scholarly journals Actuation of magnetoelastic membranes in precessing magnetic fields

2019 ◽  
Vol 116 (7) ◽  
pp. 2500-2505 ◽  
Author(s):  
Chase Austyn Brisbois ◽  
Mykola Tasinkevych ◽  
Pablo Vázquez-Montejo ◽  
Monica Olvera de la Cruz
Keyword(s):  
Molecular Dynamics ◽  
Magnetic Fields ◽  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Continuum Mechanics ◽  
Superparamagnetic Nanoparticles ◽  
Magnetic Interactions ◽  
Robotic Systems ◽  
Elastic Media ◽  
Dynamics Simulations

Superparamagnetic nanoparticles incorporated into elastic media offer the possibility of creating actuators driven by external fields in a multitude of environments. Here, magnetoelastic membranes are studied through a combination of continuum mechanics and molecular dynamics simulations. We show how induced magnetic interactions affect the buckling and the configuration of magnetoelastic membranes in rapidly precessing magnetic fields. The field, in competition with the bending and stretching of the membrane, transmits forces and torques that drives the membrane to expand, contract, or twist. We identify critical field values that induce spontaneous symmetry breaking as well as field regimes where multiple membrane configurations may be observed. Our insights into buckling mechanisms provide the bases to develop soft, autonomous robotic systems that can be used at micro- and macroscopic length scales.

scholarly journals Nonperiodic stochastic boundary conditions for molecular dynamics simulations of materials embedded into a continuum mechanics domain

2011 ◽  
Vol 134 (15) ◽  
pp. 154108 ◽  
Author(s):  
Mohammad Rahimi ◽  
Hossein Ali Karimi-Varzaneh ◽  
Michael C. Böhm ◽  
Florian Müller-Plathe ◽  
Sebastian Pfaller ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Boundary Conditions ◽  
Molecular Dynamics Simulations ◽  
Continuum Mechanics ◽  
Dynamics Simulations ◽  
Stochastic Boundary

scholarly journals Exploring the zone of anisotropy and broken symmetries in DNA-mediated nanoparticle crystallization

2016 ◽  
Vol 113 (38) ◽  
pp. 10485-10490 ◽  
Author(s):  
Matthew N. O’Brien ◽  
Martin Girard ◽  
Hai-Xin Lin ◽  
Jaime A. Millan ◽  
Monica Olvera de la Cruz ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Particle Size ◽  
Phase Transitions ◽  
Phase Space ◽  
Symmetry Breaking ◽  
Crystallization Behavior ◽  
Particle Surface ◽  
Rich Phase ◽  
Broken Symmetries ◽  
Dynamics Simulations

In this work, we present a joint experimental and molecular dynamics simulations effort to understand and map the crystallization behavior of polyhedral nanoparticles assembled via the interaction of DNA surface ligands. In these systems, we systematically investigated the interplay between the effects of particle core (via the particle symmetry and particle size) and ligands (via the ligand length) on crystallization behavior. This investigation revealed rich phase diagrams, previously unobserved phase transitions in polyhedral crystallization behavior, and an unexpected symmetry breaking in the ligand distribution on a particle surface. To understand these results, we introduce the concept of a zone of anisotropy, or the portion of the phase space where the anisotropy of the particle is preserved in the crystallization behavior. Through comparison of the zone of anisotropy for each particle we develop a foundational roadmap to guide future investigations.

scholarly journals Ultrafast imaging of spontaneous symmetry breaking in a photoionized molecular system

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Min Li ◽  
Ming Zhang ◽  
Oriol Vendrell ◽  
Zhenning Guo ◽  
Qianru Zhu ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Molecular System ◽  
Ultrafast Dynamics ◽  
Quantum Molecular Dynamics ◽  
Ultrafast Imaging ◽  
Jahn Teller ◽  
Jahn Teller Effect ◽  
Dynamics Simulations ◽  
Symmetry Space

AbstractThe Jahn-Teller effect is an essential mechanism of spontaneous symmetry breaking in molecular and solid state systems, and has far-reaching consequences in many fields. Up to now, to directly image the onset of Jahn-Teller symmetry breaking remains unreached. Here we employ ultrafast ion-coincidence Coulomb explosion imaging with sub-10 fs resolution and unambiguously image the ultrafast dynamics of Jahn-Teller deformations of $${{\rm{CH}}}_{4}^{+}$$ CH 4 + cation in symmetry space. It is unraveled that the Jahn-Teller deformation from C3v to C2v geometries takes a characteristic time of 20 ± 7 fs for this system. Classical and quantum molecular dynamics simulations agree well with the measurement, and reveal dynamics for the build-up of the C2v structure involving complex revival process of multiple vibrational pathways of the $${{\rm{CH}}}_{4}^{+}$$ CH 4 + cation.

Magneto-elastic coupling as a key to microstructural response of magnetic elastomers with flake-like particles

Soft Matter ◽  
2022 ◽  
Author(s):  
Alla Dobroserdova ◽  
Malte Schuemann ◽  
Dmitry Borin ◽  
Ekaterina V. Novak ◽  
Stefan Odenbach ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Magnetic Fields ◽  
Molecular Dynamics Simulations ◽  
Structural Transformations ◽  
Elastic Coupling ◽  
Dynamics Simulations ◽  
Magnetic Elastomers

Using the combination of experiment and molecular dynamics simulations, we investigate structural transformations in magnetic elastomers with NdFeB flake-like particles, caused by applied moderate magnetic fields. We explain why and...

scholarly journals Proposal to use superparamagnetic nanoparticles to test the role of cryptochrome in magnetoreception

2018 ◽  
Vol 15 (147) ◽  
pp. 20180587 ◽  
Author(s):  
Susannah Bourne Worster ◽  
P. J. Hore
Keyword(s):  
Spin Relaxation ◽  
Spin Dynamics ◽  
Spin Correlation ◽  
Neuronal Firing ◽  
Magnetic Sensors ◽  
Superparamagnetic Nanoparticles ◽  
Magnetic Interactions ◽  
Electron Spin Relaxation ◽  
Primary Sensor ◽  
Dynamics Simulations

Evidence is accumulating to support the hypothesis that some animals use light-induced radical pairs to detect the direction of the Earth's magnetic field. Cryptochrome proteins seem to be involved in the sensory pathway but it is not yet clear if they are the magnetic sensors: they could, instead, play a non-magnetic role as signal transducers downstream of the primary sensor. Here we propose an experiment with the potential to distinguish these functions. The principle is to use superparamagnetic nanoparticles to disable any magnetic sensing role by enhancing the electron spin relaxation of the radicals so as to destroy their spin correlation. We use spin dynamics simulations to show that magnetoferritin, a synthetic, protein-based nanoparticle, has the required properties. If cryptochrome is the primary sensor, then it should be inactivated by a magnetoferritin particle placed 12–16 nm away. This would prevent a bird from using its magnetic compass in behavioural tests and abolish magnetically sensitive neuronal firing in the retina. The key advantage of such an experiment is that any signal transduction role should be completely unaffected by the tiny magnetic interactions (≪ k B T ) required to enhance the spin relaxation of the radical pair.

scholarly journals Ultrafast imaging of spontaneous symmetry breaking in a photoionized molecular system

2020 ◽  
Author(s):  
Min Li ◽  
Ming Zhang ◽  
Oriol Vendrell ◽  
Zhenning Guo ◽  
Qianru Zhu ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Molecular System ◽  
Real Space ◽  
Ultrafast Dynamics ◽  
Quantum Molecular Dynamics ◽  
Ultrafast Imaging ◽  
Jahn Teller ◽  
Jahn Teller Effect ◽  
Dynamics Simulations

Abstract The Jahn-Teller effect is an essential mechanism of spontaneous symmetry breaking in molecular and solid state systems, and has far-reaching consequences in many fields. Up to now, to direct image the onset of Jahn-Teller symmetry breaking remains unreached. Employing ultrafast ion-coincidence Coulomb explosion imaging with sub-10 fs resolution, we unambiguously imaged the ultrafast dynamics of Jahn-Teller deformations of CH4+ cation in real space. It is unraveled that the Jahn-Teller deformation from C3v to C2v geometries takes a characteristic time of about 20 femtoseconds for this system. Classical and quantum molecular dynamics simulations agree well with the measurement, and reveal dynamics for the build-up of the C2v structure involving complex phasing process of multiple vibrational pathways of the CH4+ cation.

Modeling the Instability of Carbon Nanotubes: From Continuum Mechanics to Molecular Dynamics

2009 ◽  
Vol 1 (1) ◽  
Author(s):  
Wen Hui Duan ◽  
Qing Wang ◽  
Quan Wang ◽  
Kim Meow Liew
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Hybrid Model ◽  
Continuum Mechanics ◽  
Buckling Load ◽  
Multiwalled Carbon ◽  
Mechanics Model ◽  
Proposed Model ◽  
Potential Applications ◽  
Dynamics Simulations

A hybrid continuum mechanics and molecular mechanics model is developed in this paper to predict the critical strain, stress, and buckling load of the inelastic buckling of carbon nanotubes. With the proposed model, the beamlike and shell-like buckling behavior of carbon nanotubes can be analyzed in a unified approach. The buckling solutions from the hybrid model are verified from molecular dynamics simulations via the MATERIALS STUDIO software package and from available research findings. The existence of the optimum diameter, at which the buckling load reaches its maximum, and the correlation of the diameter with the length of carbon nanotubes, as predicted by Liew et al. (2004, “Nanomechanics of Single and Multiwalled Carbon Nanotubes,” Phys. Rev. B, 69(11), pp. 115429), are uncovered by the hybrid model. The simplicity and effectiveness of the proposed model are not only able to reveal the chiral and size-dependent buckling solutions for carbon nanotubes, but also enable a thorough understanding of the stability behavior of carbon nanotubes in potential applications.

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