scholarly journals Wireless Walking Paper Robot Driven by Magnetic Polymer Actuator

Actuators ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 109
Author(s):  
Han-Sol Lee ◽  
Yong-Uk Jeon ◽  
In-Seong Lee ◽  
Jin-Yong Jeong ◽  
Manh Cuong Hoang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Particles ◽  
Magnetic Flux Density ◽  
Small Scale ◽  
Soft Robot ◽  
Magnetically Actuated ◽  
Element Simulation ◽  
Walking Motion ◽  
Polymer Actuator ◽  
Magnetic Microparticle

Untethered small-scale soft robots have been widely researched because they can be employed to perform wireless procedures via natural orifices in the human body, or other minimally invasive operations. Nevertheless, achieving untethered robotic motion remains challenging owing to the lack of an effective wireless actuation mechanism. To overcome this limitation, we propose a magnetically actuated walking soft robot based on paper and a chained magnetic-microparticle-embedded polymer actuator. The magnetic polymer actuator was prepared by combining Fe3O4 magnetic particles (MPs, diameter of ~50 nm) and silicon that are affected by a magnetic field; thereafter, the magnetic properties were quantified to achieve proper force and optimized according to the mass ratio, viscosity, and rotational speed of a spin coater. The fabricated polymer was utilized as a soft robot actuator that can be controlled using an external magnetic field, and paper was employed to construct the robot body with legs to achieve walking motion. To confirm the feasibility of the designed robot, the operating capability of the robot was analyzed through finite element simulation, and a walking experiment was conducted using electromagnetic actuation. The soft robot could be moved by varying the magnetic flux density and on–off state, and it demonstrated a maximum moving speed of 0.77 mm/s. Further studies on the proposed soft walking robot may advance the development of small-scale robots with diagnostic and therapeutic functionalities for application in biomedical fields.

Transport of Magnetic Particles Under a Uniform Magnetic Field in Microchannels

2013 ◽  
Author(s):  
Gui-Ping Zhu ◽  
Nam-Trung Nguyen
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Flux ◽  
Flux Density ◽  
Uniform Magnetic Field ◽  
Magnetic Particles ◽  
Independent Solution ◽  
Magnetic Flux Density ◽  
Mixing Efficiency ◽  
Water Mixture

This paper reports the numerical and experimental investigation on magnetic particle concentration in a uniform magnetic field. The flow system consists of water-based ferrofluid and glycerol/DI water mixture streams. Two regimes were observed with spreading and mixing phenomena. With a low magnetic field strength, the spread of magnetic particles is caused by improved diffusion migration. With a relatively high field strength, instability at the interface would occur due to the mismatch in magnetization of the fluid streams. The transport of magnetic particles is induced by chaotic mixing of the fluids caused by a secondary flow. The mixing phenomena are characterized by magnetic flux density. For configuration with flow rate and viscosity ratio (between diamagnetic and magnetic streams) being set at 1 and 0.5, the mixing efficiency analyzed based on magnetic particles concentration increases approximately by 0.3 at around 3.5 mT. This value of magnetic flux density indicates the requirement on instability inception. The mixing efficiency increases with magnetic flux density increases further. Complete mixing can be achieved with a magnetic flux density at around 10 mT. The magnetic approach offers a wireless, heat-free and pH-independent solution for a lab-on-a-chip system.

scholarly journals Observations of solar small-scale magnetic flux-sheet emergence

2019 ◽  
Vol 622 ◽  
pp. L12 ◽  
Author(s):  
C. E. Fischer ◽  
J. M. Borrero ◽  
N. Bello González ◽  
A. J. Kaithakkal
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Flux Density ◽  
Large Scale ◽  
Magnetic Loop ◽  
Field Vector ◽  
Magnetic Flux Density ◽  
Small Scale ◽  
Flux Emergence ◽  
Vector Information

Aims. Two types of flux emergence were recently discovered in numerical simulations: magnetic loops and magnetic sheet emergence. While magnetic loop emergence has been documented well in recent years using high-resolution full Stokes data from ground-based telescopes as well as satellites, magnetic sheet emergence is still an understudied process. We report here on the first clear observational evidence of a magnetic sheet emergence and characterise its development. Methods. Full Stokes spectra from the Hinode spectropolarimeter were inverted with the Stokes Inversion based on Response functions (SIR) code to obtain solar atmospheric parameters such as temperature, line-of-sight velocities, and full magnetic field vector information. Results. We analyse a magnetic flux emergence event observed in the quiet-Sun internetwork. After a large-scale appearance of linear polarisation, a magnetic sheet with horizontal magnetic flux density of up to 194 Mx cm−2 hovers in the low photosphere spanning a region of 2–3 arcsec. The magnetic field azimuth obtained through Stokes inversions clearly shows an organised structure of transversal magnetic flux density emerging. The granule below the magnetic flux sheet tears the structure apart leaving the emerged flux to form several magnetic loops at the edges of the granule. Conclusions. A large amount of flux with strong horizontal magnetic fields surfaces through the interplay of buried magnetic flux and convective motions. The magnetic flux emerges within 10 minutes and we find a longitudinal magnetic flux at the foot points of the order of ∼1018 Mx. This is one to two orders of magnitude larger than what has been reported for small-scale magnetic loops. The convective flows feed the newly emerged flux into the pre-existing magnetic population on a granular scale.

Nature-Inspired Microfluidic Manipulation Using Magnetic Actuators

2007 ◽  
Vol 1052 ◽  
Author(s):  
S. N. Khaderi ◽  
D. Ioan ◽  
J. M. J. den Toonder ◽  
P. R. Onck
Keyword(s):  
Magnetic Field ◽  
Reynolds Number ◽  
External Magnetic Field ◽  
Polymer Films ◽  
Magnetic Particles ◽  
Fluid Flows ◽  
Magnetic Actuators ◽  
Magnetically Actuated ◽  
Micro Channels ◽  
Micro Actuators

AbstractMagnetically actuated micro-actuators are proposed to propel and manipulate fluid in micro-channels. As the fluid flows at low Reynolds number in such systems, the actuator should move in an asymmetric manner. The proposed actuators are polymer films with embedded magnetic particles, which are actuated by an external magnetic field. Based on the nature of the particles, the films can be either ferromagnetic or super-paramagnetic. We have identified four configurations in which the actuator exhibits an asymmetric motion.

Research on Distribution of Magnetic Particles Based on Magnetic Field Control Grinding Wheel

2013 ◽  
Vol 797 ◽  
pp. 428-431
Author(s):  
Shao Hui Yin ◽  
Sheng Gong ◽  
Feng Jun Chen ◽  
Ming Wang
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Magnetic Flux ◽  
Magnetic Particles ◽  
Magnetic Particle ◽  
Particle Distribution ◽  
Magnetic Flux Density ◽  
Grinding Wheel ◽  
Field Control ◽  
Orderly Arrangement

In order to solve the problem of the randomly arrangement of the diamond abrasives, a novel orderly arrangement grinding wheel was developed, which used magnetic field to control the magnetic particles to drive diamond abrasives orderly arrangement. Effects of magnetic flux density on magnetic particle distribution was studied. And effects of magnetic particle proportion on magnetic particle distribution was studied. Grinding experiments were carried out on the tungsten carbide YG8 and surface roughness after grinding was also analyzed.

Behavior of Magnetorheological Fluids Employing Carrier Fluids Certified for Landing Gear Use

2008 ◽  
Author(s):  
Louise Ahure´ ◽  
Norman M. Wereley
Keyword(s):  
Magnetic Field ◽  
Magnetic Particles ◽  
Landing Gear ◽  
Small Scale ◽  
Hydraulic Systems ◽  
Sedimentation Analysis ◽  
Mr Fluids ◽  
Helicopter Landing ◽  
Different Characteristics ◽  
Potential Use

Magnetorheological (MR) fluids were prepared in order to investigate their performance for potential use in landing gear hydraulic systems, such as shock struts. MR fluids formulated here utilized three hydraulic oils certified for use in landing gear, two different average diameters of spherical magnetic particles, and a Lecithin surfactant. The fluids were characterized in order to measure and analyze their rheological behavior. Therefore, different characteristics were taken into consideration, such as 1) magnetorheology as a function of magnetic field, 2) cycling of a small-scale damper undergoing sinusoidal excitations at frequencies of 2.5 and 5 Hz, and 3) sedimentation analysis conducted with an inductance-based sensor. The goal of this research is to analyze the performance of these particular MR fluids, to compare their behavior to standard commercial MR fluids, and to determine their feasibility for use in helicopter landing gear.

Additive Manufacturing of Magnetically Loaded Polymer Composites: An Experimental Study for Process Development

2017 ◽  
Author(s):  
Balakrishnan Nagarajan ◽  
Alejandro F. Eufracio Aguilera ◽  
Ahmed Qureshi ◽  
Pierre Mertiny
Keyword(s):  
Magnetic Field ◽  
Additive Manufacturing ◽  
Polymer Composites ◽  
Magnetic Particles ◽  
Magnetic Flux Density ◽  
Droplet Deformation ◽  
Particle Settling ◽  
Droplet Stability ◽  
Particle Alignment ◽  
The Magnetic Field

Material jetting is an additive manufacturing technique that allows to produce three-dimensional solid parts without tooling and with minimum material wastage. In this context, magnetically loaded polymer composites with oriented magnetic particles are promising for many electrical and electronic applications. In this study, permanent magnet based alignment configurations were evaluated and compared in terms of different magnetic flux density using the finite element method. The particle alignment in cured droplet specimens and the stability of magnetically loaded polymer droplets deposited on a substrate were characterized for a material jetting based additive manufacturing process. Particle alignment and droplet deformation under the influence of the magnetic field was captured using real-time optical microscopy. The influence of rheological additives in controlling droplet stability in the magnetic field and mitigating particle settling were studied through experiments. The primary goal of this research was to identify parameters that facilitate high particle alignment, and material combinations that enhance droplet stability and mitigate particle settling. This fundamental research serves to enhance the understanding of processes and material behaviour for material jetting based additive manufacturing.

Study on an Ultra-Precision Plane Magnetic Abrasive Finishing Process by Use of Alternating Magnetic Field

2013 ◽  
Vol 395-396 ◽  
pp. 985-989 ◽  
Author(s):  
Jin Zhong Wu ◽  
Yan Hua Zou
Keyword(s):  
Magnetic Field ◽  
Magnetic Particles ◽  
Water Soluble ◽  
Alternating Magnetic Field ◽  
Magnetic Flux Density ◽  
Magnetic Abrasive Finishing ◽  
Finishing Process ◽  
Abrasive Finishing ◽  
Ultra Precision ◽  
Surface Precision

In this paper, a new plane magnetic abrasive finishing process by using alternating magnetic field is proposed to improve the efficiency and surface precision. In alternating magnetic field, the forced direction of magnetic particles is changing. Therefore, magnetic particles could produce the up and down movement, which promote the scatter of magnetic particles , improve the roll of abrasive particles and enhance the utilization of abrasive. In order to know well the magnetic intensity distribution in processing area, measured the magnetic flux density. Finishing force is important to understand the mechanism of material removal, investigated to the finishing force and contrasted to the movement changes of magnetic particles in water-soluble finishing fluid and oily finishing fluid. A set of experimental devices have been designed to realize surface polishing on C2801 brass plate, the results proved the feasibility of this method, which can improve the workpiece surface quality.

The Orientation Study of Ba-Sr Hexaferrite Particles by Parallel Magnetic Field Press

2015 ◽  
Vol 827 ◽  
pp. 223-228
Author(s):  
Agus Sukarto Wismogroho ◽  
Wahyu Bambang Widayatno ◽  
Toto Sudiro ◽  
Didik Aryanto
Keyword(s):  
Magnetic Field ◽  
Magnetic Particles ◽  
Crystal Structure Analysis ◽  
Magnetic Field Induction ◽  
Magnetic Flux Density ◽  
Field Induction ◽  
Orientation Process ◽  
Magnetic Remanence ◽  
Axis Parallel ◽  
The Given

It is well known that an orientation treatment on magnetic particles may increase magnetic flux density than that of those without treatment. In this work, the study on orientation of Barium Stronsium Hexaferrite (Ba-Sr Hexaferrite) particles using parallel system of magnetic field press was conducted to investigate the effect of powder orientation on its characteristic. Samples were compacted while the varied magnetic field induction were given, molded and then sintered at 1200°C for 1 hour. The measurement of magnetic properties showed that orientation process increased the value of magnetic remanence up to 173% (1264 Gauss). The magnetic field induction of 0.4 T was found to be the optimum value, where further increase of magnetic field did not give significant change. The crystal structure analysis showed the increase of peak of <001> plane which is correlated with the c-axis of Ba-Sr Hexaferrite crystal. In addition, the peak which is correlated with the opposite direction of c-axis disappeared, while the peaks between those directions decreased significantly. The micrograph of Ba-Sr Hexaferrite particles showed the alignment of c-axis parallel to the given magnetic field induction. These results showed the phenomenon of mechanical particle revolving and particle arrangement during the orientation process by which determined the obtained magnetic remanence.

Analysis of magneto rheological elastomers for energy harvesting systems

2020 ◽  
Vol 64 (1-4) ◽  
pp. 439-446
Author(s):  
Gildas Diguet ◽  
Gael Sebald ◽  
Masami Nakano ◽  
Mickaël Lallart ◽  
Jean-Yves Cavaillé
Keyword(s):  
Magnetic Field ◽  
Energy Harvesting ◽  
Shear Strain ◽  
Magnetic Induction ◽  
Magnetic Particles ◽  
Homogeneous Magnetic Field ◽  
Electrical Signal ◽  
Harvesting Systems ◽  
Dc Bias ◽  
Magneto Rheological

Magneto Rheological Elastomers (MREs) are composite materials based on an elastomer filled by magnetic particles. Anisotropic MRE can be easily manufactured by curing the material under homogeneous magnetic field which creates column of particles. The magnetic and elastic properties are actually coupled making these MREs suitable for energy conversion. From these remarkable properties, an energy harvesting device is considered through the application of a DC bias magnetic induction on two MREs as a metal piece is applying an AC shear strain on them. Such strain therefore changes the permeabilities of the elastomers, hence generating an AC magnetic induction which can be converted into AC electrical signal with the help of a coil. The device is simulated with a Finite Element Method software to examine the effect of the MRE parameters, the DC bias magnetic induction and applied shear strain (amplitude and frequency) on the resulting electrical signal.

scholarly journals Design of a New 1D Halbach Magnet Array with Good Sinusoidal Magnetic Field by Analyzing the Curved Surface

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2522
Author(s):  
Guangdou Liu ◽  
Shiqin Hou ◽  
Xingping Xu ◽  
Wensheng Xiao
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Permanent Magnets ◽  
Air Gap ◽  
Curved Surface ◽  
Magnetic Flux Density ◽  
Sinusoidal Magnetic Field ◽  
The Magnetic Field

In the linear and planar motors, the 1D Halbach magnet array is extensively used. The sinusoidal property of the magnetic field deteriorates by analyzing the magnetic field at a small air gap. Therefore, a new 1D Halbach magnet array is proposed, in which the permanent magnet with a curved surface is applied. Based on the superposition of principle and Fourier series, the magnetic flux density distribution is derived. The optimized curved surface is obtained and fitted by a polynomial. The sinusoidal magnetic field is verified by comparing it with the magnetic flux density of the finite element model. Through the analysis of different dimensions of the permanent magnet array, the optimization result has good applicability. The force ripple can be significantly reduced by the new magnet array. The effect on the mass and air gap is investigated compared with a conventional magnet array with rectangular permanent magnets. In conclusion, the new magnet array design has the scalability to be extended to various sizes of motor and is especially suitable for small air gap applications.

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