Guiding the Nonmagnetic Particles by Magnetic Nanoparticles in a Microfluidic Device Using External Magnetic Fields

2009 ◽  
Author(s):  
R. Asmatulu ◽  
B. Zhang ◽  
N. Nuraje
Keyword(s):  
Magnetic Nanoparticles ◽  
Microfluidic Device ◽  
Magnetic Force ◽  
Power Level ◽  
Field Testing ◽  
Microfluidic System ◽  
Efficient Separation ◽  
Micro Channels ◽  
Nonmagnetic Particles ◽  
The Magnetic Field

A microfluidic device was fabricated via UV lithography technique to separate nonmagnetic fluoresbrite carboxy microspheres (∼4.5 μm) from the ferrofluids made of magnetic nanoparticles (∼10 nm). A mixture of microspheres and ferrofluid was injected to lithographically developed Y shape micro channels, and then by applying the external magnet field, the fluoresbrite carboxy microspheres and ferrofluids were clearly separated into different channels because of the magnetic force acting on those nonmagnetic particles. During the fabrication, a number of different parameters, such as UV exposure times, UV power level and photoresist thickness were tested to optimize for our needs. In addition, in the magnetic field testing, different pumping speeds, and particle concentrations associated with the various distances between the magnet and the microfluidic system were studied for an efficient separation.

scholarly journals Magnetoactive acoustic metamaterials based on nanoparticle-enhanced diaphragm

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xingwei Tang ◽  
Shanjun Liang ◽  
Yusheng Jiang ◽  
Cong Gao ◽  
Yujin Huang ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Effective Mass ◽  
Magnetic Force ◽  
Mass Density ◽  
Second Derivative ◽  
Acoustic Metamaterials ◽  
Vibration Properties ◽  
Potential Applications ◽  
Membrane Type ◽  
The Magnetic Field

AbstractMagnetoactive membrane-type acoustic metamaterials are fabricated by coating a layer of magnetic nanoparticles on the polyethylene (PE) membranes and their vibration characters are investigated experimentally. From our experiments, we discovered that, under different magnetic fields by varying the distance between a magnet and the membranes, such membranes exhibit tunable vibration eigenfrequencies (the shift towards lower frequencies), which is caused by the variation of the effective mass density and effective tension coefficient resulted from the second derivative of the magnetic field. The strong magnetic force between the layer of magnetic nanoparticles and the magnet enhances the eigenfrequency shift. A spring oscillator model is proposed and it agrees well with the experimental results. We also experimentally observed that the vibration radius, effective mass density, and effective tension coefficient of the membranes can enormously affect the eigenfrequencies of the membranes. We believe that this type of metamaterials may open up some potential applications for acoustic devices with turntable vibration properties.

Study of MFM Application in Semiconductor Failure Analysis

2004 ◽  
Author(s):  
Way-Jam Chen ◽  
Lily Shiau ◽  
Ming-Ching Huang ◽  
Chia-Hsing Chao
Keyword(s):  
Magnetic Field ◽  
Failure Analysis ◽  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Current Flow ◽  
Force Microscopy ◽  
The Magnetic Field ◽  
A Current

Abstract In this study we have investigated the magnetic field associated with a current flowing in a circuit using Magnetic Force Microscopy (MFM). The technique is able to identify the magnetic field associated with a current flow and has potential for failure analysis.

scholarly journals Design and Manufacturing of a Disposable, Cyclo-Olefin Copolymer, Microfluidic Device for a Biosensor †

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1178 ◽  
Author(s):  
Jorge Prada ◽  
Christina Cordes ◽  
Carsten Harms ◽  
Walter Lang
Keyword(s):  
Microfluidic Device ◽  
Heating Temperature ◽  
Low Cost ◽  
Reaction Chamber ◽  
Microfluidic System ◽  
Heating Process ◽  
Design And Manufacturing ◽  
On Chip ◽  
Working Parameters ◽  
Auto Fluorescence

This contribution outlines the design and manufacturing of a microfluidic device implemented as a biosensor for retrieval and detection of bacteria RNA. The device is fully made of Cyclo-Olefin Copolymer (COC), which features low auto-fluorescence, biocompatibility and manufacturability by hot-embossing. The RNA retrieval was carried on after bacteria heat-lysis by an on-chip micro-heater, whose function was characterized at different working parameters. Carbon resistive temperature sensors were tested, characterized and printed on the biochip sealing film to monitor the heating process. Off-chip and on-chip processed RNA were hybridized with capture probes on the reaction chamber surface and identification was achieved by detection of fluorescence tags. The application of the mentioned techniques and materials proved to allow the development of low-cost, disposable albeit multi-functional microfluidic system, performing heating, temperature sensing and chemical reaction processes in the same device. By proving its effectiveness, this device contributes a reference to show the integration potential of fully thermoplastic devices in biosensor systems.

Improving Turret Control on Military Vehicles

2009 ◽  
Author(s):  
Thomas W. Anderson ◽  
Nathaniel A. Clark ◽  
Wesley E. Kotz ◽  
Briana D. Stremick ◽  
O¨zer Arnas ◽  
...  
Keyword(s):  
Hall Effect ◽  
Output Voltage ◽  
Magnetic Force ◽  
Electric Signal ◽  
Similar Response ◽  
Hall Effect Sensor ◽  
Military Vehicles ◽  
Tactical Vehicle ◽  
The Magnetic Field ◽  
Mechanical Assistance

Recent additions of armor have made light tactical vehicle turrets heavy enough that mechanical assistance is required for them to rotate. The Army’s solution is the Battery Powered Motorized Traversing Unit (BPMTU) which uses a joystick to traverse the turret. Use of the joystick distracts the gunner and prevents the gunner from continuously engaging the target while rotating the turret. This paper presents a modification to the weapon mount that allows the turret to be controlled by the position of the weapon itself and emphasizes the design process used to develop the inovation. With this design, the gunner can now maintain contact with a target, while rotating the turret, without fiddling with the joystick. The Weapon Activated and Controlled Turret (WACT) consists of two primary components; the bottom component is stationary relative to the turret and contains a Hall effect sensor and the top component rotates with the weapon and holds a linear magnet. As the position of the sensor relative to the magnet changes, the corresponding strength of the magnetic field also varies. This change in magnetic force induces a similar response in the output voltage of the Hall effect sensor, effectively translating rotational motion into an electric signal able to control the turret motor.

In Vitro Evaluation of Capturing and Dissolving the Clot by Magnetic Nanoparticles Carrying a Thrombolytic Agents Instead of Temporary Inferior Vena Cava (IVC) Filter

2020 ◽  
Vol 16 (11) ◽  
pp. 1623-1632
Author(s):  
Abbas Moghanizadeh ◽  
Fakhreddin Ashrafizadeh ◽  
Jaleh Varshousaz ◽  
Mahshid Kharaziha
Keyword(s):  
Magnetic Field ◽  
Magnetic Nanoparticles ◽  
Vena Cava ◽  
Simple Method ◽  
Thrombolytic Agents ◽  
Blood Clots ◽  
Life Threatening ◽  
The Magnetic Field ◽  
Different Levels

This study aims to evaluate the efficiency of a novel in vitro technique in clot capturing and dissolving them by applying magnetic force on magnetic nanoparticles (MNP) carrying thrombolytic agents. It is a quick and simple method to protect patients from a life-threatening pulmonary embolism in an emergency to provide time for the medical team. To analyze the in vitro efficiency of nano-magnetic capturing and dissolving of clots (NCDC), different levels of process parameter including strength magnetic field (0.1, 0.2 and 0.3 T) and fluid flow rate (2.5, 5 and 7 l/min) are exposed to different blood clots sizes from 5 × 10 to 20 × 10 mm2 (length × diameter), in an in vitro flow model. The results show that by increasing the parameters to their maximum values, it is possible to immobilize 100% of the clots and dissolve around 61.4% of clots weight. In addition, the clot-dissolving is directly proportional to the magnetic field strength. NCDC is an efficient technique in immobilizing and dissolving the clots and its efficiency depends on process parameters especially the magnetic field.

scholarly journals Remote manipulation of magnetic nanoparticles using magnetic field gradient to promote cancer cell death

2018 ◽  
Author(s):  
Mahendran Subramanian ◽  
Arkadiusz Miaskowski ◽  
Stuart Iain Jenkins ◽  
Jenson Lim ◽  
Jon Dobson
Keyword(s):  
Magnetic Field ◽  
Magnetic Nanoparticles ◽  
Field Gradient ◽  
Biomedical Applications ◽  
Magnetic Field Gradient ◽  
Field Source ◽  
Remote Manipulation ◽  
Cancer Cell Death ◽  
The Magnetic Field

AbstractThe manipulation of magnetic nanoparticles (MNPs) using an external magnetic field, has been demonstrated to be useful in various biomedical applications. Some techniques have evolved utilizing this non-invasive external stimulus but the scientific community widely adopts few, and there is an excellent potential for more novel methods. The primary focus of this study is on understanding the manipulation of MNPs by a time-varying static magnetic field and how this can be used, at different frequencies and displacement, to manipulate cellular function. Here we explore, using numerical modeling, the physical mechanism which underlies this kind of manipulation, and we discuss potential improvements which would enhance such manipulation with its use in biomedical applications, i.e., increasing the MNP response by improving the field parameters. From our observations and other related studies, we infer that such manipulation depends mostly on the magnetic field gradient, the magnetic susceptibility and size of the MNPs, the magnet array oscillating frequency, the viscosity of the medium surrounding MNPs, and the distance between the magnetic field source and the MNPs. Additionally, we demonstrate cytotoxicity in neuroblastoma (SH-SY5Y) and hepatocellular carcinoma (HepG2) cells in vitro. This was induced by incubation with MNPs, followed by exposure to a magnetic field gradient, physically oscillating at various frequencies and displacement amplitudes. Even though this technique reliably produces MNP endocytosis and/or cytotoxicity, a better biophysical understanding is required to develop the mechanism used for this precision manipulation of MNPs, in vitro.

scholarly journals Application of Magnetic Nanoparticles with Structure of Core-shell, as Bactericidal

2018 ◽  
Vol 2 (1) ◽  
pp. 01-04
Author(s):  
Mansour Binandeh
Keyword(s):  
Magnetic Nanoparticles ◽  
Pathogenic Bacteria ◽  
Antibacterial Properties ◽  
Correlation Method ◽  
Core Shell ◽  
Ft Ir ◽  
Chemical Correlation ◽  
Ir Analysis ◽  
The Magnetic Field

Initially, magnetic nanoparticles (MNP) Fe3O4 are synthesized by a chemical correlation method and its core / shell structure is detected using SEM, FT-IR analysis. The purpose of this production was to use the nanoparticle performance level in the absorption of antibiotics, namely, ampicillin (amp). Absorption sampling was analyzed by UV-Vis spectrophotometer and the results indicate that the absorbance of the ampere increases to 85%. The bond between these two is electrostatic bonding, which was confirmed by EDX analysis. Ultimately, this compound was used for the antibacterial process. In this case, the MNP-amp compound was added in a natural amount of 20 μl a bacterial culture pattern overnight (In-vitro). The results showed that 95% of the bacteria were killed (confirmation of antibacterial properties of MNP). Therefore, it can be transmitted intentionally by controlling the magnetic field into living cells for the destruction of pathogenic bacteria.

Sign in / Sign up

Export Citation Format

Share Document