Nonlinear Oscillations of a Particle in the Plane Under Longitudinal End Excitation

Volume 5: 19th Biennial Conference on Mechanical Vibration and Noise, Parts A, B, and C ◽

10.1115/detc2003/vib-48604 ◽

2003 ◽

Author(s):

Rajesh K. Jha ◽

Robert G. Parker

Keyword(s):

Nonlinear Oscillations ◽

Low Frequency ◽

Period Doubling ◽

Lumped Parameter Model ◽

Lumped Parameter ◽

Parametric Resonances ◽

Jump Phenomena ◽

Route To Chaos ◽

Chaotic Nature ◽

Two Degree Of Freedom

We study the forced vibrations of a two degree of freedom lumped parameter model of a belt span under longitudinal excitation. The belt inertia is modelled as a particle and the belt elasticity is modelled by two identical linear springs. Numerical integration is used to calculate free responses and perform frequency and amplitude sweeps. Frequency sweep results indicate parametric resonances, jump phenomena, sub- and super-harmonic responses, quasiperiodicity and chaos. Amplitude sweep at a low frequency shows bifurcations of limit cycles and the period doubling route to chaos. Poincare sections are computed to show the chaotic nature of the responses.

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Mathematical Model of Suspension Seat-Person Exposed to Vertical Vibration for Off-Road Vehicles

International Journal of Automotive and Mechanical Engineering ◽

10.15282/ijame.16.2.2019.22.0509 ◽

2019 ◽

Vol 16 (2) ◽

pp. 6773-6782

Author(s):

S. Aisyah Adam ◽

N. A. A. Jalil ◽

K. A. Md Razali ◽

Y. G. Ng ◽

M. F. Aladdin

Keyword(s):

Human Body ◽

Degrees Of Freedom ◽

Low Frequency ◽

Coupled System ◽

Vertical Vibration ◽

Lumped Parameter Model ◽

Model Parameters ◽

Road Vehicles ◽

Lumped Parameter ◽

Variable Function

Off-road drivers are exposed to a high magnitude of vibration at low frequency (0.5-25Hz), that can cause harm and possibly attribute to musculoskeletal disorder, particularly low-back pain. The suspension seat is commonly used on an off-road condition to isolate the vibration transmitted to the human body. Nevertheless, the suspension seat modelling that incorporates the human body is still scarce. The objective of this study is to develop a mathematical modelling to represent the suspension seat-person for off-road vehicles. This paper presents a three degrees-of-freedom lumped parameter model. A curve-fitting method is used for parameter identification, which includes the constraint variable function (fmincon()) from the optimisation toolbox of MATLAB(R2017a). The model parameters are optimised using experimentally measured of suspension seat transmissibility. It was found that the model provides a reasonable fit to the measured suspension seat transmissibility at the first peak of resonance frequency, around 2-3 Hz. The results of the study suggested that the human body forms a coupled system with the suspension seat and thus affects the overall performance of the suspension system. As a conclusion, the influence of the human body should not be ignored in the modelling, and a three-degrees degree-of-freedom lumped parameter model provides a better prediction of suspension seat transmissibility. This proposed model is recommended to predict vibration transmissibility for off-road suspension seat.

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Modeling and parametric study of a force-amplified compressive-mode piezoelectric energy harvester

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x16642536 ◽

2016 ◽

Vol 28 (3) ◽

pp. 357-366 ◽

Cited By ~ 17

Author(s):

Zhengbao Yang ◽

Jean Zu ◽

Jun Luo ◽

Yan Peng

Keyword(s):

Power Generation ◽

Energy Harvester ◽

Low Frequency ◽

Lumped Parameter Model ◽

Small Scale ◽

Energy Harvesters ◽

Piezoelectric Energy ◽

Multi Stage ◽

Lumped Parameter ◽

Compressive Mode

Piezoelectric energy harvesters have great potential for achieving inexhaustible power supply for small-scale electronic devices. However, the insufficient power-generation capability and the narrow working bandwidth of traditional energy harvesters have significantly hindered their adoption. To address these issues, we propose a nonlinear compressive-mode piezoelectric energy harvester. We embedded a multi-stage force amplification mechanism into the energy harvester, which greatly improved its power-generation capability. In this article, we describe how we first established an analytical model to study the force amplification effect. A lumped-parameter model was then built to simulate the strong nonlinear responses of the proposed energy harvester. A prototype was fabricated which demonstrated a superior power output of 30 mW under an excitation of 0.3 g ([Formula: see text] m/s2). We discuss at the end the effect of geometric parameters that are influential to the performance. The proposed energy harvester is suitable to be used in low-frequency weak-excitation environments for powering wireless sensors.

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Design and test of a torsional vibration absorber in series with a planetary gearset

Journal of Vibration and Control ◽

10.1177/1077546320943801 ◽

2020 ◽

pp. 107754632094380

Author(s):

Luke Jurmu ◽

Darrell Robinette ◽

Jason Blough ◽

Mark Gehringer

Keyword(s):

Torsional Vibration ◽

Low Frequency ◽

Large Mass ◽

Lumped Parameter Model ◽

Vibration Absorber ◽

Torsional Mode ◽

Lumped Parameter ◽

Modes Of Vibration ◽

In Series ◽

Tuning Frequency

Traditional vibration absorbers have not often been a practical solution for attenuating low frequency drivetrain modes of vibration because of the combination of the large mass and inertia and/or low stiffness, required to tune to the desired frequency. With the goal of reducing the inertia and size of a torsional vibration absorber, a unique vibration absorber was developed. Using a planetary gearset, the effective inertia of the absorber was increased without changing its physical mass, and a torsional mode below 30 Hz was successfully attenuated with physically realizable inertia and stiffness parameters. By reducing the tuned mass, the total volume claimed by the vibration absorber and planetary gearset was up to three times less than an equivalent traditional vibration absorber. A lumped parameter torsional model was developed to determine the optimal configuration of the planetary gearset input, output, and absorber inertia as well as a method to predict the optimal tuning frequency of the planetary torsional vibration absorber. A drivetrain dynamometer setup which emulates a two-degree-of-freedom torsional system was used to experimentally test and validate the performance of two planetary torsional vibration absorber prototypes built based upon the results of the lumped parameter model. The dynamometer setup was designed to have a first torsional mode around 20 Hz in which the planetary torsional vibration absorber was designed to attenuate. Based upon the experimental results of the planetary torsional vibration absorber, a reduction of over 20 dB was achieved.

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Control of Flow Limitation in Flexible Tubes

Journal of Mechanical Design ◽

10.1115/1.4034672 ◽

2016 ◽

Vol 139 (1) ◽

Cited By ~ 1

Author(s):

Ruo-Qian Wang ◽

Teresa Lin ◽

Pulkit Shamshery ◽

Amos G. Winter

Keyword(s):

Flow Rate ◽

Control Flow ◽

Lumped Parameter Model ◽

Needle Valve ◽

Flow Limitation ◽

Lumped Parameter ◽

Inner Diameter ◽

Series Of Experiments ◽

Flexible Tubes ◽

Tube Geometry

This paper proposes a new Starling resistor architecture to control flow limitation in flexible tubes by introducing a needle valve to restrict inlet flow. The new architecture is able to separately control the activation pressure and the flow rate: The tube geometry determines the activation pressure and the needle valve determines the flow rate. A series of experiments were performed to quantify the needle valve and the tube geometry's effect on flow limitation. The examined factors include the inner diameter, the length, and the wall thickness. A lumped-parameter model was developed to capture the magnitude and trend of the flow limitation, which was able to satisfactorily predict Starling resistor behavior observed in our experiments.

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