Asfand Yar - Academia.edu (original) (raw)

Papers by Asfand Yar

2018 AIAA Aerospace Sciences Meeting, 2018

Ceramics International, 2021

Abstract Morphological modification in materials aids multi-channel electron access sites for eas... more Abstract Morphological modification in materials aids multi-channel electron access sites for easier electrolyte ion access for many electrochemical devices including energy storage devices. Controlled synthesis of such multichannel morphologies of metal oxides offers significant challenges. Herein, we report a template-assisted electrodeposition technique for the synthesis of Cu nanowires, which are transformed into either CuO nanotubes by controlled annealing or CuO hierarchical nanospikes using a simple hydroxyl ion impregnation technique and subsequent annealing. These materials are tested as electrodes in charge storage systems in 6 M KOH electrolyte in a three-electrode system; both electrodes have shown battery-type charge storage behaviour. Despite the chemical similarity between the two materials, the CuO nanospikes electrodes showed improved charge transport between electrode-electrolyte interface compared to the CuO nanotubes. With the cost-effectiveness, easy availability, and multi-channel morphology of CuO nanospikes along with the promising performance of the electrode in a three-electrode system, the present research offers future potential in developing low cost and high performing energy storage devices.

Key Engineering Materials, 2020

The advantages of palm kernel shell (PKS) as a renewable and sustainable material for activated c... more The advantages of palm kernel shell (PKS) as a renewable and sustainable material for activated carbon production have been explored for various applications such as water treatment, pollutant, pesticide, and heavy metal adsorption. However, the full promises of this material for energy storage devices have not been duly studied. In this research, PKS is physically activated and the effect of particle size on the physical characteristics of the activated char was investigated. Pellet (3 mm), granules (0.4 mm), and powder (0.0075 mm) are the sizes considered in the experiment. The surface morphology, surface area, porosity and functional group at different sized was analyzed. Finally, a suitable particle size was recommended for the electrode material of supercapacitor based on the physical characteristics of the activated carbon.

Journal of Alloys and Compounds, 2020

The oxygen-containing functional groups in graphene oxide (GO) impose considerable limitations in... more The oxygen-containing functional groups in graphene oxide (GO) impose considerable limitations in their applications requiring chemical inertness and electrical conductivity such as supercapacitive charge storage. Chemical reduction of GO has been frequently employed; however, processing of large volume of hazardous solvents impose severe environmental concerns. This article demonstrates the optical reduction of freeze dried GO into reduced GO (rGO) by a computer controlled laser engraver as a plug and operate device. The conversion of GO into rGO as a function of laser powers has been monitored by X-ray diffraction, X-ray photon electron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, Thermogravimetric analysis, and field emission scanning microscopy. The rGO thus produced has been evaluated for their charge storage capability in aqueous electrolytes. The best performing laboratory prototype demonstrated one of the best energy density of rGO electrodes in an aqueous electrolyte. The promising properties of the supercapacitors thereby developed as well as cost effectiveness and potential for large scale production engaging laser engraving process, the present work offers numerous potentials for deploying efficient and low cost supercapacitive devices.

Results in Physics, 2019

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Journal of Materials Research and Technology, 2019

Conversion of palm waste to activated carbon have attracted significant attention due to their li... more Conversion of palm waste to activated carbon have attracted significant attention due to their lignocellulose chemistry and abundance. In the past, several palm waste has been converted to activated carbon for various applications. The highly porous material is efficient for application in gas, heavy metals, and pesticide adsorption, water purification, and as the active material of electrochemical double layer capacitor. Due to variation in the preparatory conditions, there is no adequate comparison in the electrochemical properties of palm waste derived activated carbons. In this study, palm kernel shell (PKS), oil palm fiber (OPF), and empty fruit bunch (EFB) were used to produce activated carbon by one step physical carbonization and activation at 700 • C and 1 h hold time. A comparative analysis of the physiochemical characteristics of the activated carbon is presented. XRD results reflect the amorphous nature of all the samples and BET surface area of 823 m 2 /g, 700 m 2 /g, and 592 m 2 /g were recorded for EFB, PKS, and OPF, respectively.

International Journal of Hydrogen Energy, 2018

Please cite this article in press as: Mumtaz A, et al., Mutual effect of extrinsic defects and el... more Please cite this article in press as: Mumtaz A, et al., Mutual effect of extrinsic defects and electronic carbon traps of M-TiO 2 (M ¼ V, Co, Ni) nanorod arrays on photoexcited charge extraction of CdS for superior photoelectrochemical activity of hydrogen production, In

Journal of Physics: Conference Series, 2018

Polyaniline (PANI)-reduced graphene oxide (rGO) based transparent counter electrodes have been fa... more Polyaniline (PANI)-reduced graphene oxide (rGO) based transparent counter electrodes have been fabricated for dye sensitized solar cells as an alternative to the expensive platinum (Pt) counter electrodes. Here, the graphene oxide (GO) added during the polymerization of PANI will subsequently reduce to rGO. The concentration of graphene oxide (GO) was varied in PANI matrix to optimize the performance of dye solar cell (DSC). With 1% GO addition in PANI, 9.68% current density was increased, consequently, 13.9% photocurrent density was found to be increased as compared to pure PANI. Electrochemical impedance spectroscopy (EIS) disclosed that the incorporation of 1% GO in PANI caused the double-layer capacitance to increase by 10 times compared to pure PANI. This implies that graphene is capable of enhancing the specific surface area and catalytic capacity of PANI. Optical transparency of PANI-1% GO counter electrode was found to be ~67% between the wavelengths of 500 to 600 nm. Such transparency enables the construction of bifacial DSCs. Although the photo conversion efficiency (PCE) of DSC with PANI-1% GO counter electrode is still not comparable to the one with Pt counter electrode but it is sufficient to be considered as the replacement as it exhibits good photovoltaic performance and optical characteristics together with an exceptionally low cost material.

Journal of Physics: Conference Series, 2018

Supercapacitors are consider superior than batteries in terms of cycle life and power delivery wh... more Supercapacitors are consider superior than batteries in terms of cycle life and power delivery which make them more attractive in many applications. Commercially available supercapacitor mostly rely on carbon material which have low capacitance values as compared to nano or micro metal oxides structures. Among metal oxides, nickel oxides with different structures are widely under investigation, but still controlling over the structure is not addressed for supercapacitor application. In this study well controlled one dimensional nano structures were synthesized by using alumina template. Most importantly, full utilization of alumina template was carried out by optimizing growth time of the deposition of nickel wires in 1-D nano-channels of alumina. As prepared nickel nanowires were annealed in air and tested as supercapacitor electrode in potassium hydroxide electrolyte solution. Specific capacitance was calculated to be 380 F/g by cyclic voltammetry at scan rate of 2 mV/s.

AIP Conference Proceedings, 2016

Supercapacitors are highly attractive energy storage devices which are capable of delivering high... more Supercapacitors are highly attractive energy storage devices which are capable of delivering high power, with fast charging and long cycle life. Carbon based material rely on physical charging with less capacitance while metal oxide store charge by fast redox reaction with increased capacitance. Among metal oxide, copper oxide compounds are widely use in the form of nano and micro structures with no definite control over structure. In this work we utilized the well-controlled structure copper wires, originated from AAO template. Such well controlled structure offer better capacitance values due to easily excess of ions to the surface of wires. Performance of material was check in 3 M of potassium hydroxide (KOH). Specific capacitance (Cs) was calculated by using cyclic voltammetry (CV) and Charge discharge (CDC) test. The capacitance calculate on base on CV at 25 mV/s was 101.37 F/g while CDC showed the capacitance of 90 F/g at 2 A/g.

Chemical Engineering Journal, 2017

h i g h l i g h t s Nanowires of a composite, Mn 2 O 3-SnO 2 , are synthesized at 100 g scale. Th... more h i g h l i g h t s Nanowires of a composite, Mn 2 O 3-SnO 2 , are synthesized at 100 g scale. The composite nanowires showed beneficial properties of the constituents. They showed significantly high charge storability and cyclability than the constituents. The superior charge storage are attributed to lower characteristic resistances.

Electrochimica Acta, 2017

Critical influence of reduced graphene oxide mediated binding of M (M = Mg, Mn) with Co ions, che... more Critical influence of reduced graphene oxide mediated binding of M (M = Mg, Mn) with Co ions, chemical stability and charge storability enhancements of spinal-type hierarchical MCo 2 O 4 nanostructures

The Journal of Physical Chemistry C, 2017

55th AIAA Aerospace Sciences Meeting, 2017

Hydrogen production by splitting of water using solar means is a renewable alternative and is a n... more Hydrogen production by splitting of water using solar means is a renewable alternative and is a need of the hour. The generation of hydrogen is studied using nanostructured V2O5/TiO2 bilayer photoctatalyst synthesized by two different methods. The solution deposition followed by annealing and flame oxidized methods are applied to deposit the nanostructured V2O5 onto TiO2 nanorod arrays. These two methods are compared and studied using X-ray diffraction, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), electron energy loss spectrum and photoelectrochemical study. The morphological study provides the optimized surface area of the TiO2 nanorod arrays. It shows that 0.45 mL tetra butyl titanate at 180C shows the improved surface area. It also differentiates the 3D network as morphology of nanostructured V2O5/TiO2 bilayer photoctatalyst synthesized by flame oxidation method. Electron energy loss spectrum confirms the presence of respective elemental states of V2O5/Ti...

Journal of Magnetics, 2014

The electrical transport properties of YBCO single layers thin film have been investigated using ... more The electrical transport properties of YBCO single layers thin film have been investigated using different physical techniques. For the purpose, the physical properties are probed numerically with help of simulation modelling. The physical transport properties were also estimated with temperature and magnetic fields limits using thermally-activated flux flow model with some modifications. The result of present simulation modelling indicated that the magnitude of activation energy depends on temperature and magnetic field. The simulations revealed thickness dependent physical transport properties including electrical and magnetic properties of deposited YBCO single layers thin films. Furthermore, it shows the temperature dependence of the pinning energy. In the nutshell, the result can be used to improve the Superconducting Properties (T c) of the YBCO single layers thin films.

AIP Conference Proceedings, 2015

Nanowires of magnetic materials such as Iron, nickel, cobalt, and alloys of them are one of the m... more Nanowires of magnetic materials such as Iron, nickel, cobalt, and alloys of them are one of the most widely investigated structures because of their possible applications in high density magnetic recording media, sensor elements, and building blocks in biological transport systems. In this work, Iron nanowires have been prepared by electrodeposition technique using Anodized Aluminium Oxide (AAO) templates. The electrolyte used consisted of FeSO4.6H2O buffered with H3BO3 and acidized by dilute H2SO4. FESEM analysis shows that the asdeposited nanowires are parallel to one another and have high aspect ratio with a reasonably high pore-filing factor. To fabricate the working electrode, a thin film of copper (∼ 220 nm thick) was coated on back side of AAO template by e-beam evaporation system to create electrical contact with the external circuit. The TEM results show that electrodeposited nanowires have diameter around 100 nm and are polycrystalline in structure. Magnetic properties show the existence of anis...

The Pulse laser deposition (PLD) is a sole tool that is used to develop fine quality superconduct... more The Pulse laser deposition (PLD) is a sole tool that is used to develop fine quality superconducting (YBCO) epitaxial films. The description and devices application aspect of the PLD on high temperature superconducting epitaxial films have an important role in the field of superconductivity. In the present study, thin films fabrication by PLD, buffer layers and electrical properties have been probed numerically with computer simulations. The electrical transport properties are discussed in term of thermally-activated flux motion model. The present study concludes that the plume dynamics is important in fabricating high quality epitaxial films thus improving the superconducting electrical transport properties.

2014 5th International Conference on Intelligent and Advanced Systems (ICIAS), 2014

Piezoresistive effect is commonly used as transduction mechanism in microelectromechanical system... more Piezoresistive effect is commonly used as transduction mechanism in microelectromechanical systems (MEMS) and Wheatstone bridge as readout circuit. This paper presents modeling and simulation of two modes of vibration in the MEMS device through embedded piezoresistors which are arranged in Wheatstone bridge configuration, modeling is extended up to n branches for wide range of applications in MEMS. The comparative analysis of fully and half differential setups even with one variable resistor with balanced form of the two branch bridge is modeled as well as simulated using Multisim8. The sensitivity of the bridge in fully, half and with one variable resistor configuration is found to be 2 μV/mΩ, 1 μV/mΩ and 0.49 μV/mΩ respectively. It is found that fully differential set up is the most sensitive one. This output is amplifiable by using 1000 gain amplifier.

2018 AIAA Aerospace Sciences Meeting, 2018

Ceramics International, 2021

Abstract Morphological modification in materials aids multi-channel electron access sites for eas... more Abstract Morphological modification in materials aids multi-channel electron access sites for easier electrolyte ion access for many electrochemical devices including energy storage devices. Controlled synthesis of such multichannel morphologies of metal oxides offers significant challenges. Herein, we report a template-assisted electrodeposition technique for the synthesis of Cu nanowires, which are transformed into either CuO nanotubes by controlled annealing or CuO hierarchical nanospikes using a simple hydroxyl ion impregnation technique and subsequent annealing. These materials are tested as electrodes in charge storage systems in 6 M KOH electrolyte in a three-electrode system; both electrodes have shown battery-type charge storage behaviour. Despite the chemical similarity between the two materials, the CuO nanospikes electrodes showed improved charge transport between electrode-electrolyte interface compared to the CuO nanotubes. With the cost-effectiveness, easy availability, and multi-channel morphology of CuO nanospikes along with the promising performance of the electrode in a three-electrode system, the present research offers future potential in developing low cost and high performing energy storage devices.

Key Engineering Materials, 2020

The advantages of palm kernel shell (PKS) as a renewable and sustainable material for activated c... more The advantages of palm kernel shell (PKS) as a renewable and sustainable material for activated carbon production have been explored for various applications such as water treatment, pollutant, pesticide, and heavy metal adsorption. However, the full promises of this material for energy storage devices have not been duly studied. In this research, PKS is physically activated and the effect of particle size on the physical characteristics of the activated char was investigated. Pellet (3 mm), granules (0.4 mm), and powder (0.0075 mm) are the sizes considered in the experiment. The surface morphology, surface area, porosity and functional group at different sized was analyzed. Finally, a suitable particle size was recommended for the electrode material of supercapacitor based on the physical characteristics of the activated carbon.

Journal of Alloys and Compounds, 2020

The oxygen-containing functional groups in graphene oxide (GO) impose considerable limitations in... more The oxygen-containing functional groups in graphene oxide (GO) impose considerable limitations in their applications requiring chemical inertness and electrical conductivity such as supercapacitive charge storage. Chemical reduction of GO has been frequently employed; however, processing of large volume of hazardous solvents impose severe environmental concerns. This article demonstrates the optical reduction of freeze dried GO into reduced GO (rGO) by a computer controlled laser engraver as a plug and operate device. The conversion of GO into rGO as a function of laser powers has been monitored by X-ray diffraction, X-ray photon electron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, Thermogravimetric analysis, and field emission scanning microscopy. The rGO thus produced has been evaluated for their charge storage capability in aqueous electrolytes. The best performing laboratory prototype demonstrated one of the best energy density of rGO electrodes in an aqueous electrolyte. The promising properties of the supercapacitors thereby developed as well as cost effectiveness and potential for large scale production engaging laser engraving process, the present work offers numerous potentials for deploying efficient and low cost supercapacitive devices.

Results in Physics, 2019

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Journal of Materials Research and Technology, 2019

Conversion of palm waste to activated carbon have attracted significant attention due to their li... more Conversion of palm waste to activated carbon have attracted significant attention due to their lignocellulose chemistry and abundance. In the past, several palm waste has been converted to activated carbon for various applications. The highly porous material is efficient for application in gas, heavy metals, and pesticide adsorption, water purification, and as the active material of electrochemical double layer capacitor. Due to variation in the preparatory conditions, there is no adequate comparison in the electrochemical properties of palm waste derived activated carbons. In this study, palm kernel shell (PKS), oil palm fiber (OPF), and empty fruit bunch (EFB) were used to produce activated carbon by one step physical carbonization and activation at 700 • C and 1 h hold time. A comparative analysis of the physiochemical characteristics of the activated carbon is presented. XRD results reflect the amorphous nature of all the samples and BET surface area of 823 m 2 /g, 700 m 2 /g, and 592 m 2 /g were recorded for EFB, PKS, and OPF, respectively.

International Journal of Hydrogen Energy, 2018

Please cite this article in press as: Mumtaz A, et al., Mutual effect of extrinsic defects and el... more Please cite this article in press as: Mumtaz A, et al., Mutual effect of extrinsic defects and electronic carbon traps of M-TiO 2 (M ¼ V, Co, Ni) nanorod arrays on photoexcited charge extraction of CdS for superior photoelectrochemical activity of hydrogen production, In

Journal of Physics: Conference Series, 2018

Polyaniline (PANI)-reduced graphene oxide (rGO) based transparent counter electrodes have been fa... more Polyaniline (PANI)-reduced graphene oxide (rGO) based transparent counter electrodes have been fabricated for dye sensitized solar cells as an alternative to the expensive platinum (Pt) counter electrodes. Here, the graphene oxide (GO) added during the polymerization of PANI will subsequently reduce to rGO. The concentration of graphene oxide (GO) was varied in PANI matrix to optimize the performance of dye solar cell (DSC). With 1% GO addition in PANI, 9.68% current density was increased, consequently, 13.9% photocurrent density was found to be increased as compared to pure PANI. Electrochemical impedance spectroscopy (EIS) disclosed that the incorporation of 1% GO in PANI caused the double-layer capacitance to increase by 10 times compared to pure PANI. This implies that graphene is capable of enhancing the specific surface area and catalytic capacity of PANI. Optical transparency of PANI-1% GO counter electrode was found to be ~67% between the wavelengths of 500 to 600 nm. Such transparency enables the construction of bifacial DSCs. Although the photo conversion efficiency (PCE) of DSC with PANI-1% GO counter electrode is still not comparable to the one with Pt counter electrode but it is sufficient to be considered as the replacement as it exhibits good photovoltaic performance and optical characteristics together with an exceptionally low cost material.

Journal of Physics: Conference Series, 2018

Supercapacitors are consider superior than batteries in terms of cycle life and power delivery wh... more Supercapacitors are consider superior than batteries in terms of cycle life and power delivery which make them more attractive in many applications. Commercially available supercapacitor mostly rely on carbon material which have low capacitance values as compared to nano or micro metal oxides structures. Among metal oxides, nickel oxides with different structures are widely under investigation, but still controlling over the structure is not addressed for supercapacitor application. In this study well controlled one dimensional nano structures were synthesized by using alumina template. Most importantly, full utilization of alumina template was carried out by optimizing growth time of the deposition of nickel wires in 1-D nano-channels of alumina. As prepared nickel nanowires were annealed in air and tested as supercapacitor electrode in potassium hydroxide electrolyte solution. Specific capacitance was calculated to be 380 F/g by cyclic voltammetry at scan rate of 2 mV/s.

AIP Conference Proceedings, 2016

Supercapacitors are highly attractive energy storage devices which are capable of delivering high... more Supercapacitors are highly attractive energy storage devices which are capable of delivering high power, with fast charging and long cycle life. Carbon based material rely on physical charging with less capacitance while metal oxide store charge by fast redox reaction with increased capacitance. Among metal oxide, copper oxide compounds are widely use in the form of nano and micro structures with no definite control over structure. In this work we utilized the well-controlled structure copper wires, originated from AAO template. Such well controlled structure offer better capacitance values due to easily excess of ions to the surface of wires. Performance of material was check in 3 M of potassium hydroxide (KOH). Specific capacitance (Cs) was calculated by using cyclic voltammetry (CV) and Charge discharge (CDC) test. The capacitance calculate on base on CV at 25 mV/s was 101.37 F/g while CDC showed the capacitance of 90 F/g at 2 A/g.

Chemical Engineering Journal, 2017

h i g h l i g h t s Nanowires of a composite, Mn 2 O 3-SnO 2 , are synthesized at 100 g scale. Th... more h i g h l i g h t s Nanowires of a composite, Mn 2 O 3-SnO 2 , are synthesized at 100 g scale. The composite nanowires showed beneficial properties of the constituents. They showed significantly high charge storability and cyclability than the constituents. The superior charge storage are attributed to lower characteristic resistances.

Electrochimica Acta, 2017

Critical influence of reduced graphene oxide mediated binding of M (M = Mg, Mn) with Co ions, che... more Critical influence of reduced graphene oxide mediated binding of M (M = Mg, Mn) with Co ions, chemical stability and charge storability enhancements of spinal-type hierarchical MCo 2 O 4 nanostructures

The Journal of Physical Chemistry C, 2017

55th AIAA Aerospace Sciences Meeting, 2017

Hydrogen production by splitting of water using solar means is a renewable alternative and is a n... more Hydrogen production by splitting of water using solar means is a renewable alternative and is a need of the hour. The generation of hydrogen is studied using nanostructured V2O5/TiO2 bilayer photoctatalyst synthesized by two different methods. The solution deposition followed by annealing and flame oxidized methods are applied to deposit the nanostructured V2O5 onto TiO2 nanorod arrays. These two methods are compared and studied using X-ray diffraction, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), electron energy loss spectrum and photoelectrochemical study. The morphological study provides the optimized surface area of the TiO2 nanorod arrays. It shows that 0.45 mL tetra butyl titanate at 180C shows the improved surface area. It also differentiates the 3D network as morphology of nanostructured V2O5/TiO2 bilayer photoctatalyst synthesized by flame oxidation method. Electron energy loss spectrum confirms the presence of respective elemental states of V2O5/Ti...

Journal of Magnetics, 2014

The electrical transport properties of YBCO single layers thin film have been investigated using ... more The electrical transport properties of YBCO single layers thin film have been investigated using different physical techniques. For the purpose, the physical properties are probed numerically with help of simulation modelling. The physical transport properties were also estimated with temperature and magnetic fields limits using thermally-activated flux flow model with some modifications. The result of present simulation modelling indicated that the magnitude of activation energy depends on temperature and magnetic field. The simulations revealed thickness dependent physical transport properties including electrical and magnetic properties of deposited YBCO single layers thin films. Furthermore, it shows the temperature dependence of the pinning energy. In the nutshell, the result can be used to improve the Superconducting Properties (T c) of the YBCO single layers thin films.

AIP Conference Proceedings, 2015

Nanowires of magnetic materials such as Iron, nickel, cobalt, and alloys of them are one of the m... more Nanowires of magnetic materials such as Iron, nickel, cobalt, and alloys of them are one of the most widely investigated structures because of their possible applications in high density magnetic recording media, sensor elements, and building blocks in biological transport systems. In this work, Iron nanowires have been prepared by electrodeposition technique using Anodized Aluminium Oxide (AAO) templates. The electrolyte used consisted of FeSO4.6H2O buffered with H3BO3 and acidized by dilute H2SO4. FESEM analysis shows that the asdeposited nanowires are parallel to one another and have high aspect ratio with a reasonably high pore-filing factor. To fabricate the working electrode, a thin film of copper (∼ 220 nm thick) was coated on back side of AAO template by e-beam evaporation system to create electrical contact with the external circuit. The TEM results show that electrodeposited nanowires have diameter around 100 nm and are polycrystalline in structure. Magnetic properties show the existence of anis...

The Pulse laser deposition (PLD) is a sole tool that is used to develop fine quality superconduct... more The Pulse laser deposition (PLD) is a sole tool that is used to develop fine quality superconducting (YBCO) epitaxial films. The description and devices application aspect of the PLD on high temperature superconducting epitaxial films have an important role in the field of superconductivity. In the present study, thin films fabrication by PLD, buffer layers and electrical properties have been probed numerically with computer simulations. The electrical transport properties are discussed in term of thermally-activated flux motion model. The present study concludes that the plume dynamics is important in fabricating high quality epitaxial films thus improving the superconducting electrical transport properties.

2014 5th International Conference on Intelligent and Advanced Systems (ICIAS), 2014

Piezoresistive effect is commonly used as transduction mechanism in microelectromechanical system... more Piezoresistive effect is commonly used as transduction mechanism in microelectromechanical systems (MEMS) and Wheatstone bridge as readout circuit. This paper presents modeling and simulation of two modes of vibration in the MEMS device through embedded piezoresistors which are arranged in Wheatstone bridge configuration, modeling is extended up to n branches for wide range of applications in MEMS. The comparative analysis of fully and half differential setups even with one variable resistor with balanced form of the two branch bridge is modeled as well as simulated using Multisim8. The sensitivity of the bridge in fully, half and with one variable resistor configuration is found to be 2 μV/mΩ, 1 μV/mΩ and 0.49 μV/mΩ respectively. It is found that fully differential set up is the most sensitive one. This output is amplifiable by using 1000 gain amplifier.