Dr. Jeffrey L. Kauffman Profile

KEYWORDS: Actuators, Dielectrics, Safety, Artificial muscles, Electrical breakdown, Chromium, Electrodes, Manufacturing, Dielectric elastomer actuators, Surgery

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Proceedings Article | 27 March 2018 Presentation + Paper

Tremor suppression controller for dielectric elastomer orthosis

Christopher Kelley, Jeffrey Kauffman

Proceedings Volume 10594, 105940U (2018) https://doi.org/10.1117/12.2296697

KEYWORDS: Actuators, Dielectrics, Linear filtering, Device simulation, Bandpass filters, Dielectric elastomer actuators, Kinematics, Active vibration control, Feedback control

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Proceedings Article | 15 March 2018 Paper

A synthetic shunt for piezoelectric-based state switching

Garrett Lopp, Jeffrey Kauffman

Proceedings Volume 10595, 105950A (2018) https://doi.org/10.1117/12.2296792

KEYWORDS: Switches, Switching, Capacitance, Modulation, Control systems, Signal processing, Digital signal processing, Aerospace engineering, Piezoelectric driven mechanisms

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Proceedings Article | 17 April 2017 Paper

Exploring dielectric elastomers as actuators for hand tremor suppression

Christopher Kelley, Jeffrey Kauffman

Proceedings Volume 10163, 1016322 (2017) https://doi.org/10.1117/12.2258735

KEYWORDS: Actuators, Dielectrics, Motion models, Control systems, Surgery, Brain, Electroluminescence, Kinematics, Manufacturing, System integration

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Proceedings Article | 11 April 2017 Paper

A continuous switching model for piezoelectric state switching methods

Garrett Lopp, Jeffrey Kauffman

Proceedings Volume 10164, 101641W (2017) https://doi.org/10.1117/12.2260392

KEYWORDS: Switching, Switches, Capacitance, Systems modeling, Vibration isolation, Motion analysis, Circuit switching, Relays, Motion models, Oscillators

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Proceedings Article | 15 April 2016 Paper

Control between coexistent attractors for optimal performance of a bistable piezoelectric vibration energy harvester

Daniel Geiyer, Jeffrey Kauffman

Proceedings Volume 9799, 97990I (2016) https://doi.org/10.1117/12.2222125

KEYWORDS: Energy harvesting, Control systems, Chaos, Oscillators, Algorithm development, Error analysis, Feedback control, MATLAB

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Proceedings Article | 15 April 2016 Paper

State switching in regions of high modal density

Garrett Lopp, Jeffrey Kauffman

Proceedings Volume 9799, 97991X (2016) https://doi.org/10.1117/12.2217923

KEYWORDS: Vibration control, Vibration isolation, Control systems, Systems modeling, Motion models, Motion analysis, Circuit switching, Analytical research, Aerospace engineering, Transducers

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Proceedings Article | 2 April 2015 Paper

Chaotic control of a piezomagnetoelastic beam for improved energy harvesting

Daniel Geiyer, Jeffrey Kauffman

Proceedings Volume 9431, 94310O (2015) https://doi.org/10.1117/12.2084048

KEYWORDS: Control systems, Chaos, Energy harvesting, Matrices, Oscillators, Complex systems, Systems modeling, Stochastic processes, Computing systems, Beam splitters

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Proceedings Article | 2 April 2015 Paper

Harvesting under transient conditions: harvested energy as a proxy for optimal resonance frequency detuning

Taylor Hynds, Jeffrey Kauffman

Proceedings Volume 9431, 94312B (2015) https://doi.org/10.1117/12.2084386

KEYWORDS: Switches, Switching, Resistance, Energy harvesting, Motion models, Control systems, Solids, Chemical elements, Motion analysis

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Piezoelectric-based vibration energy harvesting is of interest in a wide range of applications, and a number of harvesting schemes have been proposed and studied { primarily when operating under steady state conditions. However, energy harvesting behavior is rarely studied in systems with transient excitations. This paper will work to develop an understanding of this behavior within the context of a particular vibration reduction technique, resonance frequency detuning. Resonance frequency detuning provides a method of reducing mechanical response at structural resonances as the excitation frequency sweeps through a given range. This technique relies on switching the stiffness state of a structure at optimal times to detune its resonance frequency from that of the excitation. This paper examines how this optimal switch may be triggered in terms of the energy harvested, developing a normalized optimal switch energy that is independent of the open- and short-circuit resistances. Here the open- and short-circuit shunt resistances refer to imposed conditions that approximate the open- and short-circuit conditions, via high and low resistance shunts. These conditions are practically necessary to harvest the small amounts of power needed to switch stiffness states, as open-circuit and closed-circuit refer to infinite resistance and zero resistance, respectively, and therefore no energy passes through the harvesting circuit. The limiting stiffness states are then defined by these open- and short-circuit resistances. The optimal switch energy is studied over a range of sweep rates, damping ratios, and coupling coefficients; it is found to increase with the coupling coefficient and decrease as the sweep rate and damping ratio increase, behavior which is intuitive. Higher coupling means more energy is converted by the piezoelectric material, and therefore more energy is harvested in a given time; an increased sweep rate means resonance is reached sooner, and there will less time to harvest before the switch occurs; finally, increased damping nominally reduces the response of the system, therefore less mechanical energy is present and less energy will be harvested.

Proceedings Article | 3 April 2012 Paper

Optimal topology and experimental evaluation of PE materials for actively shunted GE polymer matrix fiber composite blades

Benjamin Choi, Kirsten Duffy, Jeffrey Kauffman, Nicholas Kray

Proceedings Volume 8345, 83452G (2012) https://doi.org/10.1117/12.917224

KEYWORDS: Actuators, Composites, Sensors, Control systems, Fluctuations and noise, Polymers, Feedback control, Amplifiers, Digital electronics, Finite element methods

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Proceedings Article | 27 April 2011 Paper

Performance of piezoelectric-based damping techniques for structures with changing excitation frequencies

Jeffrey Kauffman, George Lesieutre

Proceedings Volume 7977, 79770D (2011) https://doi.org/10.1117/12.880515

KEYWORDS: Switching, Switches, Resistance, Solids, Inductance, Analytical research, Motion models, Vibration control, Circuit switching, Vibrometry

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Showing 5 of 19 publications

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