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In the current work, to identify the bending mode harmonics, 30 microns thin magnetoelastic ribbons made of metallic glass are embedded inside 6 mm thick PLA plastic cantilever beams made by 3-D printing. This is possible because the ribbons are of magnetoelastic nature and thus change their mechanical state inducing a corresponding change in their magnetic state. The ribbons are placed at four different depths, starting with zero depth at the beam’s external surface all the way inside to the beam’s mid-plane. This technique is capable of detecting seven harmonics, and remarkably, these frequencies remain the same within a marginal error of 1% for all the depths. The amplitude of the modes drops with the increase in depth but is still strong enough, except at the midplane, to be used as a sensing signal. The harmonics spectrum is the unique signature of the structure’s state; this is a proof of concept that in a contactless fashion, the embedded ribbons provide useful information about the mechanical health of a structure.
Dimitris Kouzoudis; Georgios Samourgkanidis; Christos I. Tapeinos. Contactless Detection of Natural Bending Frequencies using Embedded Metallic-Glass Ribbons inside Plastic Beams made of 3-D Printing. Recent Progress in Materials 2020, 03, 1 -1.
AMA StyleDimitris Kouzoudis, Georgios Samourgkanidis, Christos I. Tapeinos. Contactless Detection of Natural Bending Frequencies using Embedded Metallic-Glass Ribbons inside Plastic Beams made of 3-D Printing. Recent Progress in Materials. 2020; 03 (02):1-1.
Chicago/Turabian StyleDimitris Kouzoudis; Georgios Samourgkanidis; Christos I. Tapeinos. 2020. "Contactless Detection of Natural Bending Frequencies using Embedded Metallic-Glass Ribbons inside Plastic Beams made of 3-D Printing." Recent Progress in Materials 03, no. 02: 1-1.
In the current work an experimental method is used in order to calculate the diffusivity D (diffusion coefficient) of various vapors in thin zeolite films. The method is based on adsorption data from magnetoelastic sensors on top of which a zeolite layer was synthesized, and the diffusivity is extracted by fitting the data to Fick’s laws of diffusion. In particular, the method is demonstrated for two volatile organic compound (VOC) vapors on two different zeolites, the p-Xylene adsorption in Faujasite type zeolite with D = 1.89 × 10 − 13 m 2 / s at 120 ° C and the propene adsorption in Linde Type A type zeolite with D = 5.9 × 10 − 14 m 2 / s at 80 ° C , two diffusion coefficients which are extracted experimentally for first time. Our results are within the order of magnitude of other VOC/zeolite values reported in literature.
Dimitris Kouzoudis; Theodoros Baimpos; Georgios Samourgkanidis. A New Method for the Measurement of the Diffusion Coefficient of Adsorbed Vapors in Thin Zeolite Films, Based on Magnetoelastic Sensors. Sensors 2020, 20, 1 .
AMA StyleDimitris Kouzoudis, Theodoros Baimpos, Georgios Samourgkanidis. A New Method for the Measurement of the Diffusion Coefficient of Adsorbed Vapors in Thin Zeolite Films, Based on Magnetoelastic Sensors. Sensors. 2020; 20 (11):1.
Chicago/Turabian StyleDimitris Kouzoudis; Theodoros Baimpos; Georgios Samourgkanidis. 2020. "A New Method for the Measurement of the Diffusion Coefficient of Adsorbed Vapors in Thin Zeolite Films, Based on Magnetoelastic Sensors." Sensors 20, no. 11: 1.
In the current work, magnetoelastic ribbons of metallic glass alloy known as Metglas 2826MB are fully characterized as vibration sensors. The characterization involves seven different sensor parameters such as the frequency response, linearity, signal to noise ratio (SNR), quality factor, stability, repeatability and sensitivity. Two experimental setups where used for the characterization process, one for the frequency response parameter (FR setup) and one for the rest of the parameters (NFR setup). The frequency response parameter was examined for two different states of the ribbon, the non-annealed and the annealed states, and better characteristics were revealed for the annealed state. In the NFR setup, a cantilever beam (CB) was used as a vibrating platform, with two annealed Metglas ribbons attached on its free end using a double-sided tape. The 2nd, 4th and 6th bending modes of the CB were used for the characterization process. Concerning linearity, the ribbons showed an extremely linear behavior, with an average value for the adjusted R-square being Ra2=0.99995. The SNR and Quality factor parameters were studied versus the DC magnetization field of the Metglas ribbons (bias field), and the results showed that the implementation of a DC magnetic field increased the strength of the detectable signal without reducing its quality. In particular, the improvement on the detectable signal for the 2nd, 4th and 6th bending modes was 151%, 41% and 27%, respectively. The ribbons stability was examined within a time period of 2 h, with the average percentage deviation from the mean frequency being as small as 0.005% and the average change of the frequency with time as small as Fa = (1.1 ± 0.4) × 10−4 Hz/min. As for the repeatability parameter, the ribbons were subjected to alternating biasing and showed an excellent behavior during repetition cycles, with the average percentage deviation from the reference state being 0.004%, 0.002% and 0.003% for the 1st, 2nd and 3rd cycle, respectively. The last parameter studied was the sensitivity of the ribbons in detecting the shift of the natural frequencies versus CB stiffness, when a crack is introduced. Each bending mode revealed a different value of sensitivity, with the 2nd mode having the lowest and the 6th mode having the highest. The average sensitivity value among the three modes was calculated to be Sa = (38 ± 1) × 10−3 Hz/(N m−1).
Georgios Samourgkanidis; Dimitris Kouzoudis. Characterization of magnetoelastic ribbons as vibration sensors based on the measured natural frequencies of a cantilever beam. Sensors and Actuators A: Physical 2019, 301, 111711 .
AMA StyleGeorgios Samourgkanidis, Dimitris Kouzoudis. Characterization of magnetoelastic ribbons as vibration sensors based on the measured natural frequencies of a cantilever beam. Sensors and Actuators A: Physical. 2019; 301 ():111711.
Chicago/Turabian StyleGeorgios Samourgkanidis; Dimitris Kouzoudis. 2019. "Characterization of magnetoelastic ribbons as vibration sensors based on the measured natural frequencies of a cantilever beam." Sensors and Actuators A: Physical 301, no. : 111711.
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.
Georgios Samourgkanidis; Dimitris Kouzoudis. A pattern matching identification method of cracks on cantilever beams through their bending modes measured by magnetoelastic sensors. Theoretical and Applied Fracture Mechanics 2019, 103, 102266 .
AMA StyleGeorgios Samourgkanidis, Dimitris Kouzoudis. A pattern matching identification method of cracks on cantilever beams through their bending modes measured by magnetoelastic sensors. Theoretical and Applied Fracture Mechanics. 2019; 103 ():102266.
Chicago/Turabian StyleGeorgios Samourgkanidis; Dimitris Kouzoudis. 2019. "A pattern matching identification method of cracks on cantilever beams through their bending modes measured by magnetoelastic sensors." Theoretical and Applied Fracture Mechanics 103, no. : 102266.
The main parameters of magnetoelastic resonators in the detection of chemical (i.e., salts, gases, etc.) or biological (i.e., bacteria, phages, etc.) agents are the sensitivity S (or external agent change magnitude per Hz change in the resonance frequency) and the quality factor Q of the resonance. We present an extensive study on the experimental determination of the Q factor in such magnetoelastic resonant platforms, using three different strategies: (a) analyzing the real and imaginary components of the susceptibility at resonance; (b) numerical fitting of the modulus of the susceptibility; (c) using an exact mathematical expression for the real part of the susceptibility. Q values obtained by the three methods are analyzed and discussed, aiming to establish the most adequate one to accurately determine the quality factor of the magnetoelastic resonance.
Ana Catarina Lopes; Ariane Sagasti; Andoni Lasheras; Virginia Muto; Jon Gutiérrez; Dimitris Kouzoudis; José Manuel Barandiarán. Accurate Determination of the Q Quality Factor in Magnetoelastic Resonant Platforms for Advanced Biological Detection. Sensors 2018, 18, 887 .
AMA StyleAna Catarina Lopes, Ariane Sagasti, Andoni Lasheras, Virginia Muto, Jon Gutiérrez, Dimitris Kouzoudis, José Manuel Barandiarán. Accurate Determination of the Q Quality Factor in Magnetoelastic Resonant Platforms for Advanced Biological Detection. Sensors. 2018; 18 (3):887.
Chicago/Turabian StyleAna Catarina Lopes; Ariane Sagasti; Andoni Lasheras; Virginia Muto; Jon Gutiérrez; Dimitris Kouzoudis; José Manuel Barandiarán. 2018. "Accurate Determination of the Q Quality Factor in Magnetoelastic Resonant Platforms for Advanced Biological Detection." Sensors 18, no. 3: 887.
In the present work, a nanostructured ZnO layer was synthesized onto a Metglas magnetoelastic ribbon to immobilize hemoglobin (Hb) on it and study the Hb’s electrochemical behavior towards hydrogen peroxide. Hb oxidation by H2O2 was monitored simultaneously by two different techniques: Cyclic Voltammetry (CV) and Magnetoelastic Resonance (MR). The Metglas/ZnO/Hb system was simultaneously used as a working electrode for the CV scans and as a magnetoelastic sensor excited by external coils, which drive it to resonance and interrogate it. The ZnO nanoparticles for the ZnO layer were grown hydrothermally and fully characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and photoluminescence (PL). Additionally, the ZnO layer’s elastic modulus was measured using a new method, which makes use of the Metglas substrate. For the detection experiments, the electrochemical cell was performed with a glass vial, where the three electrodes (working, counter and reference) were immersed into PBS (Phosphate Buffer Solution) solution and small H2O2 drops were added, one at a time. CV scans were taken every 30 s and 5 min after the addition of each drop and meanwhile a magnetoelastic measurement was taken by the external coils. The CV plots reveal direct electrochemical behavior of Hb and display good electrocatalytic response to the reduction of H2O2. The measured catalysis currents increase linearly with the H2O2 concentration in a wide range of 25–350 μM with a correlation coefficient 0.99. The detection limit is 25–50 μM. Moreover, the Metglas/ZnO/Hb electrode displays rapid response (30 s) to H2O2, and exhibits good stability and reproducibility of the measurements. On the other hand, the magnetoelastic measurements show a small linear mass increase versus the H2O2 concentration with a slope of 152 ng/μM, which is probably due to H2O2 adsorption in ZnO during the electrochemical reaction. No such effects were detected during the control experiment when only PBS solution was present for a long time.
Ariane Sagasti; Nikolaos Bouropoulos; Dimitris Kouzoudis; Apostolos Panagiotopoulos; Emmanuel Topoglidis; Jon Gutiérrez. Nanostructured ZnO in a Metglas/ZnO/Hemoglobin Modified Electrode to Detect the Oxidation of the Hemoglobin Simultaneously by Cyclic Voltammetry and Magnetoelastic Resonance. Materials 2017, 10, 849 .
AMA StyleAriane Sagasti, Nikolaos Bouropoulos, Dimitris Kouzoudis, Apostolos Panagiotopoulos, Emmanuel Topoglidis, Jon Gutiérrez. Nanostructured ZnO in a Metglas/ZnO/Hemoglobin Modified Electrode to Detect the Oxidation of the Hemoglobin Simultaneously by Cyclic Voltammetry and Magnetoelastic Resonance. Materials. 2017; 10 (8):849.
Chicago/Turabian StyleAriane Sagasti; Nikolaos Bouropoulos; Dimitris Kouzoudis; Apostolos Panagiotopoulos; Emmanuel Topoglidis; Jon Gutiérrez. 2017. "Nanostructured ZnO in a Metglas/ZnO/Hemoglobin Modified Electrode to Detect the Oxidation of the Hemoglobin Simultaneously by Cyclic Voltammetry and Magnetoelastic Resonance." Materials 10, no. 8: 849.
Dimitris Kouzoudis; Vladimiros Nikolakis. The use of a non-linear model for a more realistic calculation of the “ΔE effect” in magnetoelastic ribbons. Journal of Magnetism and Magnetic Materials 2015, 395, 59 -66.
AMA StyleDimitris Kouzoudis, Vladimiros Nikolakis. The use of a non-linear model for a more realistic calculation of the “ΔE effect” in magnetoelastic ribbons. Journal of Magnetism and Magnetic Materials. 2015; 395 ():59-66.
Chicago/Turabian StyleDimitris Kouzoudis; Vladimiros Nikolakis. 2015. "The use of a non-linear model for a more realistic calculation of the “ΔE effect” in magnetoelastic ribbons." Journal of Magnetism and Magnetic Materials 395, no. : 59-66.
Theodoros Baimpos; Vassiliki Tsukala; Vladimiros Nikolakis; Dimitris Kouzoudis. A Modified Method for the Calculation of the Humidity Adsorption Stresses Inside Zeolite Films Using Magnetoelastic Sensors. Sensor Letters 2012, 10, 879 -885.
AMA StyleTheodoros Baimpos, Vassiliki Tsukala, Vladimiros Nikolakis, Dimitris Kouzoudis. A Modified Method for the Calculation of the Humidity Adsorption Stresses Inside Zeolite Films Using Magnetoelastic Sensors. Sensor Letters. 2012; 10 (3):879-885.
Chicago/Turabian StyleTheodoros Baimpos; Vassiliki Tsukala; Vladimiros Nikolakis; Dimitris Kouzoudis. 2012. "A Modified Method for the Calculation of the Humidity Adsorption Stresses Inside Zeolite Films Using Magnetoelastic Sensors." Sensor Letters 10, no. 3: 879-885.
Theodoros Baimpos; Vladimiros Nikolakis; Dimitris Kouzoudis. A new method for measuring the adsorption induced stresses of zeolite films using magnetoelastic sensors. Journal of Membrane Science 2012, 390-391, 130 -140.
AMA StyleTheodoros Baimpos, Vladimiros Nikolakis, Dimitris Kouzoudis. A new method for measuring the adsorption induced stresses of zeolite films using magnetoelastic sensors. Journal of Membrane Science. 2012; 390-391 ():130-140.
Chicago/Turabian StyleTheodoros Baimpos; Vladimiros Nikolakis; Dimitris Kouzoudis. 2012. "A new method for measuring the adsorption induced stresses of zeolite films using magnetoelastic sensors." Journal of Membrane Science 390-391, no. : 130-140.
Faujasite (FAU) has been used as the sensitive recognition layer on the outer surfaces of a Metglas magnetoelastic strip for the detection of volatile organic compounds (VOCs). The sensor combines the electromagnetic properties of the magnetoelastic material with the adsorption properties of the FAU crystals. At 120oC and at 500 ppm, the sensor's response in decreasing order is: ethyl-acetate, p-xylene, o- xylene ≈ benzene, c-hexane ≈ n-hexane. This order is not fully in agreement with the order of the mass loadings calculated from adsorption isotherms, probably due to changes of the zeolite film mechanical properties (Young modulus or/and deformations of the faujasite unit cell dimension) induced by the adsorbed molecules. The Minimum Detection Limits (MDL) of c-hexane, p-xylene and o-xylene at 120oC were 166, 17 and 5 ppm respectively.
Dimitris Kouzoudis; Theodoros Baimpos; Vladimiros Nikolakis. Detection of Hazardous VOCs using a Zeolite FAU/Metglas Magnetoelastic Sensor. Procedia Engineering 2011, 25, 1621 -1624.
AMA StyleDimitris Kouzoudis, Theodoros Baimpos, Vladimiros Nikolakis. Detection of Hazardous VOCs using a Zeolite FAU/Metglas Magnetoelastic Sensor. Procedia Engineering. 2011; 25 ():1621-1624.
Chicago/Turabian StyleDimitris Kouzoudis; Theodoros Baimpos; Vladimiros Nikolakis. 2011. "Detection of Hazardous VOCs using a Zeolite FAU/Metglas Magnetoelastic Sensor." Procedia Engineering 25, no. : 1621-1624.
Theodoros Baimpos; Dimitris Kouzoudis; Vladimiros Nikolakis. Use of a Zeolite LTA Film for the Selective Detection of Light Hydrocarbons. Science of Advanced Materials 2010, 2, 215 -218.
AMA StyleTheodoros Baimpos, Dimitris Kouzoudis, Vladimiros Nikolakis. Use of a Zeolite LTA Film for the Selective Detection of Light Hydrocarbons. Science of Advanced Materials. 2010; 2 (2):215-218.
Chicago/Turabian StyleTheodoros Baimpos; Dimitris Kouzoudis; Vladimiros Nikolakis. 2010. "Use of a Zeolite LTA Film for the Selective Detection of Light Hydrocarbons." Science of Advanced Materials 2, no. 2: 215-218.
In this work, the commercial polymer BAYHYDROL-110 has been employed as the analyte-responsive recognition layer on a magnetoelastic sensor used to detect several volatile organic compounds. The sensor exhibits enhanced selectivity to o-xylene and p-xylene compared to six other tested volatile organic compounds as well as to humidity. The sensitivities to o-xylene and p-xylene were −0.27 and −0.19 kHz/ppm of vapor concentration in air, respectively. The sensor exhibits excellent repeatability and stability over a period of at least 75 days, and relatively quick response times (on the order of a minute), but rather low recovery times (in the range of several minutes). The sensor's sensitivity increases linearly with the mass of the polymer, but it is only slightly dependent on the sensor's length.
Theodoros Baimpos; Panagiotis Boutikos; Vladimiros Nikolakis; Dimitris Kouzoudis. A polymer-Metglas sensor used to detect volatile organic compounds. Sensors and Actuators A: Physical 2010, 158, 249 -253.
AMA StyleTheodoros Baimpos, Panagiotis Boutikos, Vladimiros Nikolakis, Dimitris Kouzoudis. A polymer-Metglas sensor used to detect volatile organic compounds. Sensors and Actuators A: Physical. 2010; 158 (2):249-253.
Chicago/Turabian StyleTheodoros Baimpos; Panagiotis Boutikos; Vladimiros Nikolakis; Dimitris Kouzoudis. 2010. "A polymer-Metglas sensor used to detect volatile organic compounds." Sensors and Actuators A: Physical 158, no. 2: 249-253.
A novel method is presented for measuring the elastic properties of zeolite films using magnetoelastic sensors. The method is relatively simple and can be used to determine the effect of adsorbed molecules on the mechanical properties of the zeolite film. It is demonstrated using NaX films grown on Metglas ribbons. Measurements were taken as a function of temperature (10−40 °C) and gas (CO2, N2, vacuum) for a range of sensors with different faujasite masses (0.25−8.0 mg). For each temperature and gas, the modulus of elasticity of the faujasite crystalline film was extracted by analyzing the measurements as a function of film thickness. For all temperatures examined, it was found that the elastic modulus of the NaX films in vacuum was 38.7 ± 1.7 GPa. On the other hand, in the presence of N2, it varied between ∼24 and ∼38 GPa and, when in contact with CO2, between ∼39 and ∼52 GPa. Our results show for first time that the adsorption of gases in zeolites might induce changes in the elastic properties of the zeolite crystals. Finally, even though this method was applied to a zeolite film, it is quite general, and it can be used for measuring the elastic modulus of any microporous or mesoporous film.
Theodoros Baimpos; Ioannis G. Giannakopoulos; Vladimiros Nikolakis; Dimitris Kouzoudis. Effect of Gas Adsorption on the Elastic Properties of Faujasite Films Measured Using Magnetoelastic Sensors. Chemistry of Materials 2008, 20, 1470 -1475.
AMA StyleTheodoros Baimpos, Ioannis G. Giannakopoulos, Vladimiros Nikolakis, Dimitris Kouzoudis. Effect of Gas Adsorption on the Elastic Properties of Faujasite Films Measured Using Magnetoelastic Sensors. Chemistry of Materials. 2008; 20 (4):1470-1475.
Chicago/Turabian StyleTheodoros Baimpos; Ioannis G. Giannakopoulos; Vladimiros Nikolakis; Dimitris Kouzoudis. 2008. "Effect of Gas Adsorption on the Elastic Properties of Faujasite Films Measured Using Magnetoelastic Sensors." Chemistry of Materials 20, no. 4: 1470-1475.