Nurul Akmal Che Lah | Universiti Malaysia Pahang (UMP) (original) (raw)

Papers by Nurul Akmal Che Lah

Surfaces and interfaces, May 1, 2024

Microbial Cell Factories, Feb 17, 2021

With the long-term goal of developing an ultra-sensitive microcantilever-based biosensor for vers... more With the long-term goal of developing an ultra-sensitive microcantilever-based biosensor for versatile biomarker detection, new controlled bioreceptor-analytes systems are being explored to overcome the disadvantages of conventional ones. Gold (Au) microwires have been used as a probe to overcome the tolerance problem that occurs in response to changes in environmental conditions. However, the cytotoxicity of Au microwires is still unclear. Here, we examined the cytotoxicity of Au microwires systems using both commercial and as-synthesised Au microwires. In vitro experiments show that commercial Au microwires with an average quoted length of 5.6 µm are highly toxic against Gram-negative Escherichia coli (E. coli) at 50 µg/mL. However, this toxicity is due to the presence of CTAB surfactant not by the microwires. Conversely, the as-synthesised Au microwires show non-cytotoxicity even at the maximum viable concentration (330 µg/mL). These findings may lead to the development of potentially life-saving cytotoxicity-free biosensors for an early diagnostic of potential diseases.

Research Square (Research Square), Aug 2, 2020

With the long-term goal of developing an ultra-sensitive microcantilever-based nanobiosensor for ... more With the long-term goal of developing an ultra-sensitive microcantilever-based nanobiosensor for versatile biomarker detection, new controlled bioreceptor-analytes systems are being explored to overcome the disadvantages of conventional ones. Gold nanowires (AuNWs) have been used as a probe to overcome the tolerance problem that occurs in response to changes in environmental conditions. However, the cytotoxicity of AuNWs is still unclear. Here, we examined the cytotoxicity of AuNWs systems using both commercial and as-synthesised AuNWs. In vitro experiments show that commercial AuNWs with an average quoted length of 6 µm are highly toxic against Gram-negative Escherichia coli (E. coli) at 50 µg/ml. However, this toxicity is due to the presence of CTAB surfactant no by the nanostructure. Conversely, the as-synthesised AuNWs with an average length of 9.5 µm show non-cytotoxicity even at the maximum viable concentration (330 µg/ml). These ndings may lead to the development of potentially life-saving cytotoxicity-free nanobiosensors for an early diagnostic of potential diseases.

Journal of Telecommunication, Electronic and Computer Engineering, Jan 18, 2018

A high-homogeneity excitation coil with a resonant circuit for AC magnetometer is developed. A so... more A high-homogeneity excitation coil with a resonant circuit for AC magnetometer is developed. A solenoid coil is designed to produce a high-homogeneity and strong excitation field using a resonant frequency method. The solenoid coil is fabricated with a Litz wire to suppress the increase of AC resistance due to the skin and proximity effects in the highfrequency region. The Litz wire is composed of 60 strands of copper wires with 0.1-mm diameter. The resonant frequency method is applied to cancel the reactance component by connecting the excitation coil with a capacitor in a series configuration. To enable excitation of the magnetic field at multiple frequencies, a resonant circuit consists of multiple values of resonant capacitors is constructed. The fabricated excitation coil showed a high homogeneity of the magnetic field and was able to maintain a constant resonant current up to 32.5 kHz.

Engineering research express, Jun 1, 2022

In this study, we report a development of a benchtop induction-based AC magnetometer to realize a... more In this study, we report a development of a benchtop induction-based AC magnetometer to realize a simple, wideband, and sensitive AC magnetometer for bio-sensing applications and characterization of magnetic nanoparticles (MNPs). We investigate the inductance and parasitic capacitance of six different pickup coil geometries and compare their sensitivity and usable frequency range. In the pickup coil design, the number of turns and coil section separation are varied from 200 to 400 turns, and 1 to 4 sections, respectively. We find that the usable frequency range is greatly affected by the pickup coil’s inductance due to the self-resonance phenomena compared to their parasitic capacitance. A low noise instrument amplifier circuit (AD8429, Analog Devices, USA) was integrated and fabricated on a printed circuit board to amplify the weak signal from the pickup coil. We also implement a generalized Goertzel algorithm to achieve fast signal amplitude and phase extractions at a frequency. The developed magnetometer shows a sensitivity of 10−8 Am2/√Hz at 6 Hz and a frequency range of up to 158 kHz. Using the developed AC magnetometer, we demonstrate the viscosity effect on the frequency response of thermally blocked, single-core nanoparticles (SHP30, Ocean Nanotech, USA) in glycerol solutions. The excitation frequency is swept from 5 Hz to 158 kHz at a field amplitude of 0.55 mTpp within the acquisition time of 5 min (51 points). As a result, the viscosity change is confirmed by the peak shifting in the imaginary magnetization curve towards lower frequency values when the wt/V% of the glycerol solution is increased. The hydrodynamic size and the average anisotropy energy ratio σ are estimated to be 60.6 nm and 25, respectively, from the complex AC magnetization. It can be expected that the developed AC magnetometer can be a valuable tool in providing a fast and reliable assessment of MNPs for bio-sensing applications.

Surfaces and Interfaces, Jun 1, 2023

2018 IEEE International Magnetics Conference (INTERMAG), Apr 1, 2018

Advanced Science Letters, Nov 1, 2017

In the recent years, with the fast advancement in the fields associated with nanoscience and nano... more In the recent years, with the fast advancement in the fields associated with nanoscience and nanotechnology, metal nanowires, in specific have received enormous attention among researchers due to their fascinating properties and applications. In this study, the Young Modulus and failure behavior of Nickel (Ni) nanowires 7.04 nm in diameter with eight (8) different lengths (

Research Square (Research Square), Nov 19, 2020

With the long-term goal of developing an ultra-sensitive microcantilever-based biosensor for vers... more With the long-term goal of developing an ultra-sensitive microcantilever-based biosensor for versatile biomarker detection, new controlled bioreceptor-analytes systems are being explored to overcome the disadvantages of conventional ones. Gold (Au) microwires have been used as a probe to overcome the tolerance problem that occurs in response to changes in environmental conditions. However, the cytotoxicity of Au microwires is still unclear. Here, we examined the cytotoxicity of Au microwires systems using both commercial and as-synthesised Au microwires. In vitro experiments show that commercial Au microwires with an average quoted length of 5.6 µm are highly toxic against Gram-negative Escherichia coli (E. coli) at 50 µg/ml. However, this toxicity is due to the presence of CTAB surfactant not by the microwires. Conversely, the as-synthesised Au microwires show non-cytotoxicity even at the maximum viable concentration (330µg/ml). These ndings may lead to the development of potentially life-saving cytotoxicity-free biosensors for an early diagnostic of potential diseases.

Research Square (Research Square), Oct 27, 2020

With the long-term goal of developing an ultra-sensitive microcantilever-based nano biosensor for... more With the long-term goal of developing an ultra-sensitive microcantilever-based nano biosensor for versatile biomarker detection, new controlled bioreceptor-analytes systems are being explored to overcome the disadvantages of conventional ones. Gold nanowires (AuNWs) have been used as a probe to overcome the tolerance problem that occurs in response to changes in environmental conditions. However, the cytotoxicity of AuNWs is still unclear. Here, we examined the cytotoxicity of AuNWs systems using both commercial and as-synthesised AuNWs. In vitro experiments show that commercial AuNWs with an average quoted length of 6 µm are highly toxic against Gram-negative Escherichia coli (E. coli) at 50 µg/ml. However, this toxicity is due to the presence of CTAB surfactant not by the nanostructure. Conversely, the as-synthesised AuNWs with an average length of 9.5 µm show non-cytotoxicity even at the maximum viable concentration (330µg/ml). These ndings may lead to the development of potentially life-saving cytotoxicity-free nano biosensors for an early diagnostic of potential diseases.

Lecture notes in mechanical engineering, 2018

Characterization of magnetic nanoparticles is crucial in order to optimize them for different app... more Characterization of magnetic nanoparticles is crucial in order to optimize them for different applications requiring specific characteristics. In this article, we report a characterization system using AC susceptibility method. An AC magnetometer system which is composed of the induction coil and resonant capacitors is developed to evaluate the performance of the magnetic nanoparticles. The induction coil consists of excitation and detection coil. The excitation coil is designed with solenoid coils and fabricated with a Litz wire which is composed of 60 strands of copper wire with 0.1 mm diameter to reduce the increase of AC resistance at high frequency. The detection coil is designed to be a first-order differential coil which is used to reduce the environmental noise and cancel the excitation magnetic field. The detection coil is fabricated with a copper wire and it is placed at the center of the excitation coil. The excitation coil is connected to the resonant capacitors to cancel the reactant component and to permit the high magnetic field in the high-frequency region. The resonant capacitors are fabricated with multiple values of capacitors. When the developed system is in the resonant mode, the current flow is constant up to the frequency of 32.5 kHz. The developed system can evaluate the magnetic nanoparticles at different frequency responses. Using the developed system, it is shown that the Neel particles exist inside the solution of magnetic nanoparticles used in this study.

Materials Today: Proceedings

2023 International Conference on System Science and Engineering (ICSSE)

Engineering Research Express

In this study, we report a development of a benchtop induction-based AC magnetometer to realize a... more In this study, we report a development of a benchtop induction-based AC magnetometer to realize a simple, wideband, and sensitive AC magnetometer for bio-sensing applications and characterization of magnetic nanoparticles (MNPs). We investigate the inductance and parasitic capacitance of six different pickup coil geometries and compare their sensitivity and usable frequency range. In the pickup coil design, the number of turns and coil section separation are varied from 200 to 400 turns, and 1 to 4 sections, respectively. We find that the usable frequency range is greatly affected by the pickup coil’s inductance due to the self-resonance phenomena compared to their parasitic capacitance. A low noise instrument amplifier circuit (AD8429, Analog Devices, USA) was integrated and fabricated on a printed circuit board to amplify the weak signal from the pickup coil. We also implement a generalized Goertzel algorithm to achieve fast signal amplitude and phase extractions at a frequency. T...

2017 IEEE 8th Control and System Graduate Research Colloquium (ICSGRC), 2017

A compact and sensitive AC magnetometer is developed for evaluation of magnetic nanoparticles sol... more A compact and sensitive AC magnetometer is developed for evaluation of magnetic nanoparticles solution. The developed AC magnetometer consists of two main parts; excitation and detection coil systems. A Helmholtz coil configuration was used as the excitation coil to ensure a high homogeneity of excitation magnetic field. To reduce AC resistance due to eddy current effect in the wire of the excitation coil at a high-frequency region, a Litz wire was used. The Litz wire was composed of 60 strands of copper wires with 0.1-mm diameter. For the detection coil, a first order axial differential coil was used so that environmental noises can be canceled. The detection coil consisted of two 1000-turn copper coils and they were connected in series. The fabricated excitation coil showed a high homogeneity along its axis with the high excitation magnetic field. The sensitivity of the developed system increased with respect to frequency. The magnetic noise of the detection unit showed a 1/f noise characteristic and a sensitivity of 10 10 Am 2 at 100 Hz was showed by the developed system. To demonstrate the feasibility of the developed system, harmonics of Nickel nanowires was measured. The harmonics generation increased with the increasing amplitude of excitation field. It can be expected that an extremely sensitive characterization of MNP is possible using the developed system.

Journal of Telecommunication, Electronic and Computer Engineering, Jan 18, 2018

A high-homogeneity excitation coil with a resonant circuit for AC magnetometer is developed. A so... more A high-homogeneity excitation coil with a resonant circuit for AC magnetometer is developed. A solenoid coil is designed to produce a high-homogeneity and strong excitation field using a resonant frequency method. The solenoid coil is fabricated with a Litz wire to suppress the increase of AC resistance due to the skin and proximity effects in the highfrequency region. The Litz wire is composed of 60 strands of copper wires with 0.1-mm diameter. The resonant frequency method is applied to cancel the reactance component by connecting the excitation coil with a capacitor in a series configuration. To enable excitation of the magnetic field at multiple frequencies, a resonant circuit consists of multiple values of resonant capacitors is constructed. The fabricated excitation coil showed a high homogeneity of the magnetic field and was able to maintain a constant resonant current up to 32.5 kHz.

Engineering research express, Jun 1, 2022

In this study, we report a development of a benchtop induction-based AC magnetometer to realize a... more In this study, we report a development of a benchtop induction-based AC magnetometer to realize a simple, wideband, and sensitive AC magnetometer for bio-sensing applications and characterization of magnetic nanoparticles (MNPs). We investigate the inductance and parasitic capacitance of six different pickup coil geometries and compare their sensitivity and usable frequency range. In the pickup coil design, the number of turns and coil section separation are varied from 200 to 400 turns, and 1 to 4 sections, respectively. We find that the usable frequency range is greatly affected by the pickup coil’s inductance due to the self-resonance phenomena compared to their parasitic capacitance. A low noise instrument amplifier circuit (AD8429, Analog Devices, USA) was integrated and fabricated on a printed circuit board to amplify the weak signal from the pickup coil. We also implement a generalized Goertzel algorithm to achieve fast signal amplitude and phase extractions at a frequency. The developed magnetometer shows a sensitivity of 10−8 Am2/√Hz at 6 Hz and a frequency range of up to 158 kHz. Using the developed AC magnetometer, we demonstrate the viscosity effect on the frequency response of thermally blocked, single-core nanoparticles (SHP30, Ocean Nanotech, USA) in glycerol solutions. The excitation frequency is swept from 5 Hz to 158 kHz at a field amplitude of 0.55 mTpp within the acquisition time of 5 min (51 points). As a result, the viscosity change is confirmed by the peak shifting in the imaginary magnetization curve towards lower frequency values when the wt/V% of the glycerol solution is increased. The hydrodynamic size and the average anisotropy energy ratio σ are estimated to be 60.6 nm and 25, respectively, from the complex AC magnetization. It can be expected that the developed AC magnetometer can be a valuable tool in providing a fast and reliable assessment of MNPs for bio-sensing applications.

Surfaces and Interfaces, Jun 1, 2023

2018 IEEE International Magnetics Conference (INTERMAG), Apr 1, 2018

Advanced Science Letters, Nov 1, 2017

In the recent years, with the fast advancement in the fields associated with nanoscience and nano... more In the recent years, with the fast advancement in the fields associated with nanoscience and nanotechnology, metal nanowires, in specific have received enormous attention among researchers due to their fascinating properties and applications. In this study, the Young Modulus and failure behavior of Nickel (Ni) nanowires 7.04 nm in diameter with eight (8) different lengths (

Surfaces and interfaces, May 1, 2024

Microbial Cell Factories, Feb 17, 2021

With the long-term goal of developing an ultra-sensitive microcantilever-based biosensor for vers... more With the long-term goal of developing an ultra-sensitive microcantilever-based biosensor for versatile biomarker detection, new controlled bioreceptor-analytes systems are being explored to overcome the disadvantages of conventional ones. Gold (Au) microwires have been used as a probe to overcome the tolerance problem that occurs in response to changes in environmental conditions. However, the cytotoxicity of Au microwires is still unclear. Here, we examined the cytotoxicity of Au microwires systems using both commercial and as-synthesised Au microwires. In vitro experiments show that commercial Au microwires with an average quoted length of 5.6 µm are highly toxic against Gram-negative Escherichia coli (E. coli) at 50 µg/mL. However, this toxicity is due to the presence of CTAB surfactant not by the microwires. Conversely, the as-synthesised Au microwires show non-cytotoxicity even at the maximum viable concentration (330 µg/mL). These findings may lead to the development of potentially life-saving cytotoxicity-free biosensors for an early diagnostic of potential diseases.

Research Square (Research Square), Aug 2, 2020

With the long-term goal of developing an ultra-sensitive microcantilever-based nanobiosensor for ... more With the long-term goal of developing an ultra-sensitive microcantilever-based nanobiosensor for versatile biomarker detection, new controlled bioreceptor-analytes systems are being explored to overcome the disadvantages of conventional ones. Gold nanowires (AuNWs) have been used as a probe to overcome the tolerance problem that occurs in response to changes in environmental conditions. However, the cytotoxicity of AuNWs is still unclear. Here, we examined the cytotoxicity of AuNWs systems using both commercial and as-synthesised AuNWs. In vitro experiments show that commercial AuNWs with an average quoted length of 6 µm are highly toxic against Gram-negative Escherichia coli (E. coli) at 50 µg/ml. However, this toxicity is due to the presence of CTAB surfactant no by the nanostructure. Conversely, the as-synthesised AuNWs with an average length of 9.5 µm show non-cytotoxicity even at the maximum viable concentration (330 µg/ml). These ndings may lead to the development of potentially life-saving cytotoxicity-free nanobiosensors for an early diagnostic of potential diseases.

Journal of Telecommunication, Electronic and Computer Engineering, Jan 18, 2018

A high-homogeneity excitation coil with a resonant circuit for AC magnetometer is developed. A so... more A high-homogeneity excitation coil with a resonant circuit for AC magnetometer is developed. A solenoid coil is designed to produce a high-homogeneity and strong excitation field using a resonant frequency method. The solenoid coil is fabricated with a Litz wire to suppress the increase of AC resistance due to the skin and proximity effects in the highfrequency region. The Litz wire is composed of 60 strands of copper wires with 0.1-mm diameter. The resonant frequency method is applied to cancel the reactance component by connecting the excitation coil with a capacitor in a series configuration. To enable excitation of the magnetic field at multiple frequencies, a resonant circuit consists of multiple values of resonant capacitors is constructed. The fabricated excitation coil showed a high homogeneity of the magnetic field and was able to maintain a constant resonant current up to 32.5 kHz.

Engineering research express, Jun 1, 2022

In this study, we report a development of a benchtop induction-based AC magnetometer to realize a... more In this study, we report a development of a benchtop induction-based AC magnetometer to realize a simple, wideband, and sensitive AC magnetometer for bio-sensing applications and characterization of magnetic nanoparticles (MNPs). We investigate the inductance and parasitic capacitance of six different pickup coil geometries and compare their sensitivity and usable frequency range. In the pickup coil design, the number of turns and coil section separation are varied from 200 to 400 turns, and 1 to 4 sections, respectively. We find that the usable frequency range is greatly affected by the pickup coil’s inductance due to the self-resonance phenomena compared to their parasitic capacitance. A low noise instrument amplifier circuit (AD8429, Analog Devices, USA) was integrated and fabricated on a printed circuit board to amplify the weak signal from the pickup coil. We also implement a generalized Goertzel algorithm to achieve fast signal amplitude and phase extractions at a frequency. The developed magnetometer shows a sensitivity of 10−8 Am2/√Hz at 6 Hz and a frequency range of up to 158 kHz. Using the developed AC magnetometer, we demonstrate the viscosity effect on the frequency response of thermally blocked, single-core nanoparticles (SHP30, Ocean Nanotech, USA) in glycerol solutions. The excitation frequency is swept from 5 Hz to 158 kHz at a field amplitude of 0.55 mTpp within the acquisition time of 5 min (51 points). As a result, the viscosity change is confirmed by the peak shifting in the imaginary magnetization curve towards lower frequency values when the wt/V% of the glycerol solution is increased. The hydrodynamic size and the average anisotropy energy ratio σ are estimated to be 60.6 nm and 25, respectively, from the complex AC magnetization. It can be expected that the developed AC magnetometer can be a valuable tool in providing a fast and reliable assessment of MNPs for bio-sensing applications.

Surfaces and Interfaces, Jun 1, 2023

2018 IEEE International Magnetics Conference (INTERMAG), Apr 1, 2018

Advanced Science Letters, Nov 1, 2017

In the recent years, with the fast advancement in the fields associated with nanoscience and nano... more In the recent years, with the fast advancement in the fields associated with nanoscience and nanotechnology, metal nanowires, in specific have received enormous attention among researchers due to their fascinating properties and applications. In this study, the Young Modulus and failure behavior of Nickel (Ni) nanowires 7.04 nm in diameter with eight (8) different lengths (

Research Square (Research Square), Nov 19, 2020

With the long-term goal of developing an ultra-sensitive microcantilever-based biosensor for vers... more With the long-term goal of developing an ultra-sensitive microcantilever-based biosensor for versatile biomarker detection, new controlled bioreceptor-analytes systems are being explored to overcome the disadvantages of conventional ones. Gold (Au) microwires have been used as a probe to overcome the tolerance problem that occurs in response to changes in environmental conditions. However, the cytotoxicity of Au microwires is still unclear. Here, we examined the cytotoxicity of Au microwires systems using both commercial and as-synthesised Au microwires. In vitro experiments show that commercial Au microwires with an average quoted length of 5.6 µm are highly toxic against Gram-negative Escherichia coli (E. coli) at 50 µg/ml. However, this toxicity is due to the presence of CTAB surfactant not by the microwires. Conversely, the as-synthesised Au microwires show non-cytotoxicity even at the maximum viable concentration (330µg/ml). These ndings may lead to the development of potentially life-saving cytotoxicity-free biosensors for an early diagnostic of potential diseases.

Research Square (Research Square), Oct 27, 2020

With the long-term goal of developing an ultra-sensitive microcantilever-based nano biosensor for... more With the long-term goal of developing an ultra-sensitive microcantilever-based nano biosensor for versatile biomarker detection, new controlled bioreceptor-analytes systems are being explored to overcome the disadvantages of conventional ones. Gold nanowires (AuNWs) have been used as a probe to overcome the tolerance problem that occurs in response to changes in environmental conditions. However, the cytotoxicity of AuNWs is still unclear. Here, we examined the cytotoxicity of AuNWs systems using both commercial and as-synthesised AuNWs. In vitro experiments show that commercial AuNWs with an average quoted length of 6 µm are highly toxic against Gram-negative Escherichia coli (E. coli) at 50 µg/ml. However, this toxicity is due to the presence of CTAB surfactant not by the nanostructure. Conversely, the as-synthesised AuNWs with an average length of 9.5 µm show non-cytotoxicity even at the maximum viable concentration (330µg/ml). These ndings may lead to the development of potentially life-saving cytotoxicity-free nano biosensors for an early diagnostic of potential diseases.

Lecture notes in mechanical engineering, 2018

Characterization of magnetic nanoparticles is crucial in order to optimize them for different app... more Characterization of magnetic nanoparticles is crucial in order to optimize them for different applications requiring specific characteristics. In this article, we report a characterization system using AC susceptibility method. An AC magnetometer system which is composed of the induction coil and resonant capacitors is developed to evaluate the performance of the magnetic nanoparticles. The induction coil consists of excitation and detection coil. The excitation coil is designed with solenoid coils and fabricated with a Litz wire which is composed of 60 strands of copper wire with 0.1 mm diameter to reduce the increase of AC resistance at high frequency. The detection coil is designed to be a first-order differential coil which is used to reduce the environmental noise and cancel the excitation magnetic field. The detection coil is fabricated with a copper wire and it is placed at the center of the excitation coil. The excitation coil is connected to the resonant capacitors to cancel the reactant component and to permit the high magnetic field in the high-frequency region. The resonant capacitors are fabricated with multiple values of capacitors. When the developed system is in the resonant mode, the current flow is constant up to the frequency of 32.5 kHz. The developed system can evaluate the magnetic nanoparticles at different frequency responses. Using the developed system, it is shown that the Neel particles exist inside the solution of magnetic nanoparticles used in this study.

Materials Today: Proceedings

2023 International Conference on System Science and Engineering (ICSSE)

Engineering Research Express

In this study, we report a development of a benchtop induction-based AC magnetometer to realize a... more In this study, we report a development of a benchtop induction-based AC magnetometer to realize a simple, wideband, and sensitive AC magnetometer for bio-sensing applications and characterization of magnetic nanoparticles (MNPs). We investigate the inductance and parasitic capacitance of six different pickup coil geometries and compare their sensitivity and usable frequency range. In the pickup coil design, the number of turns and coil section separation are varied from 200 to 400 turns, and 1 to 4 sections, respectively. We find that the usable frequency range is greatly affected by the pickup coil’s inductance due to the self-resonance phenomena compared to their parasitic capacitance. A low noise instrument amplifier circuit (AD8429, Analog Devices, USA) was integrated and fabricated on a printed circuit board to amplify the weak signal from the pickup coil. We also implement a generalized Goertzel algorithm to achieve fast signal amplitude and phase extractions at a frequency. T...

2017 IEEE 8th Control and System Graduate Research Colloquium (ICSGRC), 2017

A compact and sensitive AC magnetometer is developed for evaluation of magnetic nanoparticles sol... more A compact and sensitive AC magnetometer is developed for evaluation of magnetic nanoparticles solution. The developed AC magnetometer consists of two main parts; excitation and detection coil systems. A Helmholtz coil configuration was used as the excitation coil to ensure a high homogeneity of excitation magnetic field. To reduce AC resistance due to eddy current effect in the wire of the excitation coil at a high-frequency region, a Litz wire was used. The Litz wire was composed of 60 strands of copper wires with 0.1-mm diameter. For the detection coil, a first order axial differential coil was used so that environmental noises can be canceled. The detection coil consisted of two 1000-turn copper coils and they were connected in series. The fabricated excitation coil showed a high homogeneity along its axis with the high excitation magnetic field. The sensitivity of the developed system increased with respect to frequency. The magnetic noise of the detection unit showed a 1/f noise characteristic and a sensitivity of 10 10 Am 2 at 100 Hz was showed by the developed system. To demonstrate the feasibility of the developed system, harmonics of Nickel nanowires was measured. The harmonics generation increased with the increasing amplitude of excitation field. It can be expected that an extremely sensitive characterization of MNP is possible using the developed system.

Journal of Telecommunication, Electronic and Computer Engineering, Jan 18, 2018

A high-homogeneity excitation coil with a resonant circuit for AC magnetometer is developed. A so... more A high-homogeneity excitation coil with a resonant circuit for AC magnetometer is developed. A solenoid coil is designed to produce a high-homogeneity and strong excitation field using a resonant frequency method. The solenoid coil is fabricated with a Litz wire to suppress the increase of AC resistance due to the skin and proximity effects in the highfrequency region. The Litz wire is composed of 60 strands of copper wires with 0.1-mm diameter. The resonant frequency method is applied to cancel the reactance component by connecting the excitation coil with a capacitor in a series configuration. To enable excitation of the magnetic field at multiple frequencies, a resonant circuit consists of multiple values of resonant capacitors is constructed. The fabricated excitation coil showed a high homogeneity of the magnetic field and was able to maintain a constant resonant current up to 32.5 kHz.

Engineering research express, Jun 1, 2022

In this study, we report a development of a benchtop induction-based AC magnetometer to realize a... more In this study, we report a development of a benchtop induction-based AC magnetometer to realize a simple, wideband, and sensitive AC magnetometer for bio-sensing applications and characterization of magnetic nanoparticles (MNPs). We investigate the inductance and parasitic capacitance of six different pickup coil geometries and compare their sensitivity and usable frequency range. In the pickup coil design, the number of turns and coil section separation are varied from 200 to 400 turns, and 1 to 4 sections, respectively. We find that the usable frequency range is greatly affected by the pickup coil’s inductance due to the self-resonance phenomena compared to their parasitic capacitance. A low noise instrument amplifier circuit (AD8429, Analog Devices, USA) was integrated and fabricated on a printed circuit board to amplify the weak signal from the pickup coil. We also implement a generalized Goertzel algorithm to achieve fast signal amplitude and phase extractions at a frequency. The developed magnetometer shows a sensitivity of 10−8 Am2/√Hz at 6 Hz and a frequency range of up to 158 kHz. Using the developed AC magnetometer, we demonstrate the viscosity effect on the frequency response of thermally blocked, single-core nanoparticles (SHP30, Ocean Nanotech, USA) in glycerol solutions. The excitation frequency is swept from 5 Hz to 158 kHz at a field amplitude of 0.55 mTpp within the acquisition time of 5 min (51 points). As a result, the viscosity change is confirmed by the peak shifting in the imaginary magnetization curve towards lower frequency values when the wt/V% of the glycerol solution is increased. The hydrodynamic size and the average anisotropy energy ratio σ are estimated to be 60.6 nm and 25, respectively, from the complex AC magnetization. It can be expected that the developed AC magnetometer can be a valuable tool in providing a fast and reliable assessment of MNPs for bio-sensing applications.

Surfaces and Interfaces, Jun 1, 2023

2018 IEEE International Magnetics Conference (INTERMAG), Apr 1, 2018

Advanced Science Letters, Nov 1, 2017

In the recent years, with the fast advancement in the fields associated with nanoscience and nano... more In the recent years, with the fast advancement in the fields associated with nanoscience and nanotechnology, metal nanowires, in specific have received enormous attention among researchers due to their fascinating properties and applications. In this study, the Young Modulus and failure behavior of Nickel (Ni) nanowires 7.04 nm in diameter with eight (8) different lengths (