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1 – 10 of 104Supriya Yadav, Kulwant Singh, Anmol Gupta, Mahesh Kumar, Niti Nipun Sharma and Jamil Akhtar
The purpose of this paper is to predict a suitable paper substrate which has high capillary pressure with the tendency of subsequent fluid wrenching in onward direction for the…
Abstract
Purpose
The purpose of this paper is to predict a suitable paper substrate which has high capillary pressure with the tendency of subsequent fluid wrenching in onward direction for the fabrication of microfluidics device application.
Design/methodology/approach
The experiment has been done on the WhatmanTM grade 1, WhatmanTM chromatography and nitrocellulose paper samples which are made by GE Healthcare Life Sciences. The structural characterization of paper samples for surface properties has been done by scanning electron microscope and ImageJ software. Identification of functional groups on the surface of samples has been done by Fourier transform infrared analysis. A finite elemental analysis has also been performed by using the “Multiphase Flow in Porous Media” module of the COMSOL Multiphysics tool which combines Darcy’s law and Phase Transport in Porous Media interface.
Findings
Experimentally, it has been concluded that the paper substrate for flexible microfluidic device application must have large number of internal (intra- and interfiber) pores with fewer void spaces (external pores) that have high capillary pressure to propel the fluid in onward direction with narrow paper fiber channel.
Originality/value
Surface structure has a dynamic impact in paper substrate utilization in multiple applications such as paper manufacturing, printing process and microfluidics applications.
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Shashi Kumar, Pradeep Kumar Rathore, Brishbhan Singh Panwar and Jamil Akhtar
This paper aims to describe the fabrication and characterization of current mirror-integrated microelectromechanical systems (MEMS)-based pressure sensor.
Abstract
Purpose
This paper aims to describe the fabrication and characterization of current mirror-integrated microelectromechanical systems (MEMS)-based pressure sensor.
Design/methodology/approach
The integrated pressure-sensing structure consists of three identical 100-µm long and 500-µm wide n-channel MOSFETs connected in a resistive loaded current mirror configuration. The input transistor of the mirror acts as a constant current source MOSFET and the output transistors are the stress sensing MOSFETs embedded near the fixed edge and at the center of a square silicon diaphragm to sense tensile and compressive stresses, respectively, developed under applied pressure. The current mirror circuit was fabricated using standard polysilicon gate complementary metal oxide semiconductor (CMOS) technology on the front side of the silicon wafer and the flexible pressure sensing square silicon diaphragm, with a length of 1,050 µm and width of 88 µm, was formed by bulk micromachining process using tetramethylammonium hydroxide solution on the backside of the wafer. The pressure is monitored by the acquisition of drain voltages of the pressure sensing MOSFETs placed near the fixed edge and at the center of the diaphragm.
Findings
The current mirror-integrated pressure sensor was successfully fabricated and tested using in-house developed pressure measurement system. The pressure sensitivity of the tested sensor was found to be approximately 0.3 mV/psi (or 44.6 mV/MPa) for pressure range of 0 to 100 psi. In addition, the pressure sensor was also simulated using Intellisuite MEMS Software and simulated pressure sensitivity of the sensor was found to be approximately 53.6 mV/MPa. The simulated and measured pressure sensitivities of the pressure sensor are in close agreement.
Originality/value
The work reported in this paper validates the use of MOSFETs connected in current mirror configuration for the measurement of tensile and compressive stresses developed in a silicon diaphragm under applied pressure. This current mirror readout circuitry integrated with MEMS pressure-sensing structure is new and fully compatible to standard CMOS processes and has a promising application in the development CMOS-MEMS-integrated smart sensors.
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Shashi Kumar, Gaddiella Diengdoh Ropmay, Pradeep Kumar Rathore, Peesapati Rangababu and Jamil Akhtar
This paper aims to describe the fabrication, packaging and testing of a resistive loaded p-channel metal-oxide-semiconductor field-effect transistor-based (MOSFET-based) current…
Abstract
Purpose
This paper aims to describe the fabrication, packaging and testing of a resistive loaded p-channel metal-oxide-semiconductor field-effect transistor-based (MOSFET-based) current mirror-integrated pressure transducer.
Design/methodology/approach
Using the concept of piezoresistive effect in a MOSFET, three identical p-channel MOSFETs connected in current mirror configuration have been designed and fabricated using the standard polysilicon gate process and microelectromechanical system (MEMS) techniques for pressure sensing application. The channel length and width of the p-channel MOSFETs are 100 µm and 500 µm, respectively. The MOSFET M1 of the current mirror is the reference transistor that acts as the constant current source. MOSFETs M2 and M3 are the pressure-sensing transistors embedded on the diaphragm near the mid of fixed edge and at the center of the square diaphragm, respectively, to experience both the tensile and compressive stress developed due to externally applied input pressure. A flexible square diaphragm having a length of approximately 1,000 µm and thickness of 50 µm has been realized using deep-reactive ion etching of silicon on the backside of the wafer. Then, the fabricated sensor chip has been diced and mounted on a TO8 header for the testing with pressure.
Findings
The experimental result of the pressure sensor chip shows a sensitivity of approximately 0.2162 mV/psi (31.35 mV/MPa) for an input pressure of 0-100 psi. The output response shows a good linearity and very low-pressure hysteresis. In addition, the pressure-sensing structure has been simulated using the parameters of the fabricated pressure sensor and from the simulation result a pressure sensitivity of approximately 0.2283 mV/psi (33.11 mV/MPa) has been observed for input pressure ranging from 0 to 100 psi with a step size of 10 psi. The simulated and experimentally tested pressure sensitivities of the pressure sensor are in close agreement with each other.
Originality/value
This current mirror readout circuit-based MEMS pressure sensor is new and fully compatible to standard CMOS processes and has a promising application in the development CMOS-MEMS-integrated smart sensors.
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Pradeep Kumar Rathore, Brishbhan Singh Panwar and Jamil Akhtar
The present paper aims to propose a basic current mirror-sensing circuit as an alternative to the traditional Wheatstone bridge circuit for the design and development of…
Abstract
Purpose
The present paper aims to propose a basic current mirror-sensing circuit as an alternative to the traditional Wheatstone bridge circuit for the design and development of high-sensitivity complementary metal oxide semiconductor (CMOS)–microelectromechanical systems (MEMS)-integrated pressure sensors.
Design/methodology/approach
This paper investigates a novel current mirror-sensing-based CMOS–MEMS-integrated pressure-sensing structure based on the piezoresistive effect in metal oxide field effect transistor (MOSFET). A resistive loaded n-channel MOSFET-based current mirror pressure-sensing circuitry has been designed using 5-μm CMOS technology. The pressure-sensing structure consists of three identical 10-μm-long and 50-μm-wide n-channel MOSFETs connected in current mirror configuration, with its input transistor as a reference MOSFET and output transistors are the pressure-sensing MOSFETs embedded at the centre and near the fixed edge of a silicon diaphragm measuring 100 × 100 × 2.5 μm. This arrangement of MOSFETs enables the sensor to sense tensile and compressive stresses, developed in the diaphragm under externally applied pressure, with respect to the input reference transistor of the mirror circuit. An analytical model describing the complete behaviour of the integrated pressure sensor has been described. The simulation results of the pressure sensor show high pressure sensitivity and a good agreement with the theoretical model has been observed. A five mask level process flow for the fabrication of the current mirror-sensing-based pressure sensor has also been described. An n-channel MOSFET with aluminium gate was fabricated to verify the fabrication process and obtain its electrical characteristics using process and device simulation software. In addition, an aluminium gate metal-oxide semiconductor (MOS) capacitor was fabricated on a two-inch p-type silicon wafer and its CV characteristic curve was also measured experimentally. Finally, the paper presents a comparative study between the current mirror pressure-sensing circuit with the traditional Wheatstone bridge.
Findings
The simulated sensitivities of the pressure-sensing MOSFETs of the current mirror-integrated pressure sensor have been found to be approximately 375 and 410 mV/MPa with respect to the reference transistor, and approximately 785 mV/MPa with respect to each other. The highest pressure sensitivities of a quarter, half and full Wheatstone bridge circuits were found to be approximately 183, 366 and 738 mV/MPa, respectively. These results clearly show that the current mirror pressure-sensing circuit is comparable and better than the traditional Wheatstone bridge circuits.
Originality/value
The concept of using a basic current mirror circuit for sensing tensile and compressive stresses developed in micro-mechanical structures is new, fully compatible to standard CMOS processes and has a promising application in the development of miniaturized integrated micro-sensors and sensor arrays for automobile, medical and industrial applications.
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Pradeep Kumar Rathore and Jamil Akhtar
The purpose of this paper is to describe the fabrication of a miniaturized membrane type double cavity vacuum‐sealed micro sensor for absolute pressure using front‐side lateral…
Abstract
Purpose
The purpose of this paper is to describe the fabrication of a miniaturized membrane type double cavity vacuum‐sealed micro sensor for absolute pressure using front‐side lateral etching technology.
Design/methodology/approach
Potassium hydroxide‐based anisotropic etching of single crystal silicon is used to realize the cavities under the membrane type diaphragms through channels on the sides. The diaphragms consist of composite layers of plasma‐enhanced chemical vapour deposition (PECVD) of silicon nitride and silicon dioxide. PECVD of silicon dioxide is done for sealing the channels and the cavity in vacuum. Boron thermal diffusion in low‐pressure chemical vapour deposition of polysilicon layer over the membrane is done for realizing resistors. The fabricated device uses Wheatstone half bridge circuit to read the variation of resistance with respect to an applied pressure.
Findings
A double cavity vacuum‐sealed absolute pressure micro sensor has been fabricated successfully using front‐side lateral etching technology and has been measured for pressure range of 0‐0.45 MPa. The measured pressure sensitivity of two pressure sensors is 9.28 and 10.44 mV/MPa.
Originality/value
The paper shows that front‐side lateral etching technology is feasible in the fabrication of small vacuum‐sealed cavities and absolute pressure sensors.
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Muhammad Tauseef Sultan, Masood Sadiq Butt, Farhan Saeed and Rizwana Batool
Nigella sativa L. (black cumin) has a unique nutritional profile that can be employed in food formulation to improve health of consumers. Black cumin is already used in…
Abstract
Purpose
Nigella sativa L. (black cumin) has a unique nutritional profile that can be employed in food formulation to improve health of consumers. Black cumin is already used in traditional medicines in Pakistan to treat various maladies like diabetes mellitus, gastrointestinal disorders, and as immune booster. The core objective of the present research study is to explore the role of black cumin fixed oil (BCFO) as a functional ingredient in cereal‐based bakery products.
Design/methodology/approach
The BCFO was supplemented in cookies' formulations and impact on nutritive quality, tocopherols and thymoquinone contents was studied.
Findings
The results indicated that addition of fixed oil influenced the physical characteristics of cookies significantly. Chemical attributes varied non‐significantly, but oxidative stability of the cookies was improved as indicated from decreased peroxide (POV) and TBA value. Gradual increase in BCFO in cookies formulations increased the amounts of total tocopherols significantly from 9.85 ± 0.392 to 53.19 ± 1.689 mg/kg‐oil. BCFO addition significantly enhanced α‐, β‐, γ‐, δ‐tocopherols i.e. 8.80±0.630 to 32.19±1.410, 0.96±0.035 to 3.47±0.114, 0.09 ± 0.000 to 14.98 ± 0.520, 0.00 ± 0.000 to 2.55 ± 0.127 mg/kg‐oil, respectively. Likewise, thymoquinone contents were recorded highest in cookies containing 5.0 @ BCFO (7.25 ± 0.482 mg/100 g) as compared to control. Moreover, cookies containing fixed oil @ 4% rated better on hedonic scale as compared with control by the trained taste panel during sensory evaluation.
Originality/value
The results of present research paved the way for the commercial applications of BCFO especially in cereal‐based products. Moreover, present intervention heightened the prospects of using black cumin seed oil in different food products that may produce healthy impact on end consumers.
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Life is made up of debits and credits, as Kipling wrote, long accounts have to be paid — mistakes, misconduct, misdeeds, all the mischief and harm they cause, exact payment which…
Abstract
Life is made up of debits and credits, as Kipling wrote, long accounts have to be paid — mistakes, misconduct, misdeeds, all the mischief and harm they cause, exact payment which has to be met by someone, not necessarily those that cause the trouble; all too often by innocent victims. The recent industrial strife, destruction and violence, despite the plausible excuses for it, will have disastrous results, a colossal debit in the nation's accounts; and the mass of the people, the vulnerable groups including several millions of elderly pensioners, the handicapped and sick, are under no illusions who will have to pay. The posturing defiance — “heads held high”, bands playing martial music — the complete lack of concern or regret for others will make no difference to the overtaking retribution.
Pradeep Kumar Rathore, Pratyush Varshney, Sunil Prasad and B.S. Panwar
The purpose of this paper is to use finite element method for optimizing the membrane type double cavity vacuum sealed structure for the best achievable sensitivity in a…
Abstract
Purpose
The purpose of this paper is to use finite element method for optimizing the membrane type double cavity vacuum sealed structure for the best achievable sensitivity in a piezoresistive absolute pressure sensor and its validation using a standard complementary metal oxide semiconductor (CMOS) process.
Design/methodology/approach
A double cavity vacuum sealed piezoresistive absolute pressure sensor has been simulated and optimized for its performance and an analytical model describing the behaviour of the sensor has been described. The 1×1 mm sensor chip has two membrane type 100×30×1.7 μm diaphragms consisting of composite layers of plasma enhanced chemical vapour deposition (PECVD) of silicon nitride (Si3N4) and silicon dioxide (SiO2) each hanging over 21 μm deep rectangular cavity. Potassium hydroxide (KOH) based anisotropic etching of single crystal silicon using front side lateral etching technology is used for the fabrication of the sensor. The electrical readout circuitry uses 318 Ω boron diffused low pressure vapour chemical vapour deposition (LPCVD) of polysilicon resistors arranged in the Wheatstone half bridge configuration. The sensing structure is simulated and optimized using COMSOL Multiphysics.
Findings
Front-side lateral etching technology has been successfully used for the fabrication of double cavity absolute pressure sensor. A good agreement with the fabricated device for the chosen location of the piezoresistors through simulation has been predicted. The measured pressure sensitivity of two tested pressure sensors is 12.63 and 12.46 mV/MPa, and simulated pressure sensitivity is found to be 12.9 mV/MPa for pressure range of 0 to 0.5 MPa. The location of the piezoresistor has also been optimized using the simulation tools for enhancing the sensor sensitivity to 62.14 mV/MPa. The pressure sensitivity is further enhanced to 92 mV/MPa by increasing the width of the diaphragm to 35 μm.
Originality/value
The simulated and measured pressure sensitivities of the double cavity pressure sensor are in close agreement. Sevenfold enhancement in the pressure sensitivity of the optimized sensing structure has been observed. The proposed front-side lateral etching technology can be adopted for making membrane type diaphragms hanging over vacuum sealed micro-cavities for high sensitivity pressure sensing applications.
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Waheed Ali, Jun Wen, Hadi Hussain, Nadeem Akhtar Khan, Muhammad Waleed Younas and Ihsan Jamil
In the era of knowledge economy, the significance of intellectual capital has been increasing globally. Similarly, recent studies have focused on the importance of green…
Abstract
Purpose
In the era of knowledge economy, the significance of intellectual capital has been increasing globally. Similarly, recent studies have focused on the importance of green intellectual capital in mitigating environmental degradation. However, only a few studies have analysed green intellectual capital and its impacts in the specific case of Pakistan. Hence, this study aims to investigate the effects of green intellectual capital on green innovation adoption in Pakistan’s manufacturing small and medium-size enterprises (SMEs).
Design/methodology/approach
We used a data sample of 235 SMEs, gathered from the four manufacturing sectors of Pakistan including: textile, chemical, pharmaceutical and steel and analysed using a multiple regression analysis approach.
Findings
The empirical results of this research indicate that green human capital and green structural capital significantly increase green innovation adoption. However, it must be noted that green relational capital has a positive but insignificant impact on green innovation adoption in manufacturing SMEs in Pakistan.
Originality/value
The findings and recommended policy measures of this study are important for the managers of manufacturing SMEs and policymakers to mitigate environmental destruction and achieve sustainable development through green intellectual capital.
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Sonia Najam Shaikh, Li Zhen, Jan Muhammad Sohu, Sanam Soomro, Sadaf Akhtar, Fatima Zahra Kherazi and Suman Najam
In today’s business landscape, drawing upon the critical role of environmental sustainability, this study investigates the intricate relationship between green human resource…
Abstract
Purpose
In today’s business landscape, drawing upon the critical role of environmental sustainability, this study investigates the intricate relationship between green human resource management practices (GHRMP), big data analytics capability (BDAC), green competitive advantage (GCA) and environmental performance (EP), further moderated by managerial environmental concern (MEC).
Design/methodology/approach
This study employs a quantitative approach using the latest version of SmartPLS 4 version 4.0.9.6 on a data sample of 467 participants representing a diverse range of manufacturing SMEs. Data were collected from managers and directors using a structured questionnaire and analyzed using structural equation modeling (SEM). This study contributes to the existing knowledge by integrating GHRMP and BDAC within the GCA framework, providing a comprehensive understanding of how these practices enhance SME`s sustainability.
Findings
The findings provide valuable insights into the manufacturing sector, aiming to enhance SMEs' green competitive advantage. Implementing GHRMP fosters environmental awareness within the workforce, and building BDAC allows for effectively translating that GHRMP into actionable insights, maximizing the potential for achieving GCA. Furthermore, recognizing MEC’s moderating role strengthens positive environmental outcomes associated with GCA. The findings confirm that GHRMP and BDAC are valuable resources and key drivers contributing to competitive advantage in sustainability of enterprises.
Practical implications
For SMEs, our findings suggest that strategically integrating GHRMP with BDAC not only boosts environmental stewardship but also improves operational efficiency and market positioning. This research outlines actionable steps for SMEs aiming to achieve sustainability targets while enhancing profitability. This research provides actionable insights for SMEs in strategic decision-making and policy formulation, aiding SMEs in navigating the complexities of sustainable development effectively.
Originality/value
This study contributes to the existing knowledge by integrating GHRMP and BDAC within the GCA framework, providing a robust theoretical explanation of how HRM practices and BDAC help SMEs gain green competitiveness. The implication of this study reveals that SMEs implementing and integrating green HRM practices with advanced data analytics are more likely to gain competitive advantage. This study draws theoretical support from the resource-based view (RBV) theory, positing that a firm’s sustainable competitive advantage stems from its unique and valuable resources and capabilities that are difficult for competitors to imitate or substitute.
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