Magnetic Levitation Research Articles

Analysis of the current status and development prospects of artificial hearts

Confronted with the rapid need for transplantable hearts, patients who need a heart transplant cannot receive the suitable configuration. Thus contributes to the development of artificial hearts, which can be created to substitute the old, the ill heart without waiting for transplantable hearts. Nowadays, this paper shows the public the artificial hearts. Through the extensive literature, it is clear that the development of artificial hearts. Dating back to the fifties of the last century, scientists began studying artificial hearts. Till now, China has created four generations of artificial hearts. They became more and more strong. The importance of the heart goes without saying, however, every year there are more and more heart failure patients. Paying more attention to the artificial hearts helps reduce the death rate of heart failures. Actually, although the patients can get the heart donors, they may not tolerate rejection. So research into artificial hearts more suitable for patients is imminent. This paper mainly introduces the fourth-generation artificial hearts (in fact, it is an improved version of the third generation), the magnetic levitation artificial heart attracts much more attention, and its composition and function have been greatly improved, reducing the difficulty of surgery. It is hoped that people can know much more about artificial hearts, and prospects for better methods to make better artificial hearts, and promote heart transplantations.

MagnetoShield: A Novel Open-Source Magnetic Levitation Benchmark Device for Mechatronics Education and Research.

This article presents an open-source device illustrating the well-known magnetic levitation experiment. The uniqueness of this particular device lies in its exceptionally small dimensions, affordability and availability, which makes it a perfect design for take-home experiments for education but it can also serve as a referential design for testing various control algorithms in research. In addition, this paper provides a comprehensive hardware design for reproducibility along with the detailed derivation of the mathematical model, system identification and validation. Moreover, the introduced hardware comes with an easy-to-use open-source application programming interface in C/C++ for the Arduino IDE, Simulink and CircuitPython. REXYGEN, another environment similar to Simulink, had also been used to demonstrate the capabilities of the MagnetoShield.

Density measurement and uncertainty evaluation of elemental and alloy liquids using electrostatic levitation

Liquid density is a crucial parameter in physical models, numerical simulations, and a key thermophysical property essential for understanding various physical phenomena. Although density measurements of liquid metals have been carried out with various methods, it is still hard to give consistent and precise results, particularly at high temperatures. In this study, we systematically perform the precise density measurements for 34 elemental and alloy liquids using electrostatic levitation (ESL). Through a comprehensive review of density data in the literature, we propose recommended density values for fourteen transition metal liquids. Notably, we observe significant discrepancies in density measurements between ESL and electromagnetic levitation (EML). After conducting careful uncertainty evaluation and error analysis, the discrepancies are attributed to the shape deformation of the liquids, which seriously influences the density and its temperature coefficient measurements. The present work not only provides high-quality density data but also helps to develop standards for archiving density datasets and improve the density measurements of high-temperature molten melts.

Viscosity of liquid Ni-based industrial alloys: experiments versus theory

The aim of this review is to succinctly review recent progress in experimental and theoretical investigation of the viscosity of binary and multicomponent Ni–Al-based industrial alloys, summarising the current state of knowledge of the topic. Viscosity data are important for simulation of microstructural evolution during solidification-related processes such as casting. Therefore, to obtain accurate predictions of defect-free microstructure, only reliable input data are required. Based on the synergy between experiment and theory, a review of the literature provides a critical evaluation of temperature- and composition-dependent viscosity data available from existing studies carried out over the last 60 years. The purpose of this review is threefold: to discuss container-based viscometer methods and alternative containerless processing via electromagnetic levitation during parabolic flights and on board the International Space Station; to analyse the viscosity models including their validation; and to refer to the first two points, to interpret the viscosity data.

Control of the maglev system with a low stiffness elastic track beam by pole assignment and a reduced order state observer

A maglev train system is an open loop unstable and strongly nonlinear system. Self-excited coupling vibration between the magnet and the track beam can occur even when the train is stationary. To avoid this, the track beam is generally designed with high stiffness, which directly increases the construction cost of the maglev line. In this research, a new control method for the maglev system with a low stiffness elastic track is proposed based on full state feedback theory and pole assignment theory. In the newly designed controller, track beam DOF is introduced into the control loop with the use of the reduced order state observer (ROSO) to make the control system have the ability to suppress track vibration actively, thus reducing the over dependence of the system stability on track properties. Effectiveness of the proposed control strategy is verified through experiments. Results show that it exhibits a better response compared to the traditional control method, with smaller fluctuations in levitation air gap and magnet acceleration. Furthermore, it can maintain system stability with relatively lower track stiffness, reducing the minimum requirements for track stiffness by 53.4% in the test.

Very strong levitation force and stability achieved with a large MgB2 superconductor disc

This rapid communication highlights a remarkable achievement obtained with a 120 mm diameter large cylindrical MgB2 bulk: the measurement of magnetic levitation forces up to 700 N at 20 K, levitation being stable up to levitation forces exceeding 400 N. The investigated sample, which has one of the largest dimensions reported in the literature, was fabricated using the unconventional spark plasma sintering technique. This method is known as one of the most efficient methods for producing dense MgB2 samples. This breakthrough holds significant potential for advancing high-performance levitation systems and superconducting applications, including high-speed transportation systems and magnetic bearings.

Design and optimization of H-type asymmetric magnetic suspension vibration absorber for ships

The active–passive hybrid vibration isolation technology emerges with the advancement of the requirements for ship vibration and noise reduction. Among these, the magnetic suspension damper based on magnetic suspension technology has received more attention. In this paper, the effects of magnetic pole area and control current on the magnetic flux density and suspension force are verified by establishing a magnetic suspension structure model and comparing and verifying the results carried out by combining the theoretical formulas and finite element simulation. By exploring the effect of the structure on the magnetic flux density and suspension force, a new H-type asymmetric magnetic suspension structure is proposed and simulated. The results show that the H-type asymmetric magnetic suspension structure is more successful at improving the suspension force while also widening the suspension force response interval and improving the performance of the magnetic suspension damper. In addition to offering a new design concept for the construction of ship vibration and noise reduction structures, this structural solution serves as a reference for the development of magnetic suspension dampers.

Fixed-time convergence of second-order nonlinear systems based on nonsingular fractional sliding mode

In this paper, a fixed-time convergence scheme for fractional sliding modes is proposed for nonlinear second-order systems. Firstly, a fixed-time fractional-order sliding mode surface is designed by combining the fixed-time theory with fractional-order sliding mode control, which has a faster convergence rate and less chattering. Secondly, the proposed sliding mode controller is applied to a class of second-order nonlinear systems subject to uncertainties and external perturbations to ensure that the system is globally robust fixed-time stable. Then, a continuous fractional order approach law is designed and the proposed sliding mode controller is shown to converge in fixed time by Lyapunov function and the convergence time is related to the choice of controller parameters. Finally, the fixed-time fractional-order sliding mode control strategy is applied to a second-order nonlinear magnetic levitation system system, and the simulation results verify the effectiveness of the proposed method.

Mohs micrographic surgery with magnet suspension of implantable cardioverter defibrillators.

Mohs micrographic surgery with magnet suspension of implantable cardioverter defibrillators.

Elucidation of the trapping characteristics of magnetic disk-like particles in a Hagen-Poiseuille flow via Brownian dynamics simulations (usage of multi-magnetic poles)

In the present study, we elucidate the behaviour of a suspension composed of magnetic disk-like particles that flow in a Hagen-Poiseuille flow in a gradient magnetic field and the trapping characteristics of the magnetic particles. To this end, we utilise multiple pairs of magnetic poles located outside the cylindrical system. Brownian dynamics simulations were performed in order to clarify the dependence of these characteristics on a variety of factors. It is seen that an increase in the magnetic field strength improves the trapping characteristics of disk-like particles if the influence of an applied magnetic field is sufficiently more dominant than that of a flow field and that of the magnetic particle-particle interaction. In the case of a strong magnetic particle-particle interaction, thin chain-like clusters are formed from an anchored particle trapped around a magnetic pole. If the two poles are sufficiently close to each other, an arch-type cluster is formed between them. We expect that this arch-type cluster may give rise to good trapping performance even in the presence of a strong flow field if the formation arises at a sufficiently large separation distance between the pair of magnetic poles. Highlights We have performed Brownian dynamics simulations for a magnetic disk-like particle suspension in a Hagen-Poiseuille flow. If the magnetic particle-particle interaction is sufficiently more dominant than the flow field, thin chain-like clusters are formed from an anchored particle. As the pole separation distance decreases, an arch-type configuration tends to be formed along the surface of the wall. This arch-type cluster that is formed between the pair of magnetic poles may be expected to improve the trapping characteristics depending on the pole separation distance.

An observer for magnetic levitation system control based on a coefficient diagram method and backstepping

An observer for magnetic levitation system control based on a coefficient diagram method and backstepping

Density, viscosity, and CO2 solubility in ether-functionalized phosphonium-based bis(trifluoromethanesulfonyl)amide ionic liquids

We measured the densities and viscosities of two ionic liquids, triethyl(methoxymethyl)phosphonium bis(trifluoromethanesulfonyl)amide ([P222(1O1)][TFSA]) and triethyl(2-methoxyethyl)phosphonium bis(trifluoromethanesulfonyl)amide ([P222(2O1)][TFSA]), at atmospheric pressure and 273.15–363.15 K. The high-pressure density at the pressures up to 50 MPa was also measured at 298.15–353.15 K. Meanwhile, CO2 solubility in these phosphonium-based ionic liquids was determined using a magnetic suspension balance at 303.15–333.15 K and pressures up to 6 MPa. The experimental density and viscosity at atmospheric pressure were fitted using quadratic and Vogel-Fulcher-Tammann equations, respectively. The high-pressure density was fitted using the Tait equation and Sanchez-Lacombe equation of state. The properties of the two ether-functionalized ionic liquids were compared to those of triethylpentylphosphonium bis(trifluoromethanesulfonyl)amide [P2225][TFSA]. The density at atmospheric pressure increased in the order [P2225][TFSA] < [P222(2O1)][TFSA] < [P222(1O1)][TFSA]. The introduction of the ether group effectively reduced viscosity in the following order: [P222(1O1)][TFSA] < [P222(2O1)][TFSA] < [P2225][TFSA]. The CO2 solubilities in [P222(1O1)][TFSA] and [P222(2O1)][TFSA] were slightly lower than those in [P2225][TFSA]. In contrast, the molality of CO2 (m1) increased in the order [P2225][TFSA] < [P222(2O1)][TFSA] < [P222(1O1)][TFSA]. Ether functionalized phosphonium-based cations are effective in enhancing the physical absorption of CO2, particularly the molality of CO2.

A hybrid energy harvester inspired by bionic flapping wing structure based on magnetic levitation.

A hybrid energy harvester based on magnetic levitation is inspired by the structure of the flapping wing, which consists of two parts: one is a flapping wing structure mounted with a piezoelectric sheet, which can achieve piezoelectric energy harvesting; the other is an intermediate muscle unit, which is vertically arranged by three groups of permanent magnets to achieve magnetic levitation electromagnetic energy harvesting. An electromechanical-electromagnetic coupling model of this harvester is established based on electromechanical coupling characteristics. The simulation analysis can evaluate the magnetic field distribution and nonlinear magnetic properties and also analyze its effects on the output performance. Several experiments are designed to verify the effectiveness of the hybrid energy harvesting structure and to check the influence of the number of magnets on the output power. The maximum output power of the proposed structure can generate 13.61 mW at 4.5Hz excitation.

Utilization of G-Programming Language for Educational Control Application: Case Study of Magnetic Levitation of Elastic Beam

This paper explores the application of G-Programming tools in designing and implementing traditional control algorithms for a magnetic levitation system using LabVIEW. The study focuses on the challenges of managing this fast, dynamic, and sensitive system, demonstrating the effcacy of LabVIEW G-Programming for control education. PID and Lead-Lag controllers are developed within LabVIEW, featuring tuning and optimization capabilities through Virtual Instruments of the control design and simulation toolkit. The research provides insights into the system’s modelling, control action testing, dynamic simulation, and real-time control law deployment, concluding that G-Programming effectively facilitates experiential learning and validation in control systems engineering.

Magnetic Levitation Remote Control Laboratory Based on Matlab and Websockets

This work proposes a novel architecture for constructing remote laboratories, employing modular building blocks: Matlab/Simulink software for control system design and simulation, WebSocket communication technology for continuous data exchange, and a front-end application developed using the Angular framework. To facilitate WebSocket communication on the Matlab server side, the MatlabWebSocket library is implemented. Beyond the Angular framework, interactivity within the remote laboratory is further enhanced through 3D visualization of the controlled system using a Three.js based library.These combined technologies are applied in the development of a remote laboratory for a fast, unstable, and nonlinear magnetic levitation system. The laboratory allows users to remotely set desired values and control parameters for experiments, while also providing continuous data visualization in various forms, including numerical readouts, graphs, and 3D animations. This approach demonstrates the effectiveness of the proposed architecture for building remote laboratories for complex systems.

Determination of skin friction on a rotating sphere in magnetic levitation

Determination of skin friction on a rotating sphere in magnetic levitation

Improvement of Measurement Performance in Density Through Magnetic Levitation Using Asymmetrical Cylindrical Magnets

Improvement of Measurement Performance in Density Through Magnetic Levitation Using Asymmetrical Cylindrical Magnets

Method for Large-scale Production of hIPSC Spheroids.

Stem cell spheroids are rapidly becoming essential tools for a diverse array of applications ranging from tissue engineering to 3D cell models and fundamental biology. Given the increasing prominence of biotechnology, there is a pressing need to develop more accessible, efficient, and reproducible methods for producing these models. Various techniques such as hanging drop, rotating wall vessel, magnetic levitation, or microfluidics have been employed to generate spheroids. However, none of these methods facilitate the easy and efficient production of a large number of spheroids using a standard 6-well plate. Here, we present a novel method based on pellet culture (utilizing U-shaped microstructures) using a silicon mold produced through 3D printing, along with a detailed and illustrated manufacturing protocol. This technique enables the rapid production of reproducible and controlled spheroids (for 1× 106 cells, spheroids = 130 ± 10 μm) from human induced pluripotent stem cells (hIPSCs) within a short time frame (24 h). Importantly, the method allows the production of large quantities (2 × 104 spheroids for 1 × 106 cells) in an accessible and cost-effective manner, thanks to the use of a reusable mold. The protocols outlined herein are easily implementable, and all the necessary files for the method replication are freely available. Key features • Provision of 3D mold files (STL) to produce silicone induction device of spheroids using 3D printing. • Cost-effective, reusable, and autoclavable device capable of generating up to 1.2 × 104 spheroids of tunable diameters in a 6-well plate. • Spheroids induction with multiple hIPSC cell lines. • Robust and reproducible production method suitable for routine laboratory use.

Base pressure fluctuations on levitated freestream-aligned circular cylinder

Base pressure fluctuations associated with the large-scale wake structures behind a freestream-aligned circular cylinder and aerodynamic force fluctuations related to them are experimentally investigated in the wind tunnel tests. Measurements at ReD=6.97×104 and 1.04×105 were conducted using pressure-sensitive paint (PSP) and a magnetic suspension and balance system (MSBS) for creating a supportless condition. The obtained pressure fields were mainly analyzed by a modal decomposition combining azimuthal Fourier decomposition and proper orthogonal decomposition (POD). The pressure fluctuations caused by large-scale vortex shedding were observed from the results of frequency analysis for mode coefficients. The states of the fluctuations were classified into three patterns, which are anticlockwise/clockwise circular and flapping patterns. These patterns have been observed in the previous studies for velocity fluctuations in the wake of a freestream-aligned circular cylinder. The conditional sampling analysis revealed that the trend in the amplitude of the pressure fluctuations is different by the state, and the flapping pattern causes a large pressure difference across the cylinder axis. Furthermore, the relationship between the antisymmetric pressure fluctuations and lift fluctuations, which act in the lateral direction of the cylinder, is confirmed.

Investigation of a Wind Tunnel System for Spinning Body Using Magnetic Suspension

Investigation of a Wind Tunnel System for Spinning Body Using Magnetic Suspension