Falah Awwad - Academia.edu (original) (raw)

Papers by Falah Awwad

Scientific Reports, Nov 6, 2023

Gas sensing is a critical research area in aerospace, military, medical, and industrial environme... more Gas sensing is a critical research area in aerospace, military, medical, and industrial environments, as it helps prevent risks to human health and the environment caused by toxic gases. Propane and butane, commonly used as fuels in household and industrial settings, are toxic and flammable gases that need to be effectively detected to avoid leakage or explosion accidents. To address this, nanomaterialbased gas sensors are being developed with low power consumption and operating temperatures. In this study, two-dimensional nitrogenated holey graphene (C 2 N) based sensors are used for the first time for the identification of butane and propane gases. The sensor consists of two C 2 N electrodes connected via a C 2 N channel. The C 2 N sensor design was enhanced by replacing the C 2 N electrodes with gold electrodes and adding a gate terminal under the channel. The resistive method is employed to detect butane and propane gases by measuring the variation in the electrical conductivity of the sensor due to exposure to these target molecules. To investigate the electronic transport properties, such as transmission spectra, density of states and current, first principles simulations of the C 2 Nbased sensors is conducted using Quantumwise Atomistix Toolkit (ATK). The detection method relies on the alteration of the FET's electrical current at specific gate voltages due to the presence of these gases. This proposed sensor offers the potential for small size and low-cost gas sensing applications. The designed sensor aims to effectively detect propane and butane gases. By leveraging the unique properties of C 2 N and utilizing advanced simulation tools, this sensor could provide high sensitivity and accuracy in detecting propane and butane gases. Such an advancement in gas sensing technology holds significant promise for ensuring safety in various environments. Gas sensing has attracted significant importance across various areas. The detection of toxic gases is critical to prevent accidents in both household and industrial environments. Therefore, the development of effective tools for detecting the presence of these gases is highly important 1-7. Achieving a high level of sensitivity and resolution is the ultimate objective in gas detection. Detecting the presence of desired gases, even at very low concentrations, is crucial. Despite the use of solid-state gas sensors, achieving such high resolution has remained challenging 2,3,8. The primary cause of the low performance in these devices is attributed to sudden fluctuations and defects caused by the charge carriers thermal motion, resulting in the generation of noise within the device 9. Solid-state gas detectors can be classified into various categories based on their working principles. The most prevalent categories include resistive type sensors, impedance type gas sensors (utilizing alternating current measurements), electrolyte-based gas sensors, and semiconductor gas sensors. Among these, resistive solid-state gas detectors are the most commonly used due to their low fabrication cost and simplicity. These devices operate by detecting changes in the semiconductor material resistance due to its interaction with the target gas. The alteration in resistance is attributed to the movement of charge carriers among the semiconductor material and the target gas 10,11. Impedance-based gas devices exhibit a change in the device frequency response upon exposure to the required gas molecules 12. Conversely, solid-state electrolyte-based gas detectors rely on alterations in the electrolyte ionic conductivity, which occur due to the movement of charge carriers (electrons or holes) from the targeted gas molecules 13. Solid-state gas sensors play a critical role in monitoring and controlling the release of toxic and hazardous gases. However, these sensors do possess certain limitations concerning selectivity, sensitivity, reproducibility, and long-term stability. Despite the increasing demand for gas sensors, there remains a requirement to design sensors that operate at low temperature, highly sensitive, robust, and reversible.

2022 International Conference on Microelectronics (ICM)

In this paper, we propose an antenna selection algorithm for down link MIMO SDMA OFDM system. For... more In this paper, we propose an antenna selection algorithm for down link MIMO SDMA OFDM system. For each user, the data rate corresponding to each transmit antenna is maximized using the optimal bit loading algorithm. A data rate matrix is constructed and used for the antenna selection algorithm assuming the base station (BS) knows the signal-to-noise ratio on all antenna-user pairs of all sub-carriers. In addition to exploiting the multi-user diversity gain, all users are served fairly by the BS. The fairness is achieved through weighting the data rate matrix by a weighting matrix with coefficients inversely proportional to the number of times served for each user. Jain&amp;#x27;s fairness index is used as a measure of the fairness. Simulation results show that a significant increase in the data rate is a achieved compared to the ultimately fair round Robin algorithm, while satisfying a reasonable fairness.

Electronics, Feb 8, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Scientific Reports, Oct 28, 2022

Coronavirus 2019 (COVID-19) spreads an extremely infectious disease where there is no specific tr... more Coronavirus 2019 (COVID-19) spreads an extremely infectious disease where there is no specific treatment. COVID-19 virus had a rapid and unexpected spread rate which resulted in critical difficulties for public health and unprecedented daily life disruption. Thus, accurate, rapid, and early diagnosis of COVID-19 virus is critical to maintain public health safety. A graphite oxide-based field-effect transistor (GO-FET) was fabricated and functionalized with COVID-19 antibody for the purpose of real-time detection of COVID-19 spike protein antigen. Thermal evaporation process was used to deposit the gold electrodes on the surface of the sensor substrate. Graphite oxide channel was placed between the gold electrodes. Bimetallic nanoparticles of platinum and palladium were generated via an ultra-high vacuum (UHV) compatible system by sputtering and inert-gas condensation technique. The biosensor graphite oxide channel was immobilized with specific antibodies against the COVID-19 spike protein to achieve selectivity and specificity. This technique uses the attractive semiconductor characteristics of the graphite oxide-based materials resulting in highly specific and sensitive detection of COVID-19 spike protein. The GO-FET biosensor was decorated with bimetallic nanoparticles of platinum and palladium to investigate the improvement in the sensor sensitivity. The in-house developed biosensor limit of detection (LOD) is 1 fg/mL of COVID-19 spike antigen in phosphate-buffered saline (PBS). Moreover, magnetic labelled SARS-CoV-2 spike antibody were studied to investigate any enhancement in the sensor performance. The results indicate the successful fabrication of a promising field effect transistor biosensor for COVID-19 diagnosis. The 2019-2020 outbreak of COVID-19 virus resulted in thousands of deaths and in worldwide panic 1. The COVID-19 virus is extremely contagious. COVID-19 is not only a health crisis 2 , but it is also causing an economic burden 1. COVID-19 was announced as a global health emergency and pandemic in March 2020 3. World Health Organization (WHO) recommended performing diagnostic tests to stop the COVID-19 transmission and reduce the number of cases. COVID-19 pandemic is considered as a global challenge and researchers are working on vaccines, medicines, and detection mechanisms. Testing is critical for life-saving treatment and isolations of patients to prevent the spread of COVID-19 disease. Biosensing is crucial to detect and control such diseases. Quick diagnostic techniques are critical to reduce and prevent the virus spread rate. One of the critical challenges in fighting COVID-19 is the accurate and rapid identification of infected patients including asymptomatic patients. Identifying those patients helps in applying protective measures such as lockdown and isolating patients which will result in slowing down the transmission rate of the infection. This is an important step for hospitals to provide sufficient supplies, doctors, and rooms to successfully treat the patients who need care. Therefore, diagnostic tests are critical to control the spread of COVID-19 disease. There is a need for new biosensors and diagnostic tests that are accurate, sensitive, reliable, rapid, and cheap. These biosensors should be capable of real-time, and label free identification of the virus in samples without the need for sample

ABSTRACT On-Chip Inductance has become of significance in the design of high-speed interconnects.... more ABSTRACT On-Chip Inductance has become of significance in the design of high-speed interconnects. In this thesis, three techniques are applied to regenerate an RLC: interconnect in series, parallel and without regeneration. Simulations using a 0.25 om TSMC technology show that the parallel regeneration starts achieving a better speed than the non-regenerated line at wire lengths smaller than that achieved when the wire is serially regenerated. It also features 47% time delay saving and 96% Area-Delay product saving over the serial regeneration. Repeaters are now widely used to enhance the performance of long On-Chip interconnects in CMOS VLSI. For RC-modeled interconnects, parallel repeaters have proved to be superior to serial ones. In this thesis, a Variable-Segment Regeneration Technique is introduced and compared with a Variable-Driver Parallel Technique, a recently proposed transparent repeater and with other three conventional techniques. HSpice Simulations using a 0.25 om TSMC technology show that both the variable-segment and variable-driver techniques feature 62% time delay saving and 354% Area-Delay product saving over the transparent repeater, and are superior to all conventional techniques. Moreover, our new variable-segment technique is characterized by a 116% Area-Delay product saving over the variable-driver technique. Thus, making it the most performant in the field of high-performance RLC interconnect regeneration. The simulation results and an analytical model of VSRT confirm the superiority of the parallel regeneration technique over the serial ones.

2022 IEEE Biomedical Circuits and Systems Conference (BioCAS), Oct 13, 2022

Social Science Research Network, 2022

... Concordia University, ECE Dept., Montreal, Quebec, H3H 1M8 Canada Email: { fr-awwad, mnekili ... more ... Concordia University, ECE Dept., Montreal, Quebec, H3H 1M8 Canada Email: { fr-awwad, mnekili 1 @ ece.concordia.ca phone: l(514) 848-4104 ... To avoid the growth of the delay with the square of interconnect length, they recommended to in-sert regularly spaced repeaters in ...

Repeaters are now widely used to enhance the performance of long On-Chip interconnects in CMOS VL... more Repeaters are now widely used to enhance the performance of long On-Chip interconnects in CMOS VLSI. For RC-modeled interconnects, parallel repeaters have proved to be superior to serial ones. In this paper, a Variable-Segment Regeneration Technique is introduced and compared with a Variable-driver Parallel Technique, a recently proposed transparent repeater and with three conventional techniques. HSpice Simulations using a 0.25 µm TSMC technology show that both the variable-segment and variable-driver techniques feature 62% time delay saving and 354% Area-Delay product saving over the transparent repeater, and are superior to all conventional techniques. However, our new variable-segment technique is characterized by a 116% Area-Delay product saving over the variable-driver technique. Thus, making it the most performant in the field of high-performance RLC interconnect regeneration. The simulation results confirm the superiority of the parallel regeneration technique over the serial ones.

ABSTRACT This paper presents a new ISFET readout interface circuitry for Lab-on-Chip applications... more ABSTRACT This paper presents a new ISFET readout interface circuitry for Lab-on-Chip applications. The proposed circuit features a dedicated DC-input sigma delta modulator converting the detected charge to 1-bit digital series. The proposed circuit, designed in 0.35-μm CMOS technology, offers a biologically relevant, high pH dynamic range of 5 to 9 and high sensitivity of 800mV/pH. We demonstrate the features of the proposed circuit by simulations and we discuss the advantage of this low complexity circuit for the measurement of pH using an array of ISFETs suitable for a variety of chemical and biological applications.

Nanomaterials

Multi-gate field effect transistors (FETs) such as FinFETs are severely affected by short-channel... more Multi-gate field effect transistors (FETs) such as FinFETs are severely affected by short-channel effects (SCEs) below 14 nm technology nodes, with even taller fins incurring fringing capacitances. This leads to performance degradation of the devices, which inhibits further scaling of nanoFETs, deterring the progress of semiconductor industries. Therefore, research has not kept pace with the technological requirements of the International Roadmap for Devices and Systems (IRDS). Thus, the development of newer devices with superior performances in terms of higher ON currents, acceptable leakage currents and improved SCEs is needed to enable the continuance of integrated circuit (IC) technologies. The literature has advocated integration of strained-silicon technology in existing FinFETs, which is highly effective in enhancing ON currents through the strain effect. However, the ON currents can also be amplified by intensifying the number of fins in trigate (TG) FinFETs. Thus, three-fin...

Energies

Microgrid technology has recently gained global attention over increasing demands for the inclusi... more Microgrid technology has recently gained global attention over increasing demands for the inclusion of renewable energy resources in power grids, requiring constant research and development in aspects such as control, protection, reliability, and management. With an ever-increasing scope for maximizing renewable energy output, there is also a need to reduce the curtailment of power on both the generation and demand sides by increasing forecasting accuracies and using resources more effectively. This paper proposes a dual-stage dispatch employing a novel “split-horizon” strategy, in a bid to enhance energy management in a standalone microgrid. The split-horizon is essentially the considered time horizon split into equal operational periods of the dual-stage dispatch. The proposed strategy utilizes a custom-designed novel variant of the inertia-weight-based particle swarm optimization (PSO), termed customized PSO, to perform the optimal schedule and dispatch operation by benefitting f...

Scientific Reports

Graphene field effect transistor (FET) biosensors have attracted huge attention in the point-of-c... more Graphene field effect transistor (FET) biosensors have attracted huge attention in the point-of-care and accurate detection. With the recent spread of the new emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the need for rapid, and accurate detection & screening tools is arising. Employing these easy-to-handle sensors can offer cheap, rapid, and accurate detection. Herein, we propose the design of a reduced graphene oxide (rGO) FET biosensor for the detection of SARS-CoV-2. The main objective of this work is to detect the SARS-CoV-2 spike protein antigen on spot selectively and rapidly. The sensor consists of rGO channel, a pair of golden electrodes, and a gate underneath the channel. The channel is functionalized with COVID-19 spike protein antibodies to achieve selectivity, and with metal nanoparticles (MNPs) such as copper and silver to enhance the bio-sensing performance. The designed sensor successfully detects the SARS-CoV-2 spike protein and shows singul...

Nanomaterials

Real-time detection of sugar molecules is critical for preventing and monitoring diabetes and for... more Real-time detection of sugar molecules is critical for preventing and monitoring diabetes and for food quality evaluation. In this article, a field effect transistor (FET) based on two-dimensional nitrogenated holey graphene (C2N) was designed, developed, and tested to identify the sugar molecules including xylose, fructose, and glucose. Both density functional theory and non-equilibrium Green’s function (DFT + NEGF) were used to study the designed device. Several electronic characteristics were studied, including work function, density of states, electrical current, and transmission spectrum. The proposed sensor is made of a pair of gold electrodes joint through a channel of C2N and a gate was placed underneath the channel. The C2N monolayer distinctive characteristics are promising for glucose sensors to detect blood sugar and for sugar molecules sensors to evaluate food quality. The electronic transport characteristics of the sensor resulted in a unique signature for each of the ...

Analog Integrated Circuits and Signal Processing

Scientific Reports

2018 IEEE Electrical Power and Energy Conference (EPEC)

With the increase in renewable energy integration in the electrical power systems along with incr... more With the increase in renewable energy integration in the electrical power systems along with increase in the time-varying energy consumption by the users, it is imperative to regulate the load profile through pragmatic economical Demand-Side Management. Thus, the study carried out in this paper presents a real-time algorithm for cost optimization to achieve Demand-Side Management of a Renewable Energy Source integrated microgrid. The algorithm aims to achieve utility maximization and cost reduction for an optimal power scheduling in the presence of variable loads. The proposed approach mitigates the continuous changes in the variable loads that emulates the load profile found in residential, commercial and industrial users. The particular focus of this work is on developing a decentralized control scheme and a utility-oriented energy community, which provides user satisfaction based on energy management system, production units and load demand. Moreover, the paper presents utility maximization solutions on the combined energy profile of the microgrid targeting two main objectives, i.e., (1) minimizing the aggregate energy cost and (2) maximizing the provider's and user's satisfaction. Minimizing the aggregate energy cost aims to reduce the peak to average ratio of the aggregate energy profile of the microgrid using the cost function for energy cost minimization. The proposed technique is tested on microgrid which is coordinated in master-slave control topology. The implemented algorithm ensures a stable and efficient operation of the microgrid while minimizing the total cost of production.

2018 IEEE International Symposium on Circuits and Systems (ISCAS), 2018

The recent advancements in system-on-chip (SoC) and network-on-chip (NoC) have enormously increas... more The recent advancements in system-on-chip (SoC) and network-on-chip (NoC) have enormously increased the number of on-chip frequency domains that are originating from multiple on-chip clock sources. In modern battery-operated internet of things (IoT) devices, limited power budget and requirement for complex clock distribution schemes increases the usage clock multipliers. These multiple clock signal requirements are usually catered for by using frequency multipliers with clock generators. However, most of these multipliers are based on analog components that require a customized layout, involve timing uncertainties, and are power hungry and highly prone to mismatches in the process variations and environmental changes. Moreover, in modern battery-operated smart devices for IoT have very limited power budget, which makes the design of clock multipliers even more challenging. To address these issues, we propose a delay-based digital frequency multiplier, which uses 2-input XNOR gates and a true single-phase clock (TSPC) flip-flop because of pulse generation and edge detection properties, respectively. The proposed multiplier is based on the digital components, therefore, it reduces the power consumption significantly, i.e., 1.6mW, which is almost 50% lesser than other low power state-of-the-art designs. Moreover, it can operate for a wide range of input frequencies, ∼400MHz to 1GHz. The Monte-Carlo simulation results are very promising as they indicate the robustness of the design against process and environmental variations.

Scientific Reports, Nov 6, 2023

2022 International Conference on Microelectronics (ICM)

Electronics, Feb 8, 2023

Scientific Reports, Oct 28, 2022

2022 IEEE Biomedical Circuits and Systems Conference (BioCAS), Oct 13, 2022

Social Science Research Network, 2022

Nanomaterials

Energies

Scientific Reports

Nanomaterials

Analog Integrated Circuits and Signal Processing

Scientific Reports

2018 IEEE Electrical Power and Energy Conference (EPEC)

2018 IEEE International Symposium on Circuits and Systems (ISCAS), 2018