Dr. Paris von Lockette Profile

Dr. Paris von Lockette

at Univ of Maryland Baltimore County

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Author

Publications (6)

Proceedings Article | 22 March 2021 Presentation

Energy transduction versus design characteristics of a magnetoelastic peristalsis pump

Niknam Momenzadeh, Paris Von Lockette, Christian Bergen

Proceedings Volume 11589, 1158908 (2021) https://doi.org/10.1117/12.2585087

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Proceedings Article | 22 March 2021 Presentation + Paper

Modeling and simulations of a novel magnetorheological peristalsis blood pump

Niknam Momenzadeh, Paris Von Lockette

Proceedings Volume 11588, 115881I (2021) https://doi.org/10.1117/12.2585086

KEYWORDS: Blood, Modeling and simulation, Heart, Electromagnetism, Chemical elements

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Although heart disease is still the major cause of death in the world, cardiovascular mortality rate has decreased over the past years, which is mainly related to invention of different types of circulatory assist devices. Therefore, focus of recent studies lies at developing the cardiovascular assist technologies to further decrease mortality rate. Currently, impeller-driven and centrifugal pumping technologies are the state of art for artificial heart applications. These types of pumps are able to lengthen lives, however their operation produces blood damage(hemolysis) which makes them not suitable for long-term applications. A natural solution to the need to artificially pump blood over long time frames while accruing less blood damage can be found in peristaltic pumps. The peristaltic pump design discussed herein mimics the heart’s natural operation by using magnetoactive elastomers that respond to the presence of external electromagnetic fields. Utilization of a magnetorheological (MR) elastomer rather than rotating rollers could constitute a materials-based solution for solving the mechanical issue of hemolysis by avoiding impellers. Additionally, the mechanism produces desirable pulsatile flow. In this work, a magnetically driven peristalsis pumping mechanism is proposed and simulated using fully coupled finite element simulations in COMSOL Multiphysics. The primary goal of this work is to develop high(er) fidelity simulation of the working peristaltic pump in order to determine how design factors and the pumping mechanism affects hemolysis. Power law damage metrics, beyond basic flow shear stresses, were used to compare the hemolysis index in the proposed model with the results from previous works. Results show that blood damage at higher magnetic fields strength was larger than weaker applied magnetic field. Regardless of the magnetic field strength, average blood damage was higher approaching the outlet versus the inlet. In addition, this study shows the efficacy of the device geometry and means of operation which can be intermediate optima pointing toward possible optimization of peristaltic pump to increase the efficacy of the pump.

Proceedings Article | 29 March 2019 Presentation + Paper

Towards complex microarchitectural composites using multi-field processing

Md Al Masud, Anil Erol, Connor Edson, Zoubeida Ounaies, Paris von Lockette

Proceedings Volume 10968, 109680G (2019) https://doi.org/10.1117/12.2515259

KEYWORDS: Magnetism, Particles, Composites, Polymers, Dielectrics, Dielectrophoresis, Computer simulations, Nanocomposites

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In this study, we investigate the hierarchical microarchitecture formation of magnetic barium hexaferrite (BF) platelets in polydimethylsiloxane (PDMS) using electric and magnetic field assembly technique. First, external fields are applied to the colloidal solution to form the microstructure before curing the composites. After microstructure formation, the composites are thermally cured to freeze the microstructure. We investigate two different cases in this study-(1) magnetic field processed composites and (2) multi-field processed composites, which were processed under both magnetic and electric fields. We observe that macro-chains formed due to simultaneous application of electric and magnetic fields had a much higher length compared to the macro-chains formed due to just magnetic field. For both cases individual BHFs are found to be oriented in the direction of the external field. The analysis of SEM microstructures using ImageJ and MATLAB showed that at least two different levels of hierarchies are present in the microstructure for both cases, which are referred to as BHF stacks and micro-chains. From the experimental quantitative microstructure analysis, BHFs are found to be slightly better oriented (magnetic easy-axis direction in relation to the external field) at all scales for the electric and magnetic field processed composites compared to just the magnetic field processed composites. Magneto-electrohydrodynamics modeling of the polymer-particulate mixture predicts a similar behavior. Computational simulations are performed wherein particulates, subjected to both DEP forces resulting from an applied electric field, and magnetic dipole interactions in response to applied magnetic field, are allowed to form quasi-equilibrium structures before locking in a final structure to represent curing. Results from simulation confirms the finding on longer macro-chain formation similar to the experiment for the case of magnetic and electric fields compared to just magnetic field. Analysis of the microstructures from simulation also confirms that multiple levels of hierarchies are present in the composites’ microstructure for both cases. In future, quantifying the corresponding metrics at each level of hierarchy will help to better understand the microstructure and can be served as input to the model and also used to validate the model.

Proceedings Article | 29 March 2019 Presentation + Paper

Towards the design of electric field driven self-folding gripper

Saad Ahmed, Anil Erol, Wei Zhang, Jonathan Hong, Zoubeida Ounaies, Paris von Lockette, Mary Frecker

Proceedings Volume 10968, 109680P (2019) https://doi.org/10.1117/12.2514902

KEYWORDS: Actuators, Finite element methods, Electroactive polymers, Robotics, Electromechanical design, Polymers, Biomimetics

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Proceedings Article | 11 April 2017 Presentation + Paper

On the electric and magnetic alignment of magnetoactive barium hexaferrite-PDMS composites

Md Abdulla Al Masud, Corey Breznak, Paris von Lockette, Zoubeida Ounaies

Proceedings Volume 10165, 1016513 (2017) https://doi.org/10.1117/12.2263607

KEYWORDS: Magnetism, Composites, Dielectrophoresis, Polymers, Matrices, Optical microscopy, Scanning electron microscopy, Particles, Crystals, Electrodes

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Proceedings Article | 6 April 2006 Paper

Particle mixtures in magnetorheological elastomers (MREs)

Paris von Lockette, Jennifer Kadlowec, Jeong-Hoi Koo

Proceedings Volume 6170, 61700T (2006) https://doi.org/10.1117/12.658750

KEYWORDS: Particles, Magnetism, Iron, Composites, Barium, Nanoparticles, Silicon, Magnetostrictive materials, Anisotropy, Smart materials

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Showing 5 of 6 publications

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