Lauren E. Kreno, Kirsty Leong, O. Farha et al.

Chemical Reviews • 2012

1. INTRODUCTION Among the classes of highly porous materials, metalÀorganic frameworks (MOFs) are unparalleled in their degree of tunability and structural diversity as well as their range of chemical and physical properties. MOFs are extended crystalline structures wherein metal cations or clusters of cations (" nodes ") are connected by multitopic organic " strut " or " linker " ions or molecules. The variety of metal ions, organic linkers, and structural motifs affords an essentially infinite number of possible combinations. 1 Furthermore, the possibility for postsynthetic modification adds an additional dimension to the synthetic variability. 2 Coupled with the growing library of experimentally determined structures, the potential to computationally predict, with good accuracy, affinities of guests for host frameworks points to the prospect of routinely predesigning frameworks to deliver desired properties. 3,4 MOFs are often compared to zeolites for their large internal surface areas, extensive porosity, and high degree of crystallinity. Correspondingly, MOFs and zeolites have been utilized for many of the same applications

Zexin Wu, Yangtian Ye, Zijun Guo et al.

Organic & Biomolecular Chemistry • 2024

Mainly owing to their well-defined pore structures and high surface areas, metal-organic frameworks (MOFs) have recently become a versatile class of materials for enzyme immobilization. Nevertheless, most previous studies were focused on model enzymes such as cytochrome c, catalase, and glucose oxidase, with the application of MOF-derived biocomposites for (asymmetric) organic synthesis being rare. In the present work, the immobilization of the ketoreductase KmCR2 onto the zeolitic imidazolate framework (ZIF), a prominent type of MOF, was pursued using the controlled co-precipitation strategy, with a low 2-methylimidazole (2-mIM)/Zn molar ratio of 8 : 1 being employed. Such fabricated biocomposites denoted as KmCR2@ZIF were found to exist mainly in an amorphous phase, as suggested by the scanning electron microscopy (SEM) and powder X-ray diffraction (PXRD) data. Improved thermal and storage stabilities were observed for KmCR2@ZIF compared with the free enzyme. Stereoselective reduction of nine diarylmethanones 1 catalyzed by KmCR2@ZIF was performed, and the corresponding enantioenriched diarylmethanols 2 were afforded in 40-92% conversions with good to excellent optical purities (up to >99% ee). Critically, the current work demonstrated that the unique characteristic of KmCR2, namely the substituent position-controlled stereospecificity (meta versus para or ortho), was not altered upon the enzyme immobilization onto the ZIF.

Aishwarya Prakash, Suma Basappa, Bhavya Jeebula et al.

Organic Letters • 2024

We report a recyclable and efficient catalyst system based on a nickel-benzene tricarboxylic acid metal-organic framework (Ni-BTC MOF) for the borylation of aryl halides, including aryl chlorides, with bis(pinacolato)diboron, affording aryl boronate esters in high yields (up to >99% yield) with high selectivity. This protocol demonstrates broad functional group tolerance. Catalyst can be recyclable up to four times, and gram-scale reactions further highlights the usefulness of this method. In situ EPR experiments confirmed the formation of catalytically active Ni(I) species.

Xi Chen, Tingting Xiao, Yanan Liu et al.

Chemistry – A European Journal • 2025

The formation of biofilm has become a significant influencing factor to microbial fuel cells (MFCs). Developing effective biofilm detection means are highly imperative for improving the efficiency of MFCs. In this study, we propose a two-dimensional metal-organic framework (2D Cu-BDC) nanozyme-based impedance detector for the simultaneous detection and removal of bacterial biofilms. The promising induction interface features good electron transfer and biofilm attachment properties, realizing sensitive biofilm detection. The impedance response change on the functionalized 2D MOF detector was 3.5 times higher for Gram-positive bacteria biofilm and 2.7 times higher for Gram-negative bacteria biofilm compared to bare electrodes. In addition, the 2D MOF nanozyme demonstrates robust peroxidase-like activity, enabling efficient biofilm degradation at low H2O2 concentration, and further allowing for real-time monitoring of the biofilm elimination process. This study provides a novel approach to using MOF-based biosensors for the simultaneous detection and removal of biofilm in MFCs.

Vidushi Aggarwal, Shipra Solanki, B. Malhotra

Chemical Science • 2022

Metal–organic frameworks (MOFs) are an emerging class of porous nanomaterials that have opened new research possibilities. The inherent characteristics of MOFs such as their large surface area, high porosity, tunable pore size, stability, facile synthetic strategies and catalytic nature have made them promising materials for enormous number of applications, including fuel storage, energy conversion, separation, and gas purification. Recently, their high potential as ideal platforms for biomolecule immobilization has been discovered. MOF-enzyme-based materials have attracted the attention of researchers from all fields with the expansion of MOFs development, paving way for the fabrication of bioelectrochemical devices with unique characteristics. MOFs-based bioelectrodes have steadily gained interest, wherein MOFs can be utilized for improved biomolecule immobilization, electrolyte membranes, fuel storage, biocatalysis and biosensing. Likewise, applications of MOFs in point-of-care diagnostics, including self-powered biosensors, are exponentially increasing. This paper reviews the current trends in the fabrication of MOFs-based bioelectrodes with emphasis on their applications in biosensors and biofuel cells.

Bernhard Auer, Shane G. Telfer, A. J. Gross

Electroanalysis • 2022

Abstract Metal organic frameworks (MOFs) with their high pore volumes and chemically‐diverse pore environments have emerged as components of catalytic electrodes for biosensors, biofuel cells, and bioreactors. MOFs are widely exploited for gas capture, separations, and catalysis, but their integration at electrodes with biocatalysts for (bio)electrocatalysis is a niche topic that remains largely unexplored. This review focuses on recent advances in MOF and MOF‐derived carbon electrodes for bioelectrochemical applications. A range of MOF materials and their integration into devices with enzymes and microbes are reported. Key properties and performance characteristics are considered and opportunities facing MOFs for (bio)electrochemical applications are discussed.

Mengjie Fan, Hui Li, Liuhong Wang et al.

Sustainability • 2024

Microbial fuel cells (MFCs) can realize the conversion of chemical energy to electrical energy in high-salt wastewater, but the easily deactivated cathode seriously affects the performance of MFCs. To enhance the stability and sustainability of MFC in such circumstances, a bimetallic organic framework ZIF-8/ZIF-67 was utilized for the synthesis of a carbon cage-encapsulated metal catalysts in this study. Catalysts with different Co and Ce ratio (Co@C (without the Ce element), CoCe0.25@C, CoCe0.5@C, and CoCe1@C) were employed to modify the activated carbon cathodes of MFCs. The tests demonstrated that the MFCs with the CoCe0.5@C cathode catalyst obtained the highest maximum power density (188.93 mW/m2) and the smaller polarization curve slope, which boosted the electrochemical activity of microorganisms attached to the anode. The appropriate addition of the Ce element was conductive to the stability of the catalyst’s active center, which is beneficial for the stability of catalytic performance. Under the function of the CoCe0.5@C catalyst, the MFCs exhibited superior and stable norfloxacin (NOR) degradation efficiency. Even after three cycles, the NOR degradation rate remained at 68%, a negligible 5.6% lower than the initial stage. Furthermore, based on the analysis of microbial diversity, the abundance of electrogenic microorganisms on a bioanode is relatively high with CoCe0.5@C as the cathode catalyst. This may be because the better cathode oxygen reduction reaction (ORR) performance can strengthen the metabolic activity of anode microorganisms. The electrochemical performance and NOR degradation ability of MFC were enhanced in a high-salt environment. This paper provides an approach to address the challenge of the poor salt tolerance of cathode catalysts in MFC treatment, and presents a new perspective on resource utilization, low carbon emissions, and the sustainable treatment of high-salt wastewater.

S. Roh, H. Woo

Journal of Nanoscience and Nanotechnology • 2015

Microbial fuel cells (MFCs) are bio-electrochemical system that can convert biomass spontaneously into electricity through the metabolic activity of microorganisms. We constructed MFCs of polypyrrole (PPy) coated carbon nanotube (CNT) composite as an electrode material and Shewanella oneidensis as the biocatalyst to increase power density. The PPy-coated CNT were synthesized by the in-situ chemical polymerization of pyrrole on CNT, and the electrochemical properties and performance of the modified electrode as an anode in MFC were then investigated. Treatment with 0.1 wt% Ge-132 on the acid-treated MWNTs helped to form better PPy-MWNT composite. The PPy-CNT/CF anode showed a noteworthy 38% power production improvement when compared to plain CF anode. The PPy-CNT composite could be a very efficient and promising electrode material for electricity generation of MFC.

H. Tsai, W. Hsu, Ying Huang

Journal of Nanomaterials • 2015

Microbial fuel cells (MFCs), which can generate low-pollution power through microbial decomposition, have become a potentially important technology with applications in environmental protection and energy recovery. The electrode materials used in MFCs are crucial determinants of their capacity to generate electricity. In this study, we investigate the performance of using carbon nanotube (CNT) and graphene-modified carbon-cloth electrodes in a single-chamber MFC. We develop a process for fabricating carbon-based modified electrodes and Escherichia coli HB101 in an air-cathode MFC. The results show that the power density of MFCs can be improved by applying a coat of either graphene or CNT to a carbon-cloth electrode, and the graphene-modified electrode exhibits superior performance. In addition, the enhanced performance of anodic modification by CNT or graphene was greater than that of cathodic modification. The internal resistance decreased from 377 kΩ for normal electrodes to 5.6 kΩ for both electrodes modified by graphene with a cathodic catalyst. Using the modified electrodes in air-cathode MFCs can enhance the performance of power generation and reduce the associated costs.

K. Fei, Tian-shun Song, Haoqi Wang et al.

Royal Society Open Science • 2017

For Cr(VI)-removal microbial fuel cell (MFC), a more efficient biocathode in MFCs is required to improve the Cr(VI) removal and electricity generation. RVC-CNT electrode was prepared through the electrophoretic deposition of carbon nanotube (CNT) on reticulated vitreous carbon (RVC). The power density of MFC with an RVC-CNT electrode increased to 132.1 ± 2.8 mW m−2, and 80.9% removal of Cr(VI) was achieved within 48 h; compared to only 44.5% removal of Cr(VI) in unmodified RVC. Cyclic voltammetry, energy-dispersive spectrometry and X-ray photoelectron spectrometry showed that the RVC-CNT electrode enhanced the electrical conductivity and the electron transfer rate; and provided more reaction sites for Cr(VI) reduction. This approach provides process simplicity and a thickness control method for fabricating three-dimensional biocathodes to improve the performance of MFCs for Cr(VI) removal.

B. Deeraj, K. Jayanarayanan, Joseph Kuruvilla et al.

Journal of Siberian Federal University. Biology • 2018

In the present work, microfibrillar composites (MFCs) based on polypropylene (PP) /Nylon 6 (NY) blends, along with multi walled carbon tubes (MWCNT) were prepared by melt processing technique. The blending of the fibre forming polymers was carried out in a twin screw extruder with varying concentrations of MWCNT. The drawing of the extruded strands was accomplished in a stretching unit followed by isotropization by compression moulding at a processing temperature below the melting point of NY. At an optimized fixed composition of PP/NY (70/30 w/w %), the influence of stretch ratio on the properties of nanofiller incorporated MFCs was investigated. The morphology development of the MFC samples was observed using high resolution scanning electron microscopy (HRSEM). The static mechanical studies signify the constructive effect of microfibrils and MWCNTs in reinforcing PP matrix. Dynamic rheological studies support the microfibrils contribution towards the stiffness of the system.

C. Ngaw, Cui-e Zhao, V. B. Wang et al.

Sustainable Energy & Fuels • 2017

Poor extracellular electron transfer (EET) between microorganisms and the anode in microbial fuel cells (MFCs) has been the limiting factor hindering the widespread application of this technology. Thus, the employment of high performance anodes with efficient EET is crucial in enhancing the overall performance of MFCs. This work exploits the effect of MFC anodes with superior EET on significantly improving solar microbial hybrid technology formed by coupling a high performance MFC with a photoelectrochemical (PEC) cell. Based on the results, the hybrid device, which comprises a graphene/carbon nanotube (G/CNT) based MFC and a gold/titanium dioxide (Au/TiO2) PEC cell, generated a photocurrent density of ∼0.758 mA cm−2 and a H2 evolution rate of ∼11.2 μmol h−1. This performance is ∼2.5 times higher than that of an unmodified carbon bio-anode (∼0.294 mA cm−2, ∼4.6 μmol h−1) under 1 sun illumination (100 mW cm−2) at zero bias (0 V vs. Pt). The enhancement is attributed to the improved EET of the G/CNT biofilm due to two factors: (1) the large surface area of graphene sheets enables more bacterial cells to adhere onto the surface of the anode, and (2) the incorporation of CNTs into the G-biofilm also improves the conductivity of the biofilm, facilitating direct electron transfer between Shewanella oneidensis and the electrode. This successful demonstration points towards the possibility of further enhancing the H2 performance of hybrid devices through the employment of MFC anodes with higher EET.

G. Bhowmick, E. Kibena‐Põldsepp, L. Matisen et al.

Sustainable Energy & Fuels • 2019

Metal phthalocyanine (CoPc and FePc) modified MWCNT or CDC materials were explored as superior cathode catalysts for MFC technology.

Xue Ting, Qin Xian-sheng, Zhang Shunqi et al.

Journal of Mechanical Engineering • 2020

: Vibration suppression has been a problem needs to be overcome for large-scale flexible structures in the aerospace environment . High elastic modulus, low density advantages of carbon nanotube (CNT) and large actuation forces and flexibility of micro-fiber composite (MFC) make the CNT gradient-reinforced fiber piezoelectric smart structure particularly suitable for aerospace high drop temperature environment.Based on the first order shear deformation and large rotation theory with six parameters, the nonlinear finite element modeling and analysis of the carbon nanotube-reinforced gradient composite plate with MFCs is meaningful.The geometrically nonlinear finite element model is developed for two different kinds of MFC, namely MFC-d31 and MFC-d33.First, the accuracy of the model is validated by experiment results of a reinforcement direction, different control modes make a big difference in the torsion control of the plate and shell. The simulation analysis of piezoelectric smart thin-shell structure based on large rotation theory with six parameters has great application value for shape control and vibration suppression of large flexible components in the aerospace field.

A. O. Sirajudeen, M. Annuar, S. Ibrahim

Chemical Engineering Communications • 2025

Abstract The performance of a microbial fuel cell (MFC) was investigated using a carbon nanotube (CNT)-composited blend of medium-chain-length polyhydroxyalkanoates-co-polycaprolactone (PHA-co-PCL) as a surface coating on the anode electrode. A 1:1 (w/w) blend of PHA and PCL resulted in a material with enhanced thermal properties and efficient bacterial colonization on the anode surface. When composited with CNTs, this blend significantly improved electrochemical performance and reduced overall internal resistance by 81%. The blend composite anode demonstrated superior longevity and stability in generating maximum voltage, outperforming the control anode. The power and current densities, measured at 354 mW/m2 and 768 mA/m2 respectively, were 3.2 and 1.8 times higher than the control anode. Additionally, the blend composite resisted (bio)degradation even after 60 days of MFC operation.

Sophia S. Y. Chan, Shao‐Xiang Go, M. P. Meivita et al.

Materials Advances • 2022

A combined alternating current pulse carbon nanotube platform that can enhance cancer cell-specific thermal ablation via Joule heating.

Yuyang Wang, Guangxu Hu, Dayu Zheng et al.

Coatings • 2023

Microbial fuel cell (MFC) technology can potentially recover bioelectricity from wastewater. However, its practical applications have been limited because of its low power density and since the energy generated from an MFC cannot be stored. In this study, manganese dioxide (MnO2) coupled with carbon nanotubes (CNT) was chosen to in situ modify carbon felt (CF) as a capacitive bioanode (CF/CNT/MnO2) to improve the power generation and energy storage of MFCs. The maximum power density of the MFC with the MnO2-CNT-modified bioanode reached 3471.6 mW m3, which was 1.96 times higher than that of the CF/CNT anode (1772.6 mW m−3). During the experiment of charging for 30 min and discharging for 30 min, the MFC with a capacitive bioanode had a total charge of 8777.1 C m−2, 2.74 times higher than that of the CF/CNT anode. The excellent electricity-producing and energy storage performance of the MFC equipped with the CF/CNT/MnO2 anode is attributed to the composite materials, which can be due to their better biocompatibility, large capacitance, and high specific surface area. This study provides a new way to improve the performance of electricity generation and energy storage of MFCs.

Tiago Amarante, T. H. R. Cunha, Claudio Laudares et al.

Beilstein Journal of Nanotechnology • 2023

In this work, a conductive ink based on microfibrillated cellulose (MFC) and multiwalled carbon nanotubes (MWCNTs) was used to produce transducers for rapid liquid identification. The transducers are simple resistive devices that can be easily fabricated by scalable printing techniques. We monitored the electrical response due to the interaction between a given liquid with the carbon nanotube–cellulose film over time. Using principal component analysis of the electrical response, we were able to extract robust data to differentiate between the liquids. We show that the proposed liquid sensor can classify different liquids, including organic solvents (acetone, chloroform, and different alcohols) and is also able to differentiate low concentrations of glycerin in water (10–100 ppm). We have also investigated the influence of two important properties of the liquids, namely dielectric constant and vapor pressure, on the transduction of the MFC-MWCNT sensors. These results were corroborated by independent heat flow measurements (thermogravimetric analysis). The proposed MFC-MWCNT sensor platform may help paving the way to rapid, inexpensive, and robust liquid analysis and identification.

Nasser A. M. Barakat, S. Gamal, Hak Yong Kim et al.

Frontiers in Chemistry • 2023

Microbial fuel cells (MFCs) offer a dual solution of generating electrical energy from organic pollutants-laden wastewater while treating it. This study focuses on enhancing MFC performance through innovative electrode design. Three-dimensional (3D) anodes, created from corncobs and mango seeds via controlled graphitization, achieved remarkable power densities. The newly developed electrode configurations were evaluated within sewage wastewater-driven MFCs without the introduction of external microorganisms or prior treatment of the wastewater. At 1,000°C and 1,100°C graphitization temperatures, corncob and mango seed anodes produced 1,963 and 2,171 mW/m2, respectively, nearly 20 times higher than conventional carbon cloth and paper anodes. An advanced cathode composed of an activated carbon-carbon nanotube composite was introduced, rivaling expensive platinum-based cathodes. By optimizing the thermal treatment temperature and carbon nanotube content of the proposed cathode, comparable or superior performance to standard Pt/C commercial cathodes was achieved. Specifically, MFCs assembled with corncob anode with the proposed and standard Pt/C cathodes reached power densities of 1,963.1 and 2,178.6 mW/m2, respectively. Similarly, when utilizing graphitized mango seeds at 1,100°C, power densities of 2,171 and 2,151 mW/m2 were achieved for the new and standard cathodes, respectively. Furthermore, in continuous operation with a flow rate of 2 L/h, impressive chemical oxygen demand (COD) removal rates of 77% and 85% were achieved with corncob and mango seed anodes, respectively. This work highlights the significance of electrode design for enhancing MFC efficiency in electricity generation and wastewater treatment.

Na Zhao, Zhaokun Ma, Huaihe Song et al.

Energy Technology • 2018

Abstract Carbon nanotube forest (CNTFs) is grown vertically on the surface of highly conductive mesophase pitch carbon fibers (Pitch‐CFs) in the chemical vapor deposition method. Then the CNTFs‐modified CFs (CNTFs‐Pitch‐CF) as an anode material is assembled into the single chamber microbial fuel cells (MFCs). Interaction between electricigens and carbon nanotubes (CNTs) is investigated. The toxicity of the CNTs can make electricigens expend energy or electrons to produce exopolysaccharid (EPS) as much as possible. Accordingly, this leads to low voltage and the long start up time for the CNTFs‐Pitch‐CF anode in the early period. When the activity of electricigens with the EPS reaches a stable state over time, the output voltage rises rapidly and the maximum power density of the CNTFs‐Pitch‐CF‐equiped MFC is increased to 1112 mW/m 2 , which is approximately 1.55‐fold higher than Pitch‐CF‐equiped MFC. And the CNTFs‐Pitch‐CF‐equiped MFC can keep high electricity generation performance of MFCs for a long time, which is 75 % larger than the Pitch‐CF‐equiped MFC. This method of the CNTFs modifying the CFs provides a new idea for increasing the electricity generation performance of the MFCs.

Ashish Yadav, Nishith Verma

Graphene-based 3D Macrostructures for Clean Energy and Environmental Applications • 2021

Like conventional fuel cells, microbial fuel cells (MFCs) offer an exciting new avenue for generating clean and sustainable electrical energy directly from wastewater and other organic wastes. In recent years, 3D graphene-based macrostructures (GBMs) have been explored as both anode and cathode materials in MFCs to enhance their application potential. 3D GBMs offer an exciting prospect towards application in MFCs owing to their high surface area, biocompatibility, electrical conductivity and chemical stability, thereby leading to an enhanced power generation. This area of research, therefore, provides tremendous opportunities to address the basic challenges of MFCs pertaining to scale-up, commercialization and low power generation in addition to providing alternatives to conventionally used expensive electrodes. The current chapter summarizes the applications of 3D GBMs in MFCs, present their current developmental status, and discuss the key scientific and technological challenges in using them to improve the performance of MFCs.

Okan Avcı, Yudum Tepeli Büyüksünetçi, Emre Erden et al.

New Journal of Chemistry • 2021

A Pseudomonas fragi ( P. fragi ) and graphene–gold hybrid nanomaterial included a carbon felt electrode (graphene–Au/CFE) bioanode was developed and optimized.

Justine E. Mink, Ramy M. Qaisi, Muhammad M. Hussain

Energy Technology • 2013

Abstract Microbial fuel cells harvest electrical energy produced by bacteria during the natural decomposition of organic matter. We report a micrometer‐sized microbial fuel cell that is able to generate nanowatt‐scale power from microliters of liquids. The sustainable design is comprised of a graphene anode, an air cathode, and a polymer‐based substrate platform for flexibility. The graphene layer was grown on a nickel thin film by using chemical vapor deposition at atmospheric pressure. Our demonstration provides a low‐cost option to generate useful power for lab‐on‐chip applications and could be promising to rapidly screen and scale up microbial fuel cells for water purification without consuming excessive power (unlike other water treatment technologies).

Raul-Cristian Roman, Radu-Emil Precup, E. Petriu et al.

Studies in Informatics and Control • 2023

: The purpose of this paper is to propose a novel controller that is based on a combination of two data-driven algorithms, namely the Fictitious Reference Iterative Tuning (FRIT) algorithm and the Model-Free Adaptive Control (MFC) algorithm while considering a particular form of MFC, that is the intelligent proportional-integral-derivative (iPID) controller. The main advantage of this combination is that the FRIT algorithm optimally tunes the parameters of the iPID controller by solving an optimization problem based on a metaheuristic African Vultures Optimization Algorithm (AVOA). The novel controller, referred to as the FRIT-iPID controller, is validated experimentally on a three-degree-of-freedom tower crane system laboratory equipment in the context of controlling the cart position, the arm angular position and the payload position for this system.

Shu Deng, Yahong Zhang, Yajun Luo et al.

International Journal of Applied Electromagnetics and Mechanics • 2025

For plate structures undergoing time-varying motion, deformation and vibration occur simultaneously due to the inertia force induced by accelerations. The difference in deformation magnitude and vibration amplitude significantly affects the accuracy and safety of the structures. Traditional control methods cannot suppress deformation and vibration synchronously, therefore, an integrated active control strategy has been developed to address this issue. The dynamic equation for the plate partially covered with Macro Fiber Composite (MFC) actuators is established. The system presents strong nonlinearity because four coupling factors are involved, such as rigid body motion coupling, deformation coupling, rigid body motion and deformation coupling, as well as electro-mechanical coupling. To simultaneously mitigate deformation and vibration, the Sliding Mode Control (SMC) algorithm is optimized using the Particle Swarm Optimization (PSO) algorithm, enabling integrated active control for the plate subjected to time-varying inertia forces. The effectiveness of the developed PSO-SMC algorithm is validated by simulations.

Alexander Vidal, Samy Wu Fung, Stanley Osher et al.

2025 American Control Conference (ACC) • 2024

Mean-field control (MFC) problems aim to find the optimal policy to control massive populations of interacting agents. These problems are crucial in areas such as economics, physics, and biology. We consider the non-local setting, where the interactions between agents are governed by a suitable kernel. For $N$ agents, the interaction cost has $\mathcal{O}(N^2)$ complexity, which can be prohibitively slow to evaluate and differentiate when $N$ is large. To this end, we propose an efficient primal-dual algorithm that utilizes basis expansions of the kernels. The basis expansions reduce the cost of computing the interactions, while the primal-dual methodology decouples the agents at the expense of solving for a moderate number of dual variables. We also demonstrate that our approach can further be structured in a multi-resolution manner, where we estimate optimal dual variables using a moderate $N$ and solve decoupled trajectory optimization problems for large $N$. We illustrate the effectiveness of our method on an optimal control of 5000 interacting quadrotors.

T. Silva, Celia Hameury, Giovanni Ferrari et al.

Volume 4B: Dynamics, Vibration, and Control • 2014

Abstract Active vibration control of a free-edge rectangular sandwich plate is proposed and tested. The experimental setup consists of a honeycomb panel having a carbon-fiber reinforced polymer (CFRP) outer skins and a polymer-paper core, subjected to an orthogonal disturbance, due to an electrodynamics exciter and controlled by Macro Fibre Composite (MFC) actuators and sensors. MFC parches consist of rectangular piezoceramic rods sandwiched between layers of adhesive, electrodes and polyamide film. The MFC actuators and sensors are controlled by a programmable digital dSPACE® controller board. The control algorithm proposed in this paper is based on the Positive Position Feedback (PPF) technique and is successfully applied with different combinations of inputs/outputs (Single Input Single Output, MultiSISO, Multi Input Multi Output) in order to control the first four normal modes. The control appears to be robust and efficient in reducing vibration in linear (small amplitude) and nonlinear (large amplitude) vibrations regimes, although the structure under investigation exhibits a relativity high modal density, i.e., four resonances in a range of about 100 Hz. The control strategy allows to effectively control each resonance both individually or simultaneously.

S. Nadjafi, G. G. Amiri, A. Hosseinzadeh et al.

SHILAP Revista de lepidopterología • 2020

In this paper, a computationally simple approach for damage localization and quantification in beam-like structures is proposed. This method is based on using modal flexibility curvature (MFC) and particle swarm optimization (PSO) algorithm. Analytical studies in the literature have shown that changes in the modal flexibility curvature can be considered as a sensitive and suitable criterion for identifying damage in the beam-like structures. Modal flexibility curvature can be calculated utilizing central difference approximation, based on entries of the modal flexibility matrix. The PSO algorithm, as a powerful optimization tool, is used to minimize the error function which is formulated as an error function between the measured modal flexibility curvatures of the damaged structure and those calculated from the analytical structure. To demonstrate the efficiency of the method, two beam-like structures under different damage scenarios are studied. In addition, the robustness of presented method is investigated when only the first several modal data are available. It is observed that the proposed approach is able to localize and quantify various damage cases only by a few lower vibrational modes and also, it is low-sensitive to measurement noise.

Qidong Li, Hehua Ju, Pengfei Xiao

IOP Conference Series: Materials Science and Engineering • 2020

In order to solve the problem of 6R manipulator kinematics, this paper analyzes the inverse kinematics solution and optimizes the solution process of forward kinematics. Aimed to the structural characteristics of the manipulator, this paper first introduces the concept of the natural invariants, establishes the Denavit-Hatenber (D-H) model based on the natural invariants and proposes a new iterative algorithm for manipulator forward kinematics. Then, the inverse kinematics based on the natural invariants is proposed, which is divided into the position inverse solution and the inverse attitude solution, and the analytical solution is obtained by analyzing the singularity of the solution. Finally, the visual simulation model is built with MFC and Coin4D. The simulation results show that the proposed forward and inverse kinematics method of the six-degree-of-freedom manipulator has small error and high efficiency, and the accuracy and real-time performance of the algorithm are verified.

Xuejing Li, Yajuan Qin, Huachun Zhou et al.

Wireless Communications and Mobile Computing • 2020

With the increasing popularity of terminals and applications, the corresponding requirements of services have been growing significantly. In order to improve the quality of services in resource restrained user devices and reduce the large latency of service migration caused by long distance in cloud computing, mobile fog computing (MFC) is presented to provide supplementary resources by adding a fog layer with several servers near user devices. Focusing on cloud-aware MFC networks with multiple servers, we formulate a problem with the optimization objective to improve the quality of service, relieve the restrained resource of user device, and balance the workload of participant server. In consideration of the data size of remaining task, the power consumption of user device, and the appended workload of participant server, this paper designs a machine learning-based algorithm which aims to generate intelligent adaptive strategies related with load balancing of collaborative servers and dynamic scheduling of sequential tasks. Based on the proposed algorithm and software-defined networking technology, the tasks can be executed cooperatively by the user device and the servers in the MFC network. Besides, we conducted some experiments to verify the algorithm effectiveness under different numerical parameters including task arrival rate, avaliable server workload, and wireless channel condition. The simulation results show that the proposed intelligent adaptive algorithm achieves a superior performance in terms of latency and power consumption compared to candidate algorithms.

Minmin Wang, Aimin An

2020 Chinese Automation Congress (CAC) • 2020

Microbial fuel cell (MFC) has serious nonlinearity and external disturbances when operating. In order to keep the ideal output of MFC under different load disturbances, an intelligent optimization control method based on BP neural network PID(BP-NN PID) is proposed. This method uses self-learning ability to tune the parameter of the PID controller. In addition, the online real-time control of the BP-NN algorithm shows the ability of the BP-NN to handle nonlinear systems. The simulation experiment finally shows that compared with traditional PID and single neuron PID, the BP-NN PID algorithm has good dynamic response, steady-state accuracy, adaptive ability, and strong robustness, which can make the output voltage of MFC meet the requirements.

Hao Long, Arash Khalatbarisoltani, Xiaosong Hu

2022 IEEE Vehicle Power and Propulsion Conference (VPPC) • 2022

Modular fuel cell (MFC) systems, which have multiple fuel cell stacks that work independently, are becoming increasingly popular in heavy-duty transportation because they are more efficient, reliable, and easy to use (plug-and-play). This paper aims at developing a lifespan-conscious energy management strategy (EMS) for a heavy-duty modular fuel cell vehicle (MFCV) to enhance the economic performance during the whole life cycle of its components. In this work, the main decision-making problem is broken down into two more minor problems that are solved simultaneously with a decentralized optimization algorithm called the auxiliary problem principle (APP). A comparison is made between the proposed EMS and a well-known central algorithm called sequential quadratic programming (SQP). The simulation results show that a decentralized algorithm can significantly speed up convergence while raising the economic cost a little more than a centralized algorithm.

M. Gharib

Reports in Mechanical Engineering • 2020

Received October 15, 2020 Revised November 25, 2020 Accepted December 5, 2020 This paper suggests a practical approach for the development of a stable robot controller using the Quantitative Feedback Principle (QFT). Robot manipulators have a multivariable nonlinear transfer function, the implementation of the QFT method includes, first the conversion of their nonlinear plant into a group of linear and uncertain plant set, and then an ideal robust controller for each set has been designed. To demonstrate the effectiveness of our algorithm, we show the implementation of the two degrees of freedom manipulator. In the approach provided, the controller has been designed directly by specifying and optimizing the transfer function coefficients using a genetic algorithm. The consistency and limitations of the method are considered to be the restrictions of the problem in the optimization process. System stability and tracking problem are perceived to be the limitations of the system in the optimization process. Non-linear simulations on the tracking problem are carried out and the results illustrate the performance of the controllers. Finally, the controller constructed based on the QFT approach is compared with the TFC and MFC (Fuzzy) controllers and it is shown that the QFT methodology indicates a controller that has increased control efficiency.

Hassan Mehmood, T. Zafar, Khurram Kamal et al.

2024 International Conference on Robotics and Automation in Industry (ICRAI) • 2024

Microbial Fuel Cells (MFCs) are environment-friendly devices to generate energy through microbial metabolism of the chemical energy of organic compounds. Few of the critical challenges of implementing MFCs are their low power density, high internal resistance, and poor electron transport. These factors are major drawbacks to the MFCs efficiency and ability to scale up MFCs. The proposed work aims to enhance the MFC performance by optimizing the proportions of key operational parameters to overcome the implementation challenges. These parameters include Substrate Concentration $(S)$, Anodophilic Biomass $(x_{a})$, Methanogenic Biomass $(x_{m})$, and Oxidized Mediator $(M_{ox})$. The parameters are optimized using a Gradient Based Optimization (GBO). During the optimization process, it was imperative to establish a sound mathematical model that predicted MFC's biological and physical behavior. With the implementation of the GBO algorithm, the output current is enhanced by 8. 89 percent. The results shows that promising future of the proposed method.

Jinhua Jiang, Zhiyuan Gao, Hesheng Zhang et al.

Journal of Intelligent Material Systems and Structures • 2024

To reduce vibration-induced fatigue fractures of aero-engine blades, an active vibration control scheme for aero-engine blade has been developed proposed. In this paper, the Macro Fiber Composite (MFC) are used as actuators and sensors to suppress the vibration of the blade, but the position of the actuators and sensors has a great influence on the effectiveness of the blade vibration suppression. To achieve optimize suppress effect, the objective criterion for position optimization was proposed to be the absolute value normalized superposition of the strain of the first few natural frequency modes of the blade. First, a finite element analysis was conducted on the blade model. Then, the positions of the actuators and sensors were determined by using the differential evolution algorithm for optimization. The blade model with three layout strategies was constructed in ADAMS, and the ADAMS-Simulink joint simulation platform was constructed. Finally, the comparison of actuator and sensor effects with three position layout strategies is completed, the layout optimization strategy proposed in this paper achieves more significant vibration suppression with less control force was verified though the feedforward control experiments, and the effective of the proposed strategies are verified on the experimental platform for blade active vibration control.

Chenlong Wang, Baolong Zhu, Fengying Ma et al.

Electronics • 2024

The microbial fuel cell (MFC) is a renewable energy technology that utilizes the oxidative decomposition processes of anaerobic microorganisms to convert the chemical energy in organic matter, such as wastewater, sediments, or other biomass, into electrical power. This technology is not only applicable to wastewater treatment but can also be used for resource recovery from various organic wastes. The MFC usually requires an external controller that allows it to operate under controlled conditions to obtain a stable output voltage. Therefore, the application of a PID controller to the MFC is proposed in this paper. The design phase for this controller involves the identification of three parameters. Although the particle swarm optimization (PSO) algorithm is an advanced optimization algorithm based on swarm intelligence, it suffers from issues such as unreasonable population initialization and slow convergence speed. Therefore, this paper proposes an improved particle swarm algorithm based on the Golden Sine Strategy (GSCPSO). Using Circle chaotic mapping to make the distribution of the initial population more uniform, and then using the Golden Sine Strategy to improve the position update formula, not only improves the convergence speed of the population but also enhances convergence precision. The GSCPSO algorithm is applied to execute the described design process. The results of the simulation show that the designed control method exhibits smaller steady-state error, overshoot, and chattering compared with sliding-mode control (SMC), backstepping control, fuzzy SMC (FSMC), PSO-PID, and CPSO-PID.

L. Fan

International Journal of Electrochemical Science • 2021

Microbial fuel cell (MFC) has attracted more and more attention as a kind of efficient and green power source. Due to its own complexity, the precise control of MFC is still difficult to achieve. The output voltage of MFC has large overshoot and shock under traditional PID control, and it is difficult to adapt to the changes in operating conditions. So, a genetic algorithm optimized fuzzy PID control is proposed to improve the controller effect and realize the constant voltage output control of the MFC. Simulation results show that compared with the traditional PID, the genetic algorithm optimized PID, and the fuzzy tuning PID, the genetic algorithm optimized fuzzy PID control shows smaller overshoot, better stability and stronger anti-interference ability. Optimizing the conventional PID through fuzzy logic and genetic algorithm is a simple, easy, low-cost but effective method to solve the problems of unstable power generation and poor anti-interference ability of MFC system.

Chong Li, Liang Shen, Jiang Shao et al.

Polymers • 2023

In order to improve the vibration suppression effect of the flexible beam system, active control based on soft piezoelectric macro-fiber composites (MFCs) consisting of polyimide (PI) sheet and lead zirconate titanate (PZT) is used to reduce the vibration. The vibration control system is composed of a flexible beam, a sensing piezoelectric MFC plate, and an actuated piezoelectric MFC plate. The dynamic coupling model of the flexible beam system is established according to the theory of structural mechanics and the piezoelectric stress equation. A linear quadratic optimal controller (LQR) is designed based on the optimal control theory. An optimization method, designed based on a differential evolution algorithm, is utilized for the selection of weighted matrix Q. Additionally, according to theoretical research, an experimental platform is built, and vibration active control experiments are carried out on piezoelectric flexible beams under conditions of instantaneous disturbance and continuous disturbance. The results show that the vibration of flexible beams is effectively suppressed under different disturbances. The amplitudes of the piezoelectric flexible beams are reduced by 94.4% and 65.4% under the conditions of instantaneous and continuous disturbances with LQR control.

Hegazy Rezk, A. Olabi, M. Abdelkareem et al.

Sustainability • 2023

Microbial fuel cells convert the chemical energy conserved in organic matter in wastewater directly to electrical energy through living microorganisms. These devices are environmentally friendly thanks to their ability to simultaneously produce electrical energy and wastewater treatment. The output power of the yeast microbial fuel cell (YMFC) depends mainly on glucose concentration and glucose/yeast ratio. Thus, the paper aims to boost the power of YMFC by identifying the best values of glucose concentration and glucose/yeast ratio. The suggested approach comprises fuzzy modelling and optimization. Fuzzy is used to build the model based on the measured data. In the optimization stage, the marine predators’ algorithm (MPA) is applied to identify the best glucose concentration values and glucose/yeast ratio corresponding to the maximum output power of YMFC. The results revealed the superiority of the combination of fuzzy and MPA compared with the response surface methodology (RSM) approach. Regarding the modelling accuracy, the coefficient of determination increased by 13.32% and 8.37%, respectively, for without methylene blue and with methylene blue compared with RSM. The integration between fuzzy and MPA succeeded in maximizing the output power from YMFC. Without MB, the power density increased by 25% and 29.3%, respectively, compared with measured data and RSM. In addition, with MB, the power density increased by 22.4% and 26%, compared with measured data and RSM.

Tongxin Xu, Ruichen Yu, Zhiyuan Gao et al.

2024 43rd Chinese Control Conference (CCC) • 2024

Sensors and actuators placements play an important role in the control performance of an active vibration control system for piezoelectric smart aero-engine blades. Incorrect placement of sensors and actuators may lead to instability in the control system. This paper proposes optimal placement methods based on the Particle Swarm Optimization (PSO) algorithm for actuators and sensors. Firstly, three sensors and actuators placement optimization schemes are proposed based on the modal analysis and transient analysis results of ANSYS. These schemes include the superposition of non-absolute normalized modal strains, the energy criterion for transient analysis, and the superposition of absolute normalized modal strains. Secondly, it is ensured that the placements of the MFC piezoelectric elements are optimized based on the Particle Swarm Optimization (PSO) Algorithm and Differential Evolution (DE) Algorithm within the boundary constraints. Finally, the convergence of the fitness function based on the PSO algorithm and the DE algorithm as well as the three schemes are comparatively analyzed and the optimal placement of the MFC is found. Simulation results show that the last scheme optimized based on the PSO algorithm has better convergence effect and can obtain the optimal placements of sensors and actuators.