Enhanced Optical Management in Organic Solar Cells by Virtue of Square-Lattice Triple Core-Shell Nanostructures.

This research focuses on enhancing the optical efficacy of organic photovoltaic cells, specifically their optical absorbance and electrical parameters. The absorbance of photons in organic solar cells (OSCs) was studied by incorporating an optical space layer and triple core-shell square-lattice nanostructures. For better chemical and thermal stability, a dielectric-metal-dielectric nanoparticle can be replaced for embedded metallic nanoparticles in the absorption layer. The 3D (finite-difference time-domain) FDTD method was used to analyze the absorption and field distribution in OSCs using 3D model morphology. Firstly, an optimization of thickness of the optical spacer layer was analyzed and secondly, the impact of adding triple core-shell nanostructures at different levels of an OSC were studied. The photovoltaic properties such as short circuit current density, power conversion efficiency, fill factor, Voc were investigated. The proposed design has demonstrated an improvement of up to 80% in the absorption of light radiation in the photoactive region (donor or acceptor) of OSCs in the wavelength range of 400 nm to 900 nm when compared with that of nanostructures proposed at various layers of OSC.

A Comprehensive Review of Bio-Inspired Optimization Algorithms Including Applications in Microelectronics and Nanophotonics.

The application of artificial intelligence in everyday life is becoming all-pervasive and unavoidable. Within that vast field, a special place belongs to biomimetic/bio-inspired algorithms for multiparameter optimization, which find their use in a large number of areas. Novel methods and advances are being published at an accelerated pace. Because of that, in spite of the fact that there are a lot of surveys and reviews in the field, they quickly become dated. Thus, it is of importance to keep pace with the current developments. In this review, we first consider a possible classification of bio-inspired multiparameter optimization methods because papers dedicated to that area are relatively scarce and often contradictory. We proceed by describing in some detail some more prominent approaches, as well as those most recently published. Finally, we consider the use of biomimetic algorithms in two related wide fields, namely microelectronics (including circuit design optimization) and nanophotonics (including inverse design of structures such as photonic crystals, nanoplasmonic configurations and metamaterials). We attempted to keep this broad survey self-contained so it can be of use not only to scholars in the related fields, but also to all those interested in the latest developments in this attractive area.

Smart City IoT System Network Level Routing Analysis and Blockchain Security Based Implementation.

This paper demonstrates, network-level performance analysis and implementation of smart city Internet of Things (IoT) system with Infrastructure as a Service (IaaS) level cloud computing architecture. The smart city IoT network topology performance is analyzed at the simulation level using the NS3 simulator by extracting most of the performance-deciding parameters. The performance-enhanced smart city topology is practically implemented in IaaS level architecture. The intended smart city IoT system can monitor the principal parameters like video surveillance with a thermal camera (to identify the virus-like COVID-19 infected people), transport, water quality, solar radiation, sound pollution, air quality (O3, NO2, CO, Particles), parking zones, iconic places, E-suggestions, PRO information over low power wide area network in 61.88 km × 61.88 km range. Primarily we have addressed the IoT network-level routing and quality of service (QoS) challenges and implementation level security challenges. The simulation level network topology analysis is performed to improve the routing and QoS. Blockchain technology-based decentralization is adopted to enrich the IoT system performance in terms of security.

Investigation of Nonlinear Piezoelectric Energy Harvester for Low-Frequency and Wideband Applications.

This paper proposes a monostable nonlinear Piezoelectric Energy Harvester (PEH). The harvester is based on an unconventional exsect-tapered fixed-guided spring design, which introduces nonlinearity into the system due to the bending and stretching of the spring. The physical-mathematical model and finite element simulations were performed to analyze the effects of the stretching-induced nonlinearity on the performance of the energy harvester. The proposed exsect-tapered nonlinear PEH shows a bandwidth and power enhancement of 15.38 and 44.4%, respectively, compared to conventional rectangular nonlinear PEHs. It shows a bandwidth and power enhancement of 11.11 and 26.83%, respectively, compared to a simple, linearly tapered and nonlinear PEH. The exsect-tapered nonlinear PEH improves the power output and operational bandwidth for harvesting low-frequency ambient vibrations.

A comprehensive review on advancements in tissue engineering and microfluidics toward kidney-on-chip.

This review provides a detailed literature survey on microfluidics and its road map toward kidney-on-chip technology. The whole review has been tailored with a clear description of crucial milestones in regenerative medicine, such as bioengineering, tissue engineering, microfluidics, microfluidic applications in biomedical engineering, capabilities of microfluidics in biomimetics, organ-on-chip, kidney-on-chip for disease modeling, drug toxicity, and implantable devices. This paper also presents future scope for research in the bio-microfluidics domain and biomimetics domain.

Optimized Design of a Self-Biased Amplifier for Seizure Detection Supplied by Piezoelectric Nanogenerator: Metaheuristic Algorithms versus ANN-Assisted Goal Attainment Method.

This work is dedicated to parameter optimization for a self-biased amplifier to be used in preamplifiers for the diagnosis of seizures in neuro-diseases such as epilepsy. For the sake of maximum compactness, which is obligatory for all implantable devices, power is to be supplied by a piezoelectric nanogenerator (PENG). Several meta-heuristic optimization algorithms and an ANN (artificial neural network)-assisted goal attainment method were applied to the circuit, aiming to provide us with the set of optimal design parameters which ensure the minimal overall area of the preamplifier. These parameters are the slew rate, load capacitor, gain-bandwidth product, maximal input voltage, minimal input voltage, input voltage, reference voltage, and dissipation power. The results are re-evaluated and compared in the Cadence 180 nm SCL environment. It has been observed that, among the metaheuristic algorithms, the whale optimization technique reached the best values at low computational cost, decreased complexity, and the highest convergence speed. However, all metaheuristic algorithms were outperformed by the ANN-assisted goal attainment method, which produced a roughly 50% smaller overall area of the preamplifier. All the techniques described here are applicable to the design and optimization of wearable or implantable circuits.

Design and Modeling of Bioreactor Utilizing Electrophoresis and Di-Electrophoresis Techniques for Regenerating Reabsorption Function of Human Kidney PCT in Microfluidics Environment.

The need for innovation in medical device technology is immense; especially to replace dialysis techniques the necessity is extremely high. Available techniques that promised to replace dialysis have not yet geared up to the marketization level. The utilization of live kidney cells makes these devices costly, delicate, and unreliable. This paper aims to design a bioreactor to mimic the reabsorption function of the kidney that is fully artificial and highly controllable, which can be one step forward to the emerging Kidney-on-Chip (KOC) technology. The additional benefit of the proposed design is that it utilizes size-dependent reabsorption along with charge-dependent reabsorption phenomena to make it more compatible with human kidney function. The electrophoresis (EP), and di-electrophoresis (DEP) techniques are utilized to mimic the reabsorption function in this report. The structure utilized in the present design exactly replicates the proximal convoluted tubule (PCT) dimensions and functions as well. The whole setup is implemented in the COMSOL Multiphysics FEM benchmark tool for simulation, and analysis with appropriate boundary conditions. The device when excited by an electric field, Electrophoresis has produced a maximum velocity of 1.07 m/s for DC excitation and di-electrophoresis has produced a maximum flow velocity of 1.23 m/s, where both the offset voltages are the same (0.7 V). The flow velocity obtained utilizing both EP and DEP produced a reabsorption rate of 50-58% depending on the voltage applied and dimensions considered which is close to 60% reabsorption rate of the normal human kidney PCT. In accordance with the outcomes produced, the di-electrophoresis technique proved to be more efficient in realizing bioreactor as compared to electrophoresis. The novelty of the present work lies in the creation of a simulation environment, rigorous analysis, and optimization of the bioreactor supported by compact mathematical model.

Design, simulation and analysis of micro electro-mechanical system microneedle for micropump in drug delivery systems.

This article reports on the mechanical strength analysis and flow characteristics of square tip and circular tip microneedles by employing highly potent drugs that are given in extremely little quantity (microlitres) using MEMS technology, which proves to be a significant component of micropump in the application of Bio-MEMS. These microneedles are well suitable for a MEMS-based micropump in the drug delivery systems. It is an essential part of the micropump through which the drug is released into the patient's body. The proposed microneedles can withstand a stress of 23 MPa and 20 KPa. An extensive investigation on selection of material for the microneedle is carried out to meet the requirements of the biocompatibility and high yield, as well as tensile strength. As mighty drugs such as vasopressin, atropine and digoxin are administered in large quantities, the microneedle is designed so as to deliver 800 µl of drug, with each microneedle delivering 90 µl. in a 3 3 array. 3 × 3 array releasing 90 µl.

Temporal response of biochemical and biological sensors with bimodal surface adsorption from a finite sample.

The importance of adsorption-based biochemical/biological sensors in biochemistry and biophysics is paramount. Their temporal response gives information about the presence of a biochemical/biological analyte, its concentration and its interactions with the adsorption sites (which may be an integral part of the surface itself or immobilized functionalizing molecules). Mathematical models of the temporal response taking into account as many relevant effects as possible are essential for obtaining reliable information. We present a novel model taking into account the bimodal affinity of a sensing surface (adsorption occurs on two distinct site types), and the adsorption-caused depletion of the analyte from the sample. We perform qualitative and quantitative analysis of the analyte depletion influence on the bimodal adsorption, and of the influence of the sensing surface inhomogeneity on the sensor temporal response, for different analyte concentrations and different fractions of two types of adsorption sites. Since the presented mathematical model deals with the realistic cases of the sensing surface non-uniformity and the finite amount of analyte present in the sensor reaction chamber, it enables improved accuracy in interpreting the measurement data. Our results are general, i.e. valid for any adsorption sensor (microcantilevers, plasmonics) and for arbitrary sensor dimensions.

Recreating the size-dependent reabsorption function of proximal convoluted tubule towards artificial kidney applications: Structural analysis and computational study.

Human kidneys tend to be affected adversely and fail to function more often than any other organ in the body because of diet, heredity, and lifestyle of a person. Dialysis is the technique presently in use for replacing the failed kidney function but it is packed with painfulness, bulkiness, and is costly also. There is a growing need for development of an artificial kidney that eradicates the problems associated with dialysis. This article proposes a structure that mimics the most important aspect of the human kidney: the size-dependent reabsorption of endothelial cells in the proximal convoluted tubule (PCT). The proposed structure consists of transporting channels connecting blood tubules surrounded on both sides of a main tubule. Geometries of the channels are analyzed for optimum flow by varying angles with respect to the main tubule. The analytical formulae have been developed by considering proper boundary conditions governing the flow in the structure, which makes the model as robust, concise, and realistic as the actual PCT. The mathematical model is validated against the benchmark FEM tool COMSOL Multiphysics and the results seem to be satisfactory. This article concludes, that slant channels possess a considerably higher average flow velocity of 5.39 × 10-5  m/s (≈52% reabsorption rate) than straight channels with 4.77 × 10-5  m/s (≈46% reabsorption rate) which is closer to the actual PCT reabsorption rate of 60%. The proposed model is first of its kind in nature among the reported works which creates and exhibits simulation environment of PCT reabsorption function supported by mathematical formulation and also can be useful to study and develop artificial kidney in near future.