Browse
Submit Data
Databases
API
Help

Dataset Information

21 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Ultrafast rotation of magnetically levitated macroscopic steel spheres.

ABSTRACT: Our world is increasingly powered by electricity, which is largely converted to or from mechanical energy using electric motors. Several applications have driven the miniaturization of these machines, resulting in high rotational speeds. Although speeds of several hundred thousand revolutions per minute have been used industrially, we report the realization of an electrical motor reaching 40 million rpm to explore the underlying physical boundaries. Millimeter-scale steel spheres, which are levitated and accelerated by magnetic fields inside a vacuum, are used as a rotor. Circumferential speeds exceeding 1000 m/s and centrifugal accelerations of more than 4 × 108 times gravity were reached. The results open up new research possibilities, such as the testing of materials under extreme centrifugal load, and provide insights into the development of future electric drive systems.

SUBMITTER: Schuck M

PROVIDER: S-EPMC5756664 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Ultrafast rotation of magnetically levitated macroscopic steel spheres.

Schuck Marcel M Steinert Daniel D Nussbaumer Thomas T Kolar Johann W JW

Science advances 20180105 1

Our world is increasingly powered by electricity, which is largely converted to or from mechanical energy using electric motors. Several applications have driven the miniaturization of these machines, resulting in high rotational speeds. Although speeds of several hundred thousand revolutions per minute have been used industrially, we report the realization of an electrical motor reaching 40 million rpm to explore the underlying physical boundaries. Millimeter-scale steel spheres, which are levi ...[more]

PMID: 29326976

Similar Datasets

The full phase space dynamics of a magnetically levitated electromagnetic vibration harvester.

Project description:We consider the motion of an electromagnetic vibrational energy harvester (EMVEH) as function of the initial position and velocity and show that this displays a classical chaotic dynamical behavior. The EMVEH considered consists of three coaxial cylindrical permanent magnets and two coaxial coils. The polarities of the three magnets are chosen in such a way that the central magnet floats, with its lateral motion being prevented by enclosion in a hollow plastic tube. The motion of the floating magnet, caused by e.g. environmental vibrations, induces a current in the coils allowing electrical energy to be harvested. We analyze the behavior of the system using a numerical model employing experimentally verified expressions of the force between the magnets and the damping force between the floating magnet and the coils. We map out the phase space of the motion of the system with and without gravity, and show that this displays a fractal-like behavior and that certain driving frequencies and initial conditions allow a large power to be harvested, and that more stable states than two exists. Finally, we show that at leasts fifth order polynomial approximation is necessary to approximate the magnet-magnet force and correctly predict the system behavior.

| S-EPMC8368241 | biostudies-literature

Magnetically remote-controlled optical sensor spheres for monitoring oxygen or pH.

Project description:Magnetic sensor macrospheres (MagSeMacs), i.e., stainless steel spheres coated with optical chemical sensors, are presented as an alternative to existing optical sensor patches and fiber-optical dip-probes. Such spheres can either be reversibly attached to the tip of an optical fiber (dip-probe) or trapped inside a vessel for read-out through the side wall. Moving the magnetic separator at the exterior enables measurements at varying positions with a single sensor. Moreover, the sensor's replacement is rapid and contactless. We measured dissolved oxygen or pH in stirred liquids, rotating flasks, and 24-well plates with a SensorDish-reader device for parallel cell culture monitoring. In these applications, MagSeMacs proved to be advantageous over conventional sensor patches and magnetic optical sensor particles because of their magnetism, spherical shape, reflectance, and size. These properties resulted in strong but reversible fixation, magnetic remote-controllability, short response times, high signal intensities, and simplified handling.

| S-EPMC2829951 | biostudies-literature

Macroscopic rotation of photon polarization induced by a single spin.

Project description:Entangling a single spin to the polarization of a single incoming photon, generated by an external source, would open new paradigms in quantum optics such as delayed-photon entanglement, deterministic logic gates or fault-tolerant quantum computing. These perspectives rely on the possibility that a single spin induces a macroscopic rotation of a photon polarization. Such polarization rotations induced by single spins were recently observed, yet limited to a few 10(-3) degrees due to poor spin-photon coupling. Here we report the enhancement by three orders of magnitude of the spin-photon interaction, using a cavity quantum electrodynamics device. A single hole spin in a semiconductor quantum dot is deterministically coupled to a micropillar cavity. The cavity-enhanced coupling between the incoming photons and the solid-state spin results in a polarization rotation by ± 6° when the spin is optically initialized in the up or down state. These results open the way towards a spin-based quantum network.

| S-EPMC4339913 | biostudies-literature

Magnetically levitated mesenchymal stem cell spheroids cultured with a collagen gel maintain phenotype and quiescence.

Project description:Multicellular spheroids are an established system for three-dimensional cell culture. Spheroids are typically generated using hanging drop or non-adherent culture; however, an emerging technique is to use magnetic levitation. Herein, mesenchymal stem cell spheroids were generated using magnetic nanoparticles and subsequently cultured within a type I collagen gel, with a view towards developing a bone marrow niche environment. Cells were loaded with magnetic nanoparticles, and suspended beneath an external magnet, inducing self-assembly of multicellular spheroids. Cells in spheroids were viable and compared to corresponding monolayer controls, maintained stem cell phenotype and were quiescent. Interestingly, core spheroid necrosis was not observed, even with increasing spheroid size, in contrast to other commonly used spheroid systems. This mesenchymal stem cell spheroid culture presents a potential platform for modelling in vitro bone marrow stem cell niches, elucidating interactions between cells, as well as a useful model for drug delivery studies.

| S-EPMC5460809 | biostudies-other

Coherent oscillations of a levitated birefringent microsphere in vacuum driven by nonconservative rotation-translation coupling.

Project description:We demonstrate an effect whereby stochastic, thermal fluctuations combine with nonconservative optical forces to break detailed balance and produce increasingly coherent, apparently deterministic motion for a vacuum-trapped particle. The particle is birefringent and held in a linearly polarized Gaussian optical trap. It undergoes oscillations that grow rapidly in amplitude as the air pressure is reduced, seemingly in contradiction to the equipartition of energy. This behavior is reproduced in direct simulations and captured in a simplified analytical model, showing that the underlying mechanism involves nonsymmetric coupling between rotational and translational degrees of freedom. When parametrically driven, these self-sustained oscillators exhibit an ultranarrow linewidth of 2.2 ?Hz and an ultrahigh mechanical quality factor in excess of 2 × 108 at room temperature. Last, nonequilibrium motion is seen to be a generic feature of optical vacuum traps, arising for any system with symmetry lower than that of a perfect isotropic microsphere in a Gaussian trap.

| S-EPMC7269642 | biostudies-literature

Ultrafast rotation in an amphidynamic crystalline metal organic framework.

Project description:Amphidynamic crystals are an emergent class of condensed phase matter designed with a combination of lattice-forming elements linked to components that display engineered dynamics in the solid state. Here, we address the design of a crystalline array of molecular rotors with inertial diffusional rotation at the nanoscale, characterized by the absence of steric or electronic barriers. We solved this challenge with 1,4-bicyclo[2.2.2]octane dicarboxylic acid (BODCA)-MOF, a metal-organic framework (MOF) built with a high-symmetry bicyclo[2.2.2]octane dicarboxylate linker in a Zn4O cubic lattice. Using spin-lattice relaxation 1H solid-state NMR at 29.49 and 13.87 MHz in the temperature range of 2.3-80 K, we showed that internal rotation occurs in a potential with energy barriers of 0.185 kcal mol-1 These results were confirmed with 2H solid-state NMR line-shape analysis and spin-lattice relaxation at 76.78 MHz obtained between 6 and 298 K, which, combined with molecular dynamics simulations, indicate that inertial diffusional rotation is characterized by a broad range of angular displacements with no residence time at any given site. The ambient temperature rotation of the bicyclo[2.2.2]octane (BCO) group in BODCA-MOF constitutes an example where engineered rotational dynamics in the solid state are as fast as they would be in a high-density gas or in a low-density liquid phase.

| S-EPMC5748175 | biostudies-literature

Ultrafast Synthesis of Multifunctional Submicrometer Hollow Silica Spheres in Microfluidic Spiral Channels.

Project description:We demonstrate a facile and ultrafast approach for the synthesis of multifunctional submicrometer hollow silica spheres (smHSSs) using microfluidic spiral channels with enhanced mixing performance, introduced by the transverse Dean flows cross the channel as a result of centrifugal effects. Formation of smHSSs is initiated by the hydrolysis of tetraethyl orthosilicate (TEOS) at the interface of two laminar reactant flows. Complete mixing of the flows further facilitates the subsequent condensation of hydrolyzed TEOS, which builds up the shell layer of smHSSs. The average size of the as-synthesized smHSSs is 804.7?nm, and the thickness of the shell layer is ~20?nm. Multifunctional smHSSs integrated with proteins, fluorescent dyes, quantum dots, and magnetic nanoparticles can be further produced via this general platform. Their applications in cell imaging, organic dye adsorption, and drug delivery are examined.

| S-EPMC5626769 | biostudies-literature

Ultrafast flavin/tryptophan radical pair kinetics in a magnetically sensitive artificial protein.

Project description:Radical pair formation and decay are implicated in a wide range of biological processes including avian magnetoreception. However, studying such biological radical pairs is complicated by both the complexity and relative fragility of natural systems. To resolve open questions about how natural flavin-amino acid radical pair systems are engineered, and to create new systems with novel properties, we developed a stable and highly adaptable de novo artificial protein system. These protein maquettes are designed with intentional simplicity and transparency to tolerate aggressive manipulations that are impractical or impossible in natural proteins. Here we characterize the ultrafast dynamics of a series of maquettes with differing electron-transfer distance between a covalently ligated flavin and a tryptophan in an environment free of other potential radical centers. We resolve the spectral signatures of the cysteine-ligated flavin singlet and triplet states and reveal the picosecond formation and recombination of singlet-born radical pairs. Magnetic field-sensitive triplet-born radical pair formation and recombination occurs at longer timescales. These results suggest that both triplet- and singlet-born radical pairs could be exploited as biological magnetic sensors.

| S-EPMC7301759 | biostudies-literature

Macroscopic conductivity of aqueous electrolyte solutions scales with ultrafast microscopic ion motions.

Project description:Despite the widespread use of aqueous electrolytes as conductors, the molecular mechanism of ionic conductivity at moderate to high electrolyte concentrations remains largely unresolved. Using a combination of dielectric spectroscopy and molecular dynamics simulations, we show that the absorption of electrolytes at ~0.3 THz sensitively reports on the local environment of ions. The magnitude of these high-frequency ionic motions scales linearly with conductivity for a wide range of ions and concentrations. This scaling is rationalized within a harmonic oscillator model based on the potential of mean force extracted from simulations. Our results thus suggest that long-ranged ionic transport is intimately related to the local energy landscape and to the friction for short-ranged ion dynamics: a high macroscopic electrolyte conductivity is thereby shown to be related to large-amplitude motions at a molecular scale.

| S-EPMC7109088 | biostudies-literature

Recoil-induced ultrafast molecular rotation probed by dynamical rotational Doppler effect.

Project description:Observing and controlling molecular motion and in particular rotation are fundamental topics in physics and chemistry. To initiate ultrafast rotation, one needs a way to transfer a large angular momentum to the molecule. As a showcase, this was performed by hard X-ray C1s ionization of carbon monoxide accompanied by spinning up the molecule via the recoil "kick" of the emitted fast photoelectron. To visualize this molecular motion, we use the dynamical rotational Doppler effect and an X-ray "pump-probe" device offered by nature itself: the recoil-induced ultrafast rotation is probed by subsequent Auger electron emission. The time information in our experiment originates from the natural delay between the C1s photoionization initiating the rotation and the ejection of the Auger electron. From a more general point of view, time-resolved measurements can be performed in two ways: either to vary the "delay" time as in conventional time-resolved pump-probe spectroscopy and use the dynamics given by the system, or to keep constant delay time and manipulate the dynamics. Since in our experiment we cannot change the delay time given by the core-hole lifetime τ, we use the second option and control the rotational speed by changing the kinetic energy of the photoelectron. The recoil-induced rotational dynamics controlled in such a way is observed as a photon energy-dependent asymmetry of the Auger line shape, in full agreement with theory. This asymmetry is explained by a significant change of the molecular orientation during the core-hole lifetime, which is comparable with the rotational period.

| S-EPMC6421426 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data