International Journal for Simulation and Multidisciplinary Design Optimization, 2021
The demand for flexible and wearable sensors is increasing day by day due to varied applications ... more The demand for flexible and wearable sensors is increasing day by day due to varied applications in the biomedical field. Especially highly sensitive sensors are required for the detection of the low signal from the body. It is important to develop a pressure sensor that can convert the maximum input signal into the electrical output. In this paper, the design and performance of graphene piezoresistive pressure sensors have been investigated by zig–zag piezoresistors on the square diaphragm. On the applied pressure, deformation is sensed by the piezoresistors above the diaphragm. Finite element analysis is carried out to investigate the effect of zig–zag piezoresistors on the square diaphragm. Simulated results for the optimized design are obtained for an operating range of 0–100 psi for pressure sensitivity.
AbstractAs the requirement of wireless communication services are growing, the demand of frequenc... more AbstractAs the requirement of wireless communication services are growing, the demand of frequency resource is increasing. Cognitive radio proposed to solve the frequency scarcity started two decades before is now the key tool. The band width becomes expensive due to shortage of frequencies. Therefore to use the spectrum effectively, we need to identify whether the spectrum is occupied or not. Energy detection, Feature detection and Matched Filter detection are methods used for spectrum sensing. In this paper we have use Discrete Wavelet Packet Decomposition based Energy Detection (DWPDED) for sense the unused spectrum band in the RF spectrum. Simulation outcomes revels better results and fast sensing than the conventional method.
A TWO-DAY CONFERENCE ON FLEXIBLE ELECTRONICS FOR ELECTRIC VEHICLES
Demand of MEMS sensor is increasing due to its applicability in various fields such as in automob... more Demand of MEMS sensor is increasing due to its applicability in various fields such as in automobile and industrial applications. Save driving is very necessary which can be properly accomplish by usage of flexible MEMS devices which can monitor different parameters such as tyre pressure, speed etc. Tyre pressure monitoring system consists of flexible MEMS pressure sensor, which provide low power consumption and temperature compatibility by proper selection of the sensor material. In this paper, modelling of graphene based flexible piezoresistive pressure sensor has been carried out for monitoring of the tyre pressure. Graphene is used as a substrate material, which makes the flexible device that can be implanted easily in the tyre. Graphene is also used as the sensing material for piezoresistors. Results indicate that sensitivity of 0.63 mV/kPa is achieved at room temperature.
MEMS piezoresistive pressure sensors are most widely explored for various applications such as in... more MEMS piezoresistive pressure sensors are most widely explored for various applications such as industrial, automotive and medical field. Each application covers a wide operating range from very low pressure to the higher pressure. In this paper a novel structure is designed by introducing the local stiffness in the diaphragm membrane for low pressure measurement. Rod beams at the diaphragm with combination of graphene piezoresistors, improves overall performance of the pressure sensor in terms of sensitivity. At higher temperature and higher pressure, a noticeable sensitivity is achieved which is compared to the previous design of graphene pressure sensor without rod beam structure. At room temperature (25 °C), sensitivity of pressure sensor with rod beam structure is 6.28 mV/psi. At 30 °C, the sensitivity is 58% higher than sensitivity of pressure sensor without rod beam structure for low-pressure specific range.
IOP Conference Series: Materials Science and Engineering
In this paper, stress and eigen frequencies are analyzed through prediction of microcantilever mo... more In this paper, stress and eigen frequencies are analyzed through prediction of microcantilever model using design of experiment approach. The important factors affecting displacement sensitivity, stress and eigen frequencies were identified such as geometrical dimensions of microcantilever (length, breadth and thickness), modulus of elasticity of materials, applied force. Based on the selection of factors and levels, experiments were designed using L9 orthogonal array. The designed experiments were simulated with finite element method in COMSOL Multiphysics software. Further, optimum values of dimensions of microcantilever and material property are used for stress and eigen frequencies analysis. The evaluated frequencies under eigen frequency analysis revealed that designed and simulated Gallium Arsenide (GaAs) microcantilever is prone to vibrate at these frequencies, whereas stress analysis illustrates the response of structure and material properties towards reliability.
Abstract Resin based dental composites are quite popular for tooth restoration. In this article, ... more Abstract Resin based dental composites are quite popular for tooth restoration. In this article, BisGMA and TEGDMA were mixed to make resin matrix. For photo-polymerization, Camphorquinone was used and DMAEA was used as accelerator. Silica was employed as filler in different %wt (0%, 3%, 6% and 9%). The samples were tested for compressive strength and void content. This study reveals experimentally that introduction of silica in dental resin significantly increasing compressive strength and void content of resin based dental composite. Maximum compressive strength of 150.47 MPa was found at 9%wt of silica and minimum void content of 0.89% were found at 3%wt of silica as filler in dental composite.
This review article compiles the characteristics of resin based dental composites and an effort i... more This review article compiles the characteristics of resin based dental composites and an effort is made to point out their future perspectives. Recent research studies along with few earlier articles were studied to compile the synthesis schemes of commonly used monomers, their characteristics in terms of their physical, mechanical and polymerization process with selectivity towards the input parameters of polymerization process. This review covers surface modification processes of various filler particles using silanes, wear behaviour, antimicrobial behaviour along with its testing procedures to develop the fundamental knowledge of various characteristics of resin based composites. In the end of this review, possible areas of further interests are pointed out on the basis of literature review on resin based dental materials.
Journal of the Mechanical Behavior of Biomedical Materials
This paper investigates the effect of %wt composition of BisGMA/TEGDMA, stirring time, bench time... more This paper investigates the effect of %wt composition of BisGMA/TEGDMA, stirring time, bench time, curing time and filler loading on polymerization shrinkage and micro-hardness of resin based dental composites. The investigation was carried out in two stages. In first stage, samples were prepared with different %wt composition of BisGMA/TEGDMA, stirring time, bench time, and curing time to access the effect of different input parameters for minimum polymerization shrinkage and maximum micro-hardness using Taguchi methodology. Selecting optimum values of input factors from first stage, second stage optimization was performed to investigate the effects of different filler loading on different %wt composition of BisGMA/TEGDMA using full factorial design. Prediction model was developed using Design Expert software and analysis of effect of input parameters on output responses were carried out using 3D surface plots. ANOVA were performed to check the significance of prediction model. In first stage, optimum stirring time, bench time and curing time were found to be 4 h, 50 min and 30 s, respectively. In second stage, optimum polymerization shrinkage and micro-hardness of 3.54% and 310 Hv were predicted at 22.89% of TEGDMA content and 20% filler loading. Taguchi methodology and full factorial design were successfully implemented to access the effect of multi-input parameters on responses for resin based dental composites.
Single wall carbon nanotubes (SWNT) are functionalized with poly(vinyl alcohol) (PVA). The functi... more Single wall carbon nanotubes (SWNT) are functionalized with poly(vinyl alcohol) (PVA). The functionalized nanotubes are homogeneously dispersed in a PVA solution. Nanocomposite films with low SWNT content (0.1 to 1%) are produced by the wet-casting method. X-ray diffraction shows that the PVA crystallinity was not affected by the presence of the SWNT. The improvement in tensile modulus and strength at such low reinforcement loadings is indicative of good interfacial bonding between the functionalized nanotubes and the polymer matrix.
MEMS pressure sensor has shown a remarkable change in revenue collection during the year 2018. Du... more MEMS pressure sensor has shown a remarkable change in revenue collection during the year 2018. Due to recent growth in smart microsystem technology for automation systems, demand has grown substantially for sensors. High sensitivity, flexibility, miniaturization and bulk production are some of the key factors of a pressure sensor in achieving new heights in the MEMS market. In this paper, Graphene piezo resistive material has been analysed for pressure sensing elements and compared with Polysilicon in terms of sensitivity and sensor performance degradation at different temperature. MEMS pressure sensors using Polysilicon and Graphene piezo resistive materials were simulated on silicon (100) substrate by COMSOL Multiphysics 5.3a version. The simulation result shows that at room temperature polysilicon pressure sensor performs well with pressure sensitivity of 3.81 mV/psi as well as it is found that graphene pressure sensor also shows better results at room temperature showing a pressure sensitivity of 3.98 mV/psi. As on frequently increasing the temperature it is noticed that polysilicon pressure sensitivity degrades with a factor of 0.64 mV/psi. However, graphene pressure sensor shows very less variation in sensitivity at higher temperature. Although it shows a small increment of 0.02 mV/psi in the pressure sensitivity. This analysis opens the path to utilise the graphene pressure sensor at high temperature.
International Journal for Simulation and Multidisciplinary Design Optimization, 2021
The demand for flexible and wearable sensors is increasing day by day due to varied applications ... more The demand for flexible and wearable sensors is increasing day by day due to varied applications in the biomedical field. Especially highly sensitive sensors are required for the detection of the low signal from the body. It is important to develop a pressure sensor that can convert the maximum input signal into the electrical output. In this paper, the design and performance of graphene piezoresistive pressure sensors have been investigated by zig–zag piezoresistors on the square diaphragm. On the applied pressure, deformation is sensed by the piezoresistors above the diaphragm. Finite element analysis is carried out to investigate the effect of zig–zag piezoresistors on the square diaphragm. Simulated results for the optimized design are obtained for an operating range of 0–100 psi for pressure sensitivity.
AbstractAs the requirement of wireless communication services are growing, the demand of frequenc... more AbstractAs the requirement of wireless communication services are growing, the demand of frequency resource is increasing. Cognitive radio proposed to solve the frequency scarcity started two decades before is now the key tool. The band width becomes expensive due to shortage of frequencies. Therefore to use the spectrum effectively, we need to identify whether the spectrum is occupied or not. Energy detection, Feature detection and Matched Filter detection are methods used for spectrum sensing. In this paper we have use Discrete Wavelet Packet Decomposition based Energy Detection (DWPDED) for sense the unused spectrum band in the RF spectrum. Simulation outcomes revels better results and fast sensing than the conventional method.
A TWO-DAY CONFERENCE ON FLEXIBLE ELECTRONICS FOR ELECTRIC VEHICLES
Demand of MEMS sensor is increasing due to its applicability in various fields such as in automob... more Demand of MEMS sensor is increasing due to its applicability in various fields such as in automobile and industrial applications. Save driving is very necessary which can be properly accomplish by usage of flexible MEMS devices which can monitor different parameters such as tyre pressure, speed etc. Tyre pressure monitoring system consists of flexible MEMS pressure sensor, which provide low power consumption and temperature compatibility by proper selection of the sensor material. In this paper, modelling of graphene based flexible piezoresistive pressure sensor has been carried out for monitoring of the tyre pressure. Graphene is used as a substrate material, which makes the flexible device that can be implanted easily in the tyre. Graphene is also used as the sensing material for piezoresistors. Results indicate that sensitivity of 0.63 mV/kPa is achieved at room temperature.
MEMS piezoresistive pressure sensors are most widely explored for various applications such as in... more MEMS piezoresistive pressure sensors are most widely explored for various applications such as industrial, automotive and medical field. Each application covers a wide operating range from very low pressure to the higher pressure. In this paper a novel structure is designed by introducing the local stiffness in the diaphragm membrane for low pressure measurement. Rod beams at the diaphragm with combination of graphene piezoresistors, improves overall performance of the pressure sensor in terms of sensitivity. At higher temperature and higher pressure, a noticeable sensitivity is achieved which is compared to the previous design of graphene pressure sensor without rod beam structure. At room temperature (25 °C), sensitivity of pressure sensor with rod beam structure is 6.28 mV/psi. At 30 °C, the sensitivity is 58% higher than sensitivity of pressure sensor without rod beam structure for low-pressure specific range.
IOP Conference Series: Materials Science and Engineering
In this paper, stress and eigen frequencies are analyzed through prediction of microcantilever mo... more In this paper, stress and eigen frequencies are analyzed through prediction of microcantilever model using design of experiment approach. The important factors affecting displacement sensitivity, stress and eigen frequencies were identified such as geometrical dimensions of microcantilever (length, breadth and thickness), modulus of elasticity of materials, applied force. Based on the selection of factors and levels, experiments were designed using L9 orthogonal array. The designed experiments were simulated with finite element method in COMSOL Multiphysics software. Further, optimum values of dimensions of microcantilever and material property are used for stress and eigen frequencies analysis. The evaluated frequencies under eigen frequency analysis revealed that designed and simulated Gallium Arsenide (GaAs) microcantilever is prone to vibrate at these frequencies, whereas stress analysis illustrates the response of structure and material properties towards reliability.
Abstract Resin based dental composites are quite popular for tooth restoration. In this article, ... more Abstract Resin based dental composites are quite popular for tooth restoration. In this article, BisGMA and TEGDMA were mixed to make resin matrix. For photo-polymerization, Camphorquinone was used and DMAEA was used as accelerator. Silica was employed as filler in different %wt (0%, 3%, 6% and 9%). The samples were tested for compressive strength and void content. This study reveals experimentally that introduction of silica in dental resin significantly increasing compressive strength and void content of resin based dental composite. Maximum compressive strength of 150.47 MPa was found at 9%wt of silica and minimum void content of 0.89% were found at 3%wt of silica as filler in dental composite.
This review article compiles the characteristics of resin based dental composites and an effort i... more This review article compiles the characteristics of resin based dental composites and an effort is made to point out their future perspectives. Recent research studies along with few earlier articles were studied to compile the synthesis schemes of commonly used monomers, their characteristics in terms of their physical, mechanical and polymerization process with selectivity towards the input parameters of polymerization process. This review covers surface modification processes of various filler particles using silanes, wear behaviour, antimicrobial behaviour along with its testing procedures to develop the fundamental knowledge of various characteristics of resin based composites. In the end of this review, possible areas of further interests are pointed out on the basis of literature review on resin based dental materials.
Journal of the Mechanical Behavior of Biomedical Materials
This paper investigates the effect of %wt composition of BisGMA/TEGDMA, stirring time, bench time... more This paper investigates the effect of %wt composition of BisGMA/TEGDMA, stirring time, bench time, curing time and filler loading on polymerization shrinkage and micro-hardness of resin based dental composites. The investigation was carried out in two stages. In first stage, samples were prepared with different %wt composition of BisGMA/TEGDMA, stirring time, bench time, and curing time to access the effect of different input parameters for minimum polymerization shrinkage and maximum micro-hardness using Taguchi methodology. Selecting optimum values of input factors from first stage, second stage optimization was performed to investigate the effects of different filler loading on different %wt composition of BisGMA/TEGDMA using full factorial design. Prediction model was developed using Design Expert software and analysis of effect of input parameters on output responses were carried out using 3D surface plots. ANOVA were performed to check the significance of prediction model. In first stage, optimum stirring time, bench time and curing time were found to be 4 h, 50 min and 30 s, respectively. In second stage, optimum polymerization shrinkage and micro-hardness of 3.54% and 310 Hv were predicted at 22.89% of TEGDMA content and 20% filler loading. Taguchi methodology and full factorial design were successfully implemented to access the effect of multi-input parameters on responses for resin based dental composites.
Single wall carbon nanotubes (SWNT) are functionalized with poly(vinyl alcohol) (PVA). The functi... more Single wall carbon nanotubes (SWNT) are functionalized with poly(vinyl alcohol) (PVA). The functionalized nanotubes are homogeneously dispersed in a PVA solution. Nanocomposite films with low SWNT content (0.1 to 1%) are produced by the wet-casting method. X-ray diffraction shows that the PVA crystallinity was not affected by the presence of the SWNT. The improvement in tensile modulus and strength at such low reinforcement loadings is indicative of good interfacial bonding between the functionalized nanotubes and the polymer matrix.
MEMS pressure sensor has shown a remarkable change in revenue collection during the year 2018. Du... more MEMS pressure sensor has shown a remarkable change in revenue collection during the year 2018. Due to recent growth in smart microsystem technology for automation systems, demand has grown substantially for sensors. High sensitivity, flexibility, miniaturization and bulk production are some of the key factors of a pressure sensor in achieving new heights in the MEMS market. In this paper, Graphene piezo resistive material has been analysed for pressure sensing elements and compared with Polysilicon in terms of sensitivity and sensor performance degradation at different temperature. MEMS pressure sensors using Polysilicon and Graphene piezo resistive materials were simulated on silicon (100) substrate by COMSOL Multiphysics 5.3a version. The simulation result shows that at room temperature polysilicon pressure sensor performs well with pressure sensitivity of 3.81 mV/psi as well as it is found that graphene pressure sensor also shows better results at room temperature showing a pressure sensitivity of 3.98 mV/psi. As on frequently increasing the temperature it is noticed that polysilicon pressure sensitivity degrades with a factor of 0.64 mV/psi. However, graphene pressure sensor shows very less variation in sensitivity at higher temperature. Although it shows a small increment of 0.02 mV/psi in the pressure sensitivity. This analysis opens the path to utilise the graphene pressure sensor at high temperature.
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