Magnetoelastic Sensor Research Articles

Modelling the Characteristics of Ring-Shaped Magnetoelastic Force Sensor in Mohri's Configuration.

Magnetoelastic force sensors exhibit high sensitivity and robustness. One commonly used configuration of force sensor with a ring-shaped core was presented by Mohri at al. In this configuration force is applied in the direction of a diameter of the core. However, due to inhomogeneous distribution of stresses, model of such sensor has not been presented yet. This paper is filling the gap presenting a new method of modelling the magnetoelastic effect, which is especially suitable for the finite element method. The presented implementation of proposed model is in good agreement with experimental data and creates new possibilities of modelling other devices utilizing magnetoelastic effect.

Mathematical models and algorithms of optimal load management of electrical consumers

The article investigated the static, dynamic and metrological characteristics of new magnetoelastic force sensors taking into account the distribution of Load profile smoothing based on optimal power management is considered to be one of the main ways to ensure efficient operation of energy systems in the short-term planning. Smoothing load profile with a view to reducing costs can be implemented on the ways in which consumers could be affected by administrative and economic measures. Administrative measures are associated with the forced restriction of consumer loads in certain intervals of the planning period. On the one hand, these measures provide benefits to the power system by smoothing load profile, and on the other hand, they cause damage to consumers. Ultimately, in some cases, the damage may be greater than the benefits as a whole to the power system. Therefore, it is advisable to use them in conditions of shortage of power and electricity in the power system. Optimal planning of short-term regimes of power systems according to received, after alignment, rigid load profile can be carried out by traditional methods. The solution of such a problem can be initially carried out under conditions of non-rigid load profile resulting from the directive use of administrative and economic measures carried out with the help of specially developed models. In this regard, the paper proposes a mathematical model of the problem of optimizing load profile of regulated electrical consumers with optimal planning of short-term power system modes, an algorithm for optimal planning of a short-term power system mode with optimizing load profile of regulated power consumers. And also, algorithms are proposed for accounting for simple and functional constraints in the form of equalities and inequalities when optimizing load profile. The effectiveness of the described algorithm for optimizing the short-term mode of the power system, taking into account the optimal load control of adjustable electric locomotives, has been studied using the example of optimal coverage of the load profile of power system, which contains two consumers with adjustable load profile, and two TPPs. Based on the calculated experimental studies computational qualities, it was determined that the proposed mathematical model of the problem is adequate, the developed algorithms for optimal planning of short-term power system modes with optimization of load profile of regulated electric consumers and taking into account various types of limitations have high computational qualities.

Rhombic-magnetoelastic/metal–organic framework functionalized resonators for highly sensitive toluene detection

Rhombic magnetoelastic sensors functionalized with MOFs have been applied for the wireless sensing of VOCs showing very promising results.

Stress Dependence of the Small Angle Magnetization Rotation Signal in Commercial Amorphous Ribbons.

The results of the investigation on tensile stress dependence of the SAMR (small angle magnetization rotation) signal in soft magnetic amorphous ribbons are presented. Exemplary results for commercially available, negatively magnetostrictive 2705M, 2714A, and 6030D amorphous ribbons show significant stress dependence, in contrast to positively magnetostrictive 2826MB alloy. The magnetoelastic hysteresis of the obtained characteristics is compared, as well as the influence of the biasing H field and supply current variations. Based on the results, 2705M alloy with near-zero negative magnetostriction is proposed as best suited for a SAMR-based, magnetoelastic force sensor.

Correlating the mass and mechanical property changes during the degradation of PEG-based adhesive.

Change in mechanical property of a degrading adhesive is critical to its performance. However, characterization of degradation behavior is often limited to tracking its mass loss. 4-armed PEG end modified with dopamine (PEG-DA) was used as a model bioadhesive to correlate its change in mass with change in mechanical property. Shear modulus (G) was calculated based on the mass and average molecular weight between crosslinks of PEG-DA, while the storage modulus (G') was determined by oscillatory rheometry. G decreased slowly within the first week of degradation (10% reduction by week 2), while G' decreased by 60% during the same period. This large discrepancy is due to the partially disconnected and elastically ineffective PEG polymer, which is trapped within the adhesive network. This resulted in minimal mass change and higher calculated G value during the earlier time points. Therefore, tracking mass loss profile alone is inadequate to completely describe the degradation behavior of an adhesive. Additionally, PEG-DA was coated onto magnetoelastic (ME) sensors, and the change in the resonance amplitude of the sensor corresponded well with dry mass loss of PEG-DA. ME sensing provide a non-destructive method to track the mass loss of the coated adhesive.

Improved Magnetoelastic (ME) Sensing By Using Gelatin for Salmonella Pick-up from Large Scale Surfaces

ME sensing, as a fast, on-site, and label-free measurement technique, has been studied in the recent decade for the detection of Salmonella. During the development of ME sensors, there has been a dilemma – to increase sensitivity, the size of a ME sensor must be reduced, while in direct surface detection, a reduced sensor size results in a smaller detection area, larger edge effect, and is harder to handle. To solve this problem, in this paper we introduce a novel gelatin assisted ME sensing system. A gelatin solution at a concentration of 0.05 g/ml was prepared and uniformly applied to the sample surface. A thin gelatin film formed after 2 hours of drying and was easily peeled off to remove most of the Salmonella colonies from the surface. With the application of gelatin, the detection area of one ME sensor was improved from 0.2 mm x 1 mm to 30 mm x 30 mm. In our previous study, swabbing, as an inexpensive, easy-to-use, and widely accepted sampling method, has been used to improve the ME biosensing system for quick detection of surface pathogens. Compared with the swab sampling method, not only was the recovery rate of gelatin assisted ME sensing system much higher, but the detection limit can be significantly improved.

The Influences of Organic Matter Concentrations in Juices for Pathogen Detection Using Phage-Based Biosensors

Fruit and vegetables are playing an important role of today’s healthy diet. Juices are the liquid extracts from fruit and vegetables, which contain lots of organic matters, such as vitamins, minerals and plant chemicals (phytonutrients). Commercial bottle juices usually contain different percentages of real juices in their juice products. Therefore, the amount of organic matter content in juices are different in various brands of juices. The foodborne pathogen outbreaks through the consumption of fruit or vegetable juices continue to be reported (CDC, 2016). It indicates that pathogens like Salmonella can be packaged with juices even with current manufacture microbial-inactivation process. According to several studies, the acidity in tomatoes juice and the phyto-chemicals (like chlorophyll) from damage leaves in leafy greens samples can affect the sensitivity of pathogen detection in juices. For example, chlorophyll is one of the substances in leafy green juice that inhibits PCR reaction for pathogen detection. This made the pathogen detection in some juices a difficult task to achieve. The phage magnetoelastic (ME) biosensors are wireless sensors, whose resonance oscillation and resonance frequency are actuated and detected through magnetic fields. These biosensors have been shown to be highly sensitive and specific in pathogen detection including Salmonella on various food surfaces or liquids (Li et al., 2010). Therefore, in this study, different concentrations of juices from tomatoes and spinach with artificially spiked Salmonella (at the concentration of 104 cfu/ml) was tested by ME biosensors. The influence of pathogen detection capability was then studied by comparing the bacterial capture rates on biosensors. In tomato juice, the results showed that the capture rate of Salmonella can be reached up to 90.68% by using 100 ME biosensors in a tube rocking experiment with 10% tomato juice content. In spinach juice, the capture rate of Salmonella showed similar results as 90.68% in the same 10% juice concentration. However, when the juice concentration of spinach went up to 15% and 20%, the bacterial capture rate slightly decreased. The Salmonella capture rate were shown as 89.82% and 89.065, respectively. The decreasing of capture rate was obvious by using 50 ME sensors for the 15% and 20% spinach juices. In conclusion, by using 100 phage ME biosensors, the detection platform can detect as high as 89% Salmonella in high juice concentration (15 % and 20%) of both tomato and spinach juice samples. While in the moderate juice concentration zone (5-10%), the ME biosensors show very promising results of detecting 90% Salmonella in both juices.

Formation and Detection of Magnetic CoNiFe Nanowire Network Using Magnetoelastic Sensor

In this study, CoNiFe magnetic nanowires were detected using a magnetoelastic sensor (ME) without any coating. Amorphous ferromagnetic ribbon of Metglass 2826 (Fe40Ni38Mo4B18) was used as a magnetoelastic sensor. The magnetoelastic ribbons were drop coated with Co12Ni64Fe24 magnetic nanowires in order to study how the mass deposition affects the resonance frequency and to determine the amount of coated nanowire. It was found that the minimum amount of detected nanowire can be as low as 200 ng. It was also shown that the nanowire network was developed on the surface of Metglass 2826 MB magnetoelastic sensor.

A pattern matching identification method of cracks on cantilever beams through their bending modes measured by magnetoelastic sensors

This work introduces a simple method on identification of single transverse cracks on cantilever beams, having as an input the first 8 bending modes of the beam. The beam modeling part of the method was developed based on a finite element analysis and fracture mechanics theory, and implemented using Matlab programming. Bending mode normalized frequencies were extracted from the model, versus crack location (CL) and crack depth (CD), and all possible normalized frequency ratios (NFRs) were calculated in order to be stored in a database. This database information was used to find the optimum CL and CD values from input data, through a pattern matching process. Two different approaches were presented to validate the method, one experimental and one numerical. In the case of the experimental approach a number of 19 beam specimens of aluminum alloy 6063 were used, with various fixed crack locations and depths, and the extracted CL and CD errors were 1.7% and 11.4%, respectively. The measurement of the 8 bending modes was accomplished non-invasively by the use of magnetoelastic vibration sensors, which were composed of 29 μm thin ribbons of magnetoelastic material Metglas 2826MB3. On the other hand, the numerical approach was performed using ANSYS 2016 Workbench software on beam designs with the same physical and geometrical characteristics as the beam specimens used in the experiment. The extracted CL and CD errors are found to be 0.7% and 8.5%, respectively. The above errors show that the proposed method is extremely capable of predicting the crack location and quite capable of predicting the crack depth. This work sets the basic prospects for the design of a new Structural Health Monitoring (SHM) technique combining the efficiency of the magnetoelastic sensors together with the proposed method.

A Portable Device for Rapid Detection of Human Serum Albumin using an immunoglobulin-coating-based Magnetoelastic Biosensor

Abnormal protein concentration levels in human body fluids, such as urine, serum etc., are considered to associate with disease states, providing essential information for the pre-clinical diagnosis. This paper presents a wireless immunoglobulin-coated magnetoelastic (ME) biosensor for fast, cost-effective detections of human serum albumin (HSA) with small sample volumes at a microliter scale. This is the first portable resonant sensor based on magnetostrictive effect that can monitor different molecular states of HSA. Anti-HSA Immunoglobulin G (IgG) was immobilized on the surface of the ME sensor to selectively capture HSA. The rapid conjugation between the antibody and antigen changed the sensor surface states and thus induced resonance frequency shifts (RFS), which were monitored in real time for the qualitative and quantitative analysis of HSA. This paper brings forward a System on Chip (SoC)-based system architecture to realize the function of RFS sampling. The performance of the portable device was validated to be comparable to that of the Vector Network Analyzer (VNA) AV3620 using different concentrations of HSA solution. The RFS were linearly proportional to the HSA concentrations in the range from 0.1 to 100 μg/mL with a linearity up to 0.998, a sensitivity of 8.70 Hz/μg.mL-1 and a detection limit of 0.039 μg/mL, indicating good feasibility of this method. Meanwhile, the response of this portable ME biosensor was quick and specific to HSA targets. This ME biosensor shows high potential to be used in diagnosing abnormal HSA.

Enhanced mass sensitivity in novel magnetoelastic resonators geometries for advanced detection systems

Acoustic wave based sensors have a major impact in the detection of low concentration of biological and chemical agents. Magnetoelastic resonator platforms are particularly interesting due to their low cost and wireless detection process. However, efforts in improving their performance are still focused only in the reduction of the size. In the present study, a new way to increase the sensitivity of magnetoelastic sensor platforms is proposed. This work demonstrates, both theoretically and experimentally, that the mass load sensitivity can be improved by tailoring sensor geometry and mass load position. Triangular and arched triangular shapes have been tested and compared with the traditional rectangular ones. It has been observed an increase in the mass sensitivity of more than 400% in Metglas® 2826MB magnetoelastic sensor by using new sensor platform geometries. Even higher sensitivities have been obtained by doing partial coatings on the sensor edge/tip instead of the traditional complete uniform coating. New geometries present an increase up to 6400% in partial coatings. The obtained results clearly show the key role of magnetoelastic resonator platforms geometries in the increase of mass load sensitivity and their importance in the draw of future labor-free and wireless sensors for low mass detection systems.

Mathematical models of magnetic circuits of sensors of functional diagnostic systems of electric carriers

The article discusses the magnetic circuit of the developed magnetoelastic sensors of mechanical forces used in the systems of functional diagnostics of electric locomotives is investigated, taking into account the distribution of the magnetic resistance of coaxially arranged ring cores, the magnetic capacitance of the ring gap between them, the section of magnetizing and measuring windings. It is shown that the magnetic voltage along the sensor magnetic circuit is nonlinearly distributed and changes its sign at the magnetic neutral point, and the magnetic flux is non-constant and has a minimum value at the magnetic neutral point, and with an increase in the magnetic flux attenuation coefficient in the magnetic conductor magnetic flux along the length of the magnetic circuit increases.

Applications and Advances of Magnetoelastic Sensors in Biomedical Engineering: A Review.

We present a comprehensive investigation into magnetoelastic sensors (MES) technology applied to biomedical engineering. This includes the working principles, detection methods, and application fields of MES technology. MES are made of amorphous metallic glass ribbons and are wireless and passive, meaning that it is convenient to monitor or measure the parameters related to biomedical engineering. MES are based on the inverse magnetoelastic (Villari) effect. When MES are subjected to mechanical stress, their magnetic susceptibility will change accordingly. And the susceptibility of MES is directly related to their magnetic permeability. The varying permeability can positively reflect the applied stress. The various detection methods that have been developed for different field applications include measurement of force, stress, and strain, monitoring of various chemical indexes, and consideration of different biomedical parameters such as the degradation rate and force conditions of artificial bone, as well as various physiological indexes including ammonia level, glucose concentration, bacteria growth, and blood coagulation.

High sensitivity detection of human serum albumin using a novel magnetoelastic immunosensor

In this paper, a novel and wireless magnetoelastic (ME) immunosensor for human serum albumin (HSA) detection is presented. Gold nanoparticles layer on the sensor surface can enhance its biocompatibility, stability and sensitivity. The anti-HSA IgG, as a capture probe, was immobilized on the gold-plated ME sensor surface to specifically recognize the target HSA. The binding complex accumulated on the immunosensor surface leads to a decrease in the immunosensor’s resonance frequency, corresponding to the HSA concentrations. The atomic force microscopy, the Raman spectrum and the X-ray electron spectroscopy were used to confirm that the antibody immobilization was successful. Furthermore, to enhance its sensitivity, the working concentration of the antibody was optimized to be 25 µg ml−1. The experimental results demonstrated that the immunosensor exhibited a linear response to the logarithm of HSA concentrations ranging from 0.01 to 100 µg ml−1, with the sensitivity of 9.3 Hz/μg ml−1 and the detection limit of 0.01 µg ml−1, which is significantly lower than the minimum diagnosis limit of urine microalbumin.

A Modified Impedance-Frequency Converter for Inexpensive Inductive and Resistive Sensor Applications.

In this paper an exceptionally simple transducer is presented that is developed for experimental and custom-made sensors with inductive or resistive impedance output. It is based on a venerable 555 Integrated Circuit in a modified astable configuration. Due to single supply 5 V operation, it is directly compatible with most modern microcontroller systems, such as the popular Arduino platform. Various exemplary sensor characteristics are presented, including displacement, force, magnetic field, temperature and light sensing applications. While the transducer is not designed for high accuracy, it allows for fast and inexpensive application of various experimental sensors, such as magnetoelastic or GMI (Giant Magneto Impedance) sensors.

Research of the basic characteristics of the new magnetic elastic force sensors

The article investigated the static, dynamic and metrological characteristics of new magnetoelastic force sensors taking into account the distribution of parameters of electrical and magnetic circuits. It is shown that taking into account the distribution of circuit parameters during calculations significantly reduces the error in calculating the characteristics of magnetoelastic sensors.

Investigation of the properties correlation of physical and mechanical characteristics of ferromagnets based on magnetoelastic sensors of mechanical stresses

The determination of the stress condition is a topical issue. At present, various non-destructive examination methods, such as strain gauge, magnetic, ultrasonic methods, and others are used to analyze pipelines stress condition. Each of them has its advantages and disadvantages. There is often the need to use several experimental non-destructive methods simultaneously. In this regard, the magnetic inspection holds a unique position. In this case a significant role is played by primary transducers, which directly perceive the effect of mechanical stresses and turn it into the electrical signal for further processing of the input information. The change of magnetic characteristics is closely connected with the physical effect on the monitored object. The advantages include the high mobility of equipment, the ability to perform control without the direct contact of transducer with the object under study. At the same time, there are several disadvantages inherent particularly in the magnetic methods – magnetoelastic hysteresis, in which there is the divergence of induction values during loading and unloading. The greatest divergence occurs in the lead-off cycle and decreases during repeated cycles. The best way is to embrace the complete information available in the hysteresis loop. Another method is not only to take measurements at one point (even if this measurement is carried out in two mutually perpendicular directions), but to perform surface sounding of the object in a certain plane. Therefore, the most efficient method is to compare the magnetic relief of loaded (in the structure) and unloaded (in reserve) pipes of one manufacturer and from one lot. Thus, using the examination method of pipelines stress condition, based on the evaluation of metal magnetic properties of pipes, creates the complex solution to the problems of reliability improvement of pipeline systems.

Magnetoelastic effect in axial stressed Ni-Zn ferrite material in Rayleigh region

Abstract The paper presents new and original results of investigation on magnetoelastic effect in Ni-Zn ferrite formed into ring core and subjected to the axial stress up to 20 MPa. The core was magnetized with relatively low magnetizing field, corresponding to the so-called Rayleigh region. The obtained results indicate, that there is a significant correlation between applied stress and magnetic properties of the material and the Ni-Zn ferrite can be utilized in development of magnetoelastic sensor of force and stress.

Encapsulation Approaches for In-Stent Wireless Magnetoelastic Sensors.

Wireless magnetoelastic sensors offer significant potential for measuring the accumulation of biomass within stents - enabling early detection prior to stent occlusion - but the encapsulation of these sensors remains a critical challenge. The encapsulation must allow the sensors to navigate the curvature and accommodate the contact forces imparted during and after the implantation procedure, while also leaving the sensor open to mechanical interaction with the biomass during the extended period of deployment. This paper is focused on the encapsulation of ribbon-like magnetoelastic sensors (12.5 mm x 1 mm x 60 μm) within plastic biliary stents (inner diameter of 2.54 mm). The compromise between two polymer-based package designs - one mechanically flexible (Type F) and one mechanically stiff (Type S) - is evaluated. The primary advantage of the Type F package is the flexibility during the delivery process while that of the Type S package is in maintaining a strong signal even when the stent is in a curved bile duct. The maximum thicknesses of the Type F and S packages are 0.53 mm and 0.74 mm, respectively. Mechanical tests show that both types protect the sensors from forces imparted by a standard introducer, and allow the encapsulated sensors to accommodate bending with a radius of curvature as small as 3 cm. The Type F package has also been tested in situ, in the bile duct of a porcine carcass. The signal is measurable with a wireless range of 10 cm, at a resonant frequency of 159 kHz and a quality factor of 397.

Monitoring and Assessing the Degradation Rate of Magnesium-Based Artificial Bone In Vitro Using a Wireless Magnetoelastic Sensor.

A magnetoelastic-based (MB) sensor was employed as a novel method to monitor and assess the degradation rate of magnesium-based artificial bone (MBAB) in vitro, which can be used as an implant to repair a bone defect, providing a quantitative method to depict the degradation rate of MBAB. MBABs were fabricated by the Pro/Engineering software and a precision machine tool using high-purity (HP) magnesium. The MB sensor was embedded in the neutral surface of MBAB by an unharmful quick adhesive, forming the MB sensor-embedded MBAB (EMBAB). The modified simulated body fluid (MSBF) media (PH = 7.4), mimicking the human internal environment, and the NaOH media (PH = 12), accelerating EMBAB’s degradation, were used to immerse the EMBAB for 15 days at 37 °C. The EMBAB was then tested daily on a self-developed experimental platform to monitor the relative output power under a 100 N external force. The results showed that the relative output power of the sensing coil gradually increased with the EMBAB’s degradation. The degradation rate of the EMBAB could be calculated on the basis of the changes of the relative output power caused by the MB sensor and of the degradation time. With the EMBAB’s degradation, an increasing strain directly worked on the MB sensor, significantly changing the value of the relative output power, which means that the EMBAB was characterized by a quick degradation rate. During the 15 days of the experiment, the degradation rates on the 7th and 15th days were 0.005 dbm/day and 0.02 dbm/day, and 0.02 dbm/day and 0.04 dbm/day in MSBF and alkaline media, respectively. Therefore, the MB sensor provides a wireless and passive method to monitor and assess the degradation rate of bone implants in vitro.