Dynamic Switching Research Articles

In-Situ Gas Permeation-Driven Ionic Current Rectification of Heterogeneously Charged Nanopore Arrays.

Ionic diodes provide ionic current rectification (ICR), which is useful for micro-/nanofluidic devices for ionic current-mediated applications. However, the modulation of ICR is not fully developed, and current challenges include limited active control and localized modulation for further multiplexing of micro-/nanofluidic ionic diodes. Herein, a microfluidic device integrated with particle-assembly-based ionic diodes (PAIDs) and a gas-flow channel above them is presented. Exploiting in-situ gas permeation through a polymeric film, precise control over the physiochemical conditions of the nanopores within the PAIDs, leading to the modulation of ICR is demonstrated. The investigation not only characterizes the rectification properties of the PAIDs but also unveils their capacitor-like behavior and the ability to actively modulate ICR using various gas flows. Furthermore, the reversible modulation of ICR through dynamic switching of gas-dissolved solutions, enabling ion-signal amplification is showcased. This pioneering approach of in situ gas-permeation offers programmable manipulation of ion transport along PAIDs, thereby positioning ionic diodes as versatile nanofluidic components. Looking ahead, the development of multiplexed PAIDs in an addressable manner on a chip holds promise for practical applications across diverse fields, including ion signaling, ion-based logic, chemical reactors, and (bio)chemical sensing.

An Exo III-powered closed-loop DNA circuit architecture for biosensing/imaging.

With their regulated Boolean logic operations in vitro and in vivo, DNA logic circuits have shown great promise for target recognition and disease diagnosis. However, significant obstacles must be overcome to improve their operational efficiency and broaden their range of applications. In this study, we propose an Exo III-powered closed-loop DNA circuit (ECDC) architecture that integrates four highly efficient AND logic gates. The ECDC utilizes Exo III as the sole enzyme-activated actuator, simplifying the circuit design and ensuring optimal performance. Moreover, the use of Exo III enables a self-feedback (autocatalytic) mechanism in the dynamic switching between AND logic gates within this circulating logic circuit. After validating the signal flow and examining the impact of each AND logic gate on the regulation of the circuit, we demonstrate the intelligent determination of miR-21 using the carefully designed ECDC architecturein vitro. The proposed ECDC exhibits a linear detection range for miR-21 from 0 to 300 nM, with a limit of detection (LOD) of approximately 0.01 nM, surpassing most reported methods. It also shows excellent selectivity for miR-21 detection and holds potential for identifying and imaging live cancer cells. This study presents a practical and efficient strategy for monitoring various nucleic acid-based biomarkersin vitro and in vivo through specific sequence modifications, offering significant potential for early cancer diagnosis, bioanalysis, and prognostic clinical applications.

Dynamic frequency switching of a bandstop reconfigurable frequency selective surface with PIN diodes for C/X and Ku-band shielding applications

This paper presents a reconfigurable bandstop frequency selective surface (R-FSS) design capable of switching across C, X and Ku-bands. The electronic switching mechanism is achieved in real-time through PIN diodes. The combination of rectangular loops is selected as unit-cell and PIN diodes are strategically placed to dynamically adjust the bandstop region. The device operates in three distinct modes corresponding to the activation status of the PIN-diodes. For TE polarization, Mode 1 encompasses the Ku-bandstop (12.64–14.75 GHz), Mode 2 corresponds to the C/X-bandstop (6.62–11.28 GHz), and Mode 3 involves the X-bandstop (9.82–11.63 GHz), whereas X-bandstop characteristic is observed for TM polarization (9.054–––11.29 GHz). In TE polarization, each configuration is defined by specific equivalent circuit models, featuring an inductance in parallel with series L-C resonant circuit, an L-C resonant circuit in parallel with the inductance, and two L-C resonant circuits in parallel, respectively. Additionally, for TM polarization, the configuration incorporates two parallel L-C resonant circuits. A prototype of the proposed R-FSS is fabricated and measured. The results demonstrated effective switching operation across the C, X and Ku-band stopbands, depending on the biasing of the PIN diodes. The experimental outcomes are consistent with the simulation results, affirming the compatibility and functionality of the proposed R-FSS design.

Aptamer-Based DNA Allosteric Switch for Regulation of Protein Activity.

Allostery is a fundamental way to regulate the function of biomolecules playing crucial roles in cell metabolism and proliferation and is deemed the second secret of life. Given the limited understanding of the structure of natural allosteric molecules, the development of artificial allosteric molecules brings a huge opportunity to transform the allosteric mechanism into practical applications. In this study, the concept of bionics is introduced into the design of artificial allosteric molecules and an allosteric DNA switch with an activity site and an allosteric site based on two aptamers for selective inhibition of thrombin activity. Compared with the single aptamer, the allosteric switch possesses a significantly enhanced inhibition ability, which can be precisely regulated by converting the switch states. Moreover, the dynamic allosteric switch is further subjected to the control of the DNA threshold circuit for realizing automatic concentration determination and activity inhibition of thrombin. These compelling results confirm that this allosteric switch equipped with self-sensing and information-processing modules puts a new slant on the research of allosteric mechanisms and further application of allosteric tactics in chemical and biomedical fields.

Efficient aerodynamic optimization of turbine blade profiles: an integrated approach with novel HDSPSO algorithm

PurposeThis paper delves into the aerodynamic optimization of a single-stage axial turbine employed in aero-engines.Design/methodology/approachAn efficient integrated design optimization approach tailored for turbine blade profiles is proposed. The approach combines a novel hierarchical dynamic switching PSO (HDSPSO) algorithm with a parametric modeling technique of turbine blades and high-fidelity Computational Fluid Dynamics (CFD) simulation analysis. The proposed HDSPSO algorithm introduces significant enhancements to the original PSO in three pivotal aspects: adaptive acceleration coefficients, distance-based dynamic neighborhood, and a switchable learning mechanism. The core idea behind these improvements is to incorporate the evolutionary state, strengthen interactions within the swarm, enrich update strategies for particles, and effectively prevent premature convergence while enhancing global search capability.FindingsMathematical experiments are conducted to compare the performance of HDSPSO with three other representative PSO variants. The results demonstrate that HDSPSO is a competitive intelligent algorithm with significant global search capabilities and rapid convergence speed. Subsequently, the HDSPSO-based integrated design optimization approach is applied to optimize the turbine blade profiles. The optimized turbine blades have a more uniform thickness distribution, an enhanced loading distribution, and a better flow condition. Importantly, these optimizations lead to a remarkable improvement in aerodynamic performance under both design and non-design working conditions.Originality/valueThese findings highlight the effectiveness and advancement of the HDSPSO-based integrated design optimization approach for turbine blade profiles in enhancing the overall aerodynamic performance. Furthermore, it confirms the great prospects of the innovative HDSPSO algorithm in tackling challenging tasks in practical engineering applications.

Modeling defect-level switching for nonlinear and hysteretic electronic devices

Previously, we demonstrated hysteretic and persistent changes of resistivity in two-terminal electronic devices based on charge trapping and detrapping at immobile metastable defects [Yin et al., Phys. Rev. Appl. 15, 014014 (2021)]; we termed these defect-level switching (DLS) devices. DLS devices feature all-electronic resistive switching and thus are volatile because of the “voltage-time” dilemma. However, the dynamics of volatile resistive switches may be valuable for emerging applications such as selectors in crosspoint memory and neuromorphic computing concepts. To design circuits using these volatile resistive switches, accurate modeling is essential. In this work, we develop an accurate and analytical model to describe the switching in DLS devices, based on the established theories of point defect metastability in Cu(In,Ga)Se2 (CIGS) and II–VI semiconductors. The analytical nature of our model allows for time-efficient simulations of dynamical behavior of DLS devices. We model the time durations of SET and RESET programming pulses, which can be exponentially shortened with respect to the pulse amplitude. We also demonstrate the concept of inverse design: given desired resistance states, the width and amplitude of the programming signal can be chosen accordingly.

Construction of wear-resistant visible-infrared-compatible camouflage film and its spectral control mechanisms

The ceaseless advancement of modern surveillance technologies has underscored an urgent need for the development of stealth materials with multi-spectral camouflage capabilities. Spectral selectivity, achieved through the design of micro-nano structures, can effectively manage conflicting requirements across various light regimes. Nonetheless, creating visible-Infrared (IR)-compatible devices that are both structurally simple and suitable for use as optic windows or coatings remains a formidable challenge. Here, we report a MgF2/Ag/MgF2 visible-IR-compatible film based on Monte Carlo optimization which has high visible transparency, low IR emissivity, ideal wear-resistance, and dynamic tunability. The designed film can maintain high transparency (∼80%) to ensure replication of background without sacrificing low IR emissivity (∼0.3). Notably, the film maintains its spectral selectivity across a wide range of angles and is endowed with the capability for dynamic modality switching between “heating” and “cooling” states under electrical actuation with good stability under long-term service and harsh environment. This film has a maximum temperature characteristic modulation range of 3.5 °C, demonstrating excellent performance in intelligent thermal management. It is also compatible with electrochromic camouflage devices enabling it to cover a broader spectrum of reconnaissance without contradictions. It is an effective way to fulfill the camouflage requirements and smart thermal management across diverse environments, and possesses great potential for scalability and flexibility.

Cholinergic modulation supports dynamic switching of resting state networks through selective DMN suppression.

Brain activity during the resting state is widely used to examine brain organization, cognition and alterations in disease states. While it is known that neuromodulation and the state of alertness impact resting-state activity, neural mechanisms behind such modulation of resting-state activity are unknown. In this work, we used a computational model to demonstrate that change in excitability and recurrent connections, due to cholinergic modulation, impacts resting-state activity. The results of such modulation in the model match closely with experimental work on direct cholinergic modulation of Default Mode Network (DMN) in rodents. We further extended our study to the human connectome derived from diffusion-weighted MRI. In human resting-state simulations, an increase in cholinergic input resulted in a brain-wide reduction of functional connectivity. Furthermore, selective cholinergic modulation of DMN closely captured experimentally observed transitions between the baseline resting state and states with suppressed DMN fluctuations associated with attention to external tasks. Our study thus provides insight into potential neural mechanisms for the effects of cholinergic neuromodulation on resting-state activity and its dynamics.

Optimization of heating temperature uniformity for multi-microwave source group based on dynamic switching topology

Aiming at the mutual coupling of multiple physical fields in the microwave heating process and the generation of thermal runaway phenomenon, in this paper, a cooperative variable power heating strategy with multi-microwave source clusters under dynamic switching topology is proposed in order to improve the temperature uniformity. Firstly, an algebraic graph theory is used to establish a communication topology for complete information transfer, which is used to construct a distributed structure among multiple microwave source intelligences. Secondly, the dynamic topology switching algorithm under event triggering is introduced, and the real-time temperature distribution of the heated materials is considered to achieve the dynamic switching of the topology connection mode between microwave source clusters in order to synchronously coordinate the power consistency output between different clusters. On this basis, a numerical calculation model is constructed to solve the mixed optimization of integer and continuum variables by means of the finite element method. Finally, the effectiveness of the heating strategy to improve temperature uniformity is verified by microwave heating SiC media simulation calculation. The numerical calculation results show that the temperature uniformity indexes are improved by 34.1%–50.4% and 28.1%–55.2% in each horizontal and vertical section for single materials, and by 59.1%–59.7% and 46.5%–63.4% in each horizontal and vertical section for multi-materials, respectively, in comparison with the general heating method. This strategy effectively avoids the residence of hot and cold spots in the material, which in turn optimizes the temperature distribution.

Octopus-Inspired Soft Robot for Slow Drug Release.

Octopus tentacles are equipped with numerous suckers, wherein the muscles contract and expel air, creating a pressure difference. Subsequently, when the muscular tension is released, objects can be securely adhered to. This mechanism has been widely employed in the development of adhesive systems. However, most existing octopus-inspired structures are passive and static, lacking dynamic and controllable adhesive switching capabilities and excellent locomotion performance. Here, we present an octopus-inspired soft robot (OISR). Attracted by the magnetic gradient field, the suction cup structure inside the OISR can generate a strong adsorption force, producing dynamically controllable adsorption and separation in the gastrointestinal (GI) tract. The experimental results show that the OISR has a variety of controllable locomotion behaviors, including quick scrolling and rolling motions, generating fast locomotion responses, rolling over gastric folds, and tumbling and swimming inside liquids. By carrying drugs that are absorbable by GI epithelial cells to target areas, the OISR enables continuous drug delivery at lesions or inflamed regions of the GI tract. This research may be a potential approach for achieving localized slow drug release within the GI tract.

Advancing security and efficiency in MANET using dynamic algorithm switching

Advancing security and efficiency in MANET using dynamic algorithm switching

42‐2: Self‐Scalable UV Blocking Artificial Iris Operated by Radially Controlled Crosslinking Density with Fast Switching Dynamics

In the anatomy of human eye, the role of iris is crucial since it controls the light level entering the eye and enhances the visibility. Here, we propose a soft contact lens type artificial iris actuated by eternal UV (ultra‐violet) light source, self‐regulating its effective aperture size by varying the crosslinking density of bio‐compatible polymer matrix doped with photochromic dye. For its self‐regulating characteristic, we cured HEMA‐based polymer matrix gradually from center to edge. Since the polymer matrix is polymerized by heat, we utilized NIR (near infra‐red) lamp and gradient grayscale patterned photomask for its gradual characteristic. Thereby, the crosslinking density of central position is higher compared to that of peripheral, causing slow switching dynamics. The gradient difference in switching dynamics leads to artificial iris gaining self‐regulation dynamics of effective aperture. The manufactured artificial iris shows advantage in blocking UV light, self‐regulating, and fast switching dynamics. The switching dynamics of artificial iris under bright and dim light adaptation are less than 50 seconds and 120 seconds, showing similar property with human iris.

Flexible Organic Ferroelectric Synaptic Transistors for Wearable Neuromorphic Systems

An organic ferroelectric synaptic transistor (OFST) is an excellent candidate for use as an artificial synapse in wearable neuromorphic systems. In OFSTs, polarization switching is achieved by electric stimuli, leading to the modulation of channel conductance. To develop wearable neuromorphic systems employing OFSTs, it is necessary to effectively emulate biological synaptic functions in the devices by controlling dipole switching dynamics. In this paper, the operating mechanisms for the OFSTs, and the organic ferroelectric materials are first discussed. Recent researches for controlling the polarization switching dynamics to emulate synaptic characteristics, including synaptic plasticity, continuous synaptic weight, low operating voltage, and multifunctional capability, are then reviewed. Lastly, future research directions for achieving bio-realistic OFSTs for practical wearable electronics are proposed.

Distribution of the built-in field extracted from switching dynamics in HfO2-based ferroelectric capacitor

In this work, we proposed a method to extract the distribution of the built-in field (Eb) from the switching dynamics of the TiN/HfZrO/TiN capacitor. The relationship between reversal polarization and the distribution of Eb is established based on the classic inhomogeneous field mechanism model. Both positive and negative write pulses with different amplitudes and durations are applied to obtain the distribution parameters of Eb. The distribution of Eb is fitted by a Gaussian-type distribution, and the mean value and standard deviation are about −0.02 MV/cm and 0.28 MV/cm, respectively. This work provides an effective approach to analyze Eb directly from the electrical measurement and helps optimize the device design from the polarization switching point of view.

Proliferation of unstable states and their impact on stochastic out-of-equilibrium dynamics in two coupled Kerr parametric oscillators.

Networks of nonlinear parametric resonators are promising candidates as Ising machines for annealing and optimization. These many-body out-of-equilibrium systems host complex phase diagrams of coexisting stationary states. The plethora of states manifest via a series of bifurcations, including bifurcations that proliferate purely unstable solutions. Here we demonstrate that the latter take a fundamental role in the stochastic dynamics of the system. Specifically, they determine the switching paths and the switching rates between stable solutions. We demonstrate experimentally the impact of the added unstable states on noise-activated switching dynamics in a network of two coupled parametric resonators.

Mito-Specific Nutri-Hijacker Synergizing Mitochondrial Metabolism and Glycolysis Intervention for Enhanced Antitumor Bioenergetic Therapy.

Metabolic rewiring, a dynamic metabolic phenotype switch, confers that tumors exist and proliferate after fitness (or preadaptation) in harsh environmental conditions. Glycolysis deprivation was considered to be a tumor's metabolic Achilles heel. However, metabolic configuration can flexibly retune the mitochondrial metabolic ability when glycolysis is scared, potentially resulting in more aggressive clones. To address the challenge of mitochondrial reprogramming, an antiglycolytic nanoparticle (GRPP NP) containing a novel mitochondrial-targeted reactive oxygen species (ROS) generator (diIR780) was prepared to hijack glucose and regulate mitochondria, thus completely eliminating tumorigenic energy sources. In this process, GRPP NPs@diIR780 can catalyze endogenous glucose, leading to significantly suppressed glycolysis. Moreover, diIR780 can be released and selectively accumulated around mitochondria to generate toxic ROS. These combined effects, in turn, can hamper mitochondrial metabolism pathways, which are crucial for driving tumor progression. This synchronous intervention strategy enables utter devastation of metabolic rewiring, providing a promising regiment to eradicate tumor lesions without recurrence.

The switching dynamics of self-defocusing nonlinear coupled system with PT-symmetric Scarf II barrier potential

The switching dynamics of self-defocusing nonlinear coupled system with PT-symmetric Scarf II barrier potential

ASYMMETRICAL 7 LEVEL MULTILEVEL INVERTER FOR DYNAMIC LOADS

Asymmetric multilevel inverters (AMLIs) have received great attention in the power industry due to their ability to solve problems caused by power supply in various applications. This report explores the design, analysis and performance of AMLI's heavy-duty equipment. Dynamic loads are characterized by rapid and unpredictable changes in power demand, causing significant outages due to the limitations of traditional inverters in providing efficient power delivery and stability. The AMLI concept takes advantage of the ability to produce multiple voltage levels, providing greater flexibility to adapt to the needs of the load. This study investigates the optimization of modulation techniques to improve the efficiency and response time of the inverter in dynamically changing scenarios. In addition, factors such as harmonic distortion and power quality were also taken into account in the study, and the effect of asymmetric voltage levels on the overall system performance was examined. Simulation results and experimental results show that the effectiveness of AMLI in dynamic switching is good. The results of this study provide great insights into the use of AMLI with electronic devices, showing promise in improving power conversion and safety in real-world applications. Keywords: Asymmetric multilevel inverters (AMLIs), Power industry, Design, Analysis, Performance, Heavy-duty equipment.

Distributed l2−l∞ filtering over wireless sensors based on adaptive event triggering

This paper investigates the design problem of a set of distributed filters. These adaptive event-triggered (AET) filters have the [Formula: see text] property and are suitable for sensor networks characterized by random measurement data loss and dynamic topology switching. In a distributed filtering network, each local filter estimates the system’s state not only relying on the node’s individual information but also using information from neighboring nodes in the network topology. The adaptive event triggering condition is determined by the combination of the latest release data of the filter itself, the estimated value of the current moment, and the latest release data of the neighboring nodes. The event triggering mechanism adopts a threshold adaptive adjustment scheme, which dynamically changes the threshold parameter according to the filtering error under the premise of guaranteeing the filter performance, thus maximally saving the network communication resources. Initially, we used a binary sequence to describe the random loss of sensor measurements, and a Markov chain is used to describe the switching of the filtering network topology. Secondly, a Lyapunov function is created to examine the [Formula: see text] performance index of the filtering error system and investigate its mean square exponential stability. Subsequently, the distributed filter is formulated, and its parameters are determined using the linear matrix inequality approach. Ultimately, the validity of the proposed method is substantiated through numerical illustrations.

Transcription factor activating enhancer-binding protein 2ε (AP2ε) modulates phenotypic plasticity and progression of malignant melanoma

Malignant melanoma, the most aggressive form of skin cancer, is often incurable once metastatic dissemination of cancer cells to distant organs has occurred. We investigated the role of Transcription Factor Activating Enhancer-Binding Protein 2ε (AP2ε) in the progression of metastatic melanoma. Here, we observed that AP2ε is a potent activator of metastasis and newly revealed AP2ε to be an important player in melanoma plasticity. High levels of AP2ε lead to worsened prognosis of melanoma patients. Using a transgenic melanoma mouse model with a specific loss of AP2ε expression, we confirmed the impact of AP2ε to modulate the dynamic switch from a migratory to a proliferative phenotype. AP2ε deficient melanoma cells show a severely reduced migratory potential in vitro and reduced metastatic behavior in vivo. Consistently, we revealed increased activity of AP2ε in quiescent and migratory cells compared to heterogeneously proliferating cells in bioprinted 3D models. In conclusion, these findings disclose a yet-unknown role of AP2ε in maintaining plasticity and migration in malignant melanoma cells.