Khaled Kirah

Bio: Khaled Kirah is an academic researcher from Ain Shams University. The author has contributed to research in topics: Energy conversion efficiency & Silicon. The author has an hindex of 10, co-authored 37 publications receiving 277 citations. Previous affiliations of Khaled Kirah include French University in Egypt.

Hybrid plasmonic electro-optical modulator

Abstract: A high-performance CMOS compatible electro-optical modulator (EOM) is proposed, simulated and analyzed. The EOM is based on an asymmetric hybrid plasmonic waveguide on a silicon-on-insulator platform. Using the finite difference time domain simulation method, we obtained the transmission spectrum of the modulator. An insertion loss of 0.25 dB is achieved for a 5-μm-short modulator. The extinction ratio is optimized to be as high as 30 dB at a wavelength of 1.55 μm. Broadband operation of 600 nm is feasible since no resonator is deployed .

Integrated optical sensor using hybrid plasmonics for lab on chip applications

Abstract: We propose a novel, compact plasmonic sensing structure based on a metal–insulator–metal waveguide hybridly-coupled to a rectangular side cavity. The structure has been numerically investigated using the finite-difference time-domain method. Transmission spectra obtained from numerical simulations are used to analyze the sensing characteristics of the structure. The effects of the geometrical parameters on transmission and sensing of the structure are studied. With optimum design, sensitivity can reach as high as 1500 nm per refractive-index unit around the resonance wavelength of 1550 nm with a cavity area of 1 μm2. The proposed structure can potentially be applied in on-chip pressure and gas micro-sensors.

Ballistic transport in Schottky barrier carbon nanotube FETs

Abstract: Simulation of Schottky barrier carbon nanotube field effect transistors (SB-CNTFETs) is presented to yield the electrostatic potential, carrier concentration and current within the device. The simulator is based on a self-consistent solution of Poisson's equation and the carrier transport equation. The finite element method is used for solving Poisson's equation while the non-equilibrium Green's function formalism is used to model the carrier transport. The developed simulator is used to investigate the effects of device parameters on device performance.

Inkjet printed nanomaterial based flexible radio frequency identification (RFID) tag sensors for the internet of nano things

Abstract: The Internet of Things (IoT) has limitless possibilities for applications in the entire spectrum of our daily lives, from healthcare to automobiles to public safety. The IoT is expected to grow into a trillion dollar industry worldwide over the next decade. The components of the IoT will be integrated with cloud computing, which will facilitate easy access and analysis of big data stored in cloud systems across the globe. Radio frequency identification (RFID) technology is based on wireless communication systems and offers easy integration into the Internet cloud system. The potential of RFID tag sensor technologies has been studied in different industrial sectors including healthcare, food safety, environmental pollution, anti-counterfeiting of bank-notes and fake medicines, factories, customer shopping behavior, logistics, public transport, and safety. In this review article, the role of inkjet-printed RFID tag sensors is described in the emerging fields of IoT and the Internet of Nano Things (IoNT). This review is concerned with the use of inkjet-printed nanomaterials to fabricate RFID-enabled devices as a component of IoT technology. Inkjet-printed flexible RFID tag sensors based on nanomaterials including multilayer graphene, carbon nanotubes, gold, silver and copper nanoparticles, conductive polymers and their based composites used for detecting toxic gases and chemicals are discussed. Inkjet-printed nanomaterial-based RFID tag sensors that can be easily printed on flexible paper, plastic, textile, glass, and metallic surfaces, show potential in flexible and wearable electronics technologies. Finally, challenges such as energy and safety issues for RFID tag sensors are analyzed.

Flexible Antennas: A Review.

Abstract: The field of flexible antennas is witnessing an exponential growth due to the demand for wearable devices, Internet of Things (IoT) framework, point of care devices, personalized medicine platform, 5G technology, wireless sensor networks, and communication devices with a smaller form factor to name a few. The choice of non-rigid antennas is application specific and depends on the type of substrate, materials used, processing techniques, antenna performance, and the surrounding environment. There are numerous design innovations, new materials and material properties, intriguing fabrication methods, and niche applications. This review article focuses on the need for flexible antennas, materials, and processes used for fabricating the antennas, various material properties influencing antenna performance, and specific biomedical applications accompanied by the design considerations. After a comprehensive treatment of the above-mentioned topics, the article will focus on inherent challenges and future prospects of flexible antennas. Finally, an insight into the application of flexible antenna on future wireless solutions is discussed.

Self-Powered Implantable Medical Devices: Photovoltaic Energy Harvesting Review.

Abstract: Implantable technologies are becoming more widespread for biomedical applications that include physical identification, health diagnosis, monitoring, recording, and treatment of human physiological traits. However, energy harvesting and power generation beneath the human tissue are still a major challenge. In this regard, self-powered implantable devices that scavenge energy from the human body are attractive for long-term monitoring of human physiological traits. Thanks to advancements in material science and nanotechnology, energy harvesting techniques that rely on piezoelectricity, thermoelectricity, biofuel, and radio frequency power transfer are emerging. However, all these techniques suffer from limitations that include low power output, bulky size, or low efficiency. Photovoltaic (PV) energy conversion is one of the most promising candidates for implantable applications due to their higher-power conversion efficiencies and small footprint. Herein, the latest implantable energy harvesting technologies are surveyed. A comparison between the different state-of-the-art power harvesting methods is also provided. Finally, recommendations are provided regarding the feasibility of PV cells as an in vivo energy harvester, with an emphasis on skin penetration, fabrication, encapsulation, durability, biocompatibility, and power management.

Epsilon-near-zero photonics: infinite potentials

Abstract: With its unique and exclusive linear and nonlinear optical characteristics, epsilon-near-zero (ENZ) photonics has drawn a tremendous amount of attention in the recent decade in the fields of nanophotonics, nonlinear optics, plasmonics, light-matter interactions, material science, applied optical science, etc. The extraordinary optical properties, relatively high tuning flexibility, and CMOS compatibility of ENZ materials make them popular and competitive candidates for nanophotonic devices and on-chip integration in all-optical and electro-optical platforms. With exclusive features and high performance, ENZ photonics can play a big role in optical communications and optical data processing. In this review, we give a focused discussion on recent advances of the theoretical and experimental studies on ENZ photonics, especially in the regime of nonlinear ENZ nanophotonics and its applications. First, we overview the basics of the ENZ concepts, mechanisms, and nonlinear ENZ nanophotonics. Then the new advancements in theoretical and experimental optical physics are reviewed. For nanophotonic applications, the recent decades saw rapid developments in various kinds of different ENZ-based devices and systems, which are discussed and analyzed in detail. Finally, we give our perspectives on where future endeavors can be made.