Topology Design Research Articles

Topological Single-stranded DNA Encoding and Programmable Assembly of Molecular Nanostructures for NIR-II Cancer Theranostics.

Molecular nanotechnology promises to offer privileged access to developing NIR-II materials with precise structural and functional manipulation for transformable theranostic applications. However, the lack of an affordable, yet general, method makes this goal currently inaccessible. By virtue of the intriguing nucleic acid chemistry, here we present an artificial base-directed topological single-strand DNA encoding design that enables one-step synthesis of valence-controlled NIR-II molecular nanostructures and spatial assembly of these nanostructures to modulate their behaviors in living systems. As proof-of-concept studies, we construct ultrasmall Ag2 S quantum dots and pH-responsive, size-tunable CuS assemblies for in vivo NIR-II fluorescence imaging and deep tumor photothermal therapy. This work paves a new way for creating functionally diversified architectures and broadens the scope of DNA-encoded material engineering.

Mechanical metamaterial design with the customized low-frequency bandgap and negative Poisson's ratio via topology optimization

The precise control of both the mechanical deformation and wave propagation characteristics of metamaterial through design holds significant importance and presents a challenging task. This paper proposes a novel two-stage topological optimization design method for customizing both negative Poisson's ratio and locally resonant bandgap in the mechanical metamaterial. In the optimized model, the negative Poisson’s ratio structure is firstly obtained by optimizing the material distribution within the matrix region, then the metamaterial with the customized negative Poisson’s ratio and bandgap range is obtained through the second stage optimization. In the analysis of the metamaterial unit cell, the topology-dependent Poisson’s ratio is calculated based on the equivalent elastic matrix obtained through the homogenization method. The range of bandgap is estimated using the effective mass analytical model of the spring-mass system. Thus, the range of bandgap is determined by only a few geometric parameters instead of topological structure under given assumptions. The customized bandgap ranges can be extended by introducing more resonators into the unit cell and combining different unit cells into an assembled structure. Numerical examples are provided to demonstrate the efficacy of the proposed method.

Hierarchically Porous Covalent Organic Frameworks: Synthesis Methods and Applications.

Covalent organic frameworks (COFs) with high porosity have garnered considerable interest for various applications owing to their robust and customizable structure. However, conventional COFs are hindered by their narrow pore size, which poses limitations for applications such as heterogeneous catalysis and guest delivery that typically involve large molecules. The development of hierarchically porous COF (HP-COF), featuring a multi-scale aperture distribution, offers a promising solution by significantly enhancing the diffusion capacity and mass transfer for larger molecules. This review focuses on the recent advances in the synthesis strategies of HP-COF materials, including topological structure design, in-situ templating, monolithic COF synthesis, defect engineering, and crystalline self-transformation. The specific operational principles and affecting factors in the synthesis process are summarized and discussed, along with the applications of HP-COFs in heterogeneous catalysis, toxic component treatment, optoelectronics, and the biomedical field. Overall, this review builds a bridge to understand HP-COFs and provides guidance for further development of them on synthesis strategies and applications.

Sub‐Stoichiometric Covalent Organic Frameworks

AbstractCovalent organic frameworks (COFs) have garnered significant attention for nearly two decades due to their exceptional structural designs, tunable properties, and wide‐ranging applications. Recently, a novel subclass of COFs known as partially condensed, sub‐stoichiometric COFs (ss‐COFs) has emerged. This presents a promising new avenue for constructing distinct COF structures in contrast to fully condensed, stoichiometric COFs (fc‐COFs). ss‐COFs are deliberately designed with periodic unreacted functional groups, thereby giving rise to intriguing electronic, optical, and catalytic properties. The deviation from conventional stoichiometric approach opens up new prospects to tailor material properties for unexplored applications. Here, this review focuses on the latest advancements and breakthroughs in ss‐COFs, including topological design, structure characterization, synthetic method, and practical applications. From their basic designing principles to cutting‐edge properties, it will be explored how ss‐COFs are paving the way for COFs research and pushing the boundaries toward new scientific and technological possibilities.

Configuration design and crease topology of origami-inspired spinning space deployable structures

Origami-inspired space deployable structures can be transformed from the folded states into the deployed states in orbit, which satisfied the demands of complex space missions and had been widely used in the space field. It remains to be investigated how the space deployable structures realized a large deployable ratio in the crease design process of origami patterns for the storage space limitation of spacecraft structures. Origami-inspired Regular Polygons Deployable Structures (RPDS) were proposed by designing the origami configurations and analyzing the deployable mechanism from existing space deployable structures, and a novel crease topology with three different approaches was presented in repeating origami modules to enhance the deployable ratio. The topology results indicated that the deployable ratio of RPDS can be increased effectively by shortening the storage height or performing multi-stage deployment, and the flexibility of RPDS can be verified by changing the shape of the central body. The configuration rationality and deployable reliability of RPDS are confirmed by kinematic modeling and numerical simulation. This study provides new insights into extraordinary geometrical and folding properties of origami-inspired deployable structures via configuration design and crease topology, which can be extended to other origami patterns in various origami-inspired applications.

Distributed Interval Observers with Switching Topology Design for Cyber-Physical Systems

In this paper, the distributed interval estimation problem for networked Cyber-Physical systems suffering from both disturbances and noise is investigated. In the distributed interval observers, there are some connected interval observers built for the corresponding subsystems. Then, due to the communication burden in Cyber-Physical systems, we consider the case where the communication among distributed interval observers is switching topology. A novel approach that combines L∞ methodology with reachable set analysis is proposed to design distributed interval observers. Finally, the performance of the proposed distributed interval observers with switching topology is verified through a simulation example.

A microparticle manipulation method facilitated via microfluidic chip based on swirling flow topology design and its application in sorting

Microfluidics technology is trustworthy for microparticle operation as it doesn't involve destructive contact. Our research endeavors have encompassed microparticles manipulation by generating swirling flow region (SFR). Now we try to utilize swirl and flow topology to promote microfluidic chip design because serial operation is still not well enabled. Herein, a new model is proposed for a 6-microchannel microfluidic chip, which has realized active control of microparticles. The chip is capable of trapping, transferring, and enriching microparticles, and is applied for microparticles sorting. Simulation is performed to substantiate the viability of generating SFRs, and experiments are conducted on 3D-printed chips to validate the envisioned functions of the proposed microfluidic chip. Encouragingly, our experiments yield convincing outcomes, wherein microparticles are successfully trapped, transferred, and enriched in separated SFRs. With the help of a self-developed vision algorithm, the size sorting of microparticles is facilitated. Significantly, the manipulation of different microparticles can be achieved by tuning the microchannel velocities and tailoring the flow topology. This work presents a pioneering flow field structure and provides a feasible scheme for sorting microparticles, which is a noteworthy advance in swirl-based microfluidic chip applications. It is a potential mean for bio-/chemical analysis and fluidic-directed assembly of multiple microparticles.

Topological corner states in a silicon nitride photonic crystal membrane with a large bandgap.

The theory of band topology has inspired the discovery of various topologically protected states in the regime of photonics. It has led to the development of topological photonic devices with robust property and versatile functionalities, like unidirectional waveguides, compact power splitters, high-Q resonators, and robust lasers. These devices mainly rely on the on-chip photonic crystal (PhC) in Si or III-V compound materials with a fairly large bandgap. However, the topological designs have rarely been applied to the ultra-low-loss silicon nitride (SiN) platform which is widely used in silicon photonics for important devices and integrated photonic circuits. It is mainly hindered by the relatively low refractive index. In this work, we revealed that a rhombic PhC can open a large bandgap in the SiN slab, and thus support robust topological corner states stemming from the quantization of the dipole moments. Meanwhile, we propose the inclination angle of rhombic lattice, as a new degree of freedom, to manipulate the characteristics of topological states. Our work shows a possibility to further expand the topological protection and design flexibility to SiN photonic devices.

Performance Analysis of Hybrid Comparator using 45nm Technology

In the present real-time world, due to the improvements and innovations of System on Chip (SoC) applications, there is a requirement to integrate multiple technology design topologies. The electronic system design is classified as analog, digital, and mixed-signal design. The comparator is the major building block used in the datapath of System on Chip (SoC) application device. The usage of these devices depends on not only functionality but also on the non-functionality parameters considering different performance estimation metrics. The nonfunctional performance metrics for a transistor level design depends on the number of transistors, switching activities of logic level voltages and delay between input and outputs. These performance metrics are improved by considering the multiple logic families for multiple output generations instead of using a single logic family topology. The comparator is the major component in the arithmetic circuits for SoC applications and can be realized by using various design topologies. The vividly used topologies are Conventional CMOS logic, Pass Transistor Logic (PTL), Gate Diffusion Input (GDI) Logic, Stacking technique, Quantum-dot cellular automata, etc. The selection of the design topology for the comparator is made based on the non-functional parameters. The performance of non-functional parameters is improved by combining the topology architectures of different design techniques. In this paper, the comparator is designed using conventional CMOS logic, PTL, GDI, and a hybridized topology for best performance and the same is implemented using 45nm technology. These circuits are designed by using Cadence Virtuoso Electronic Design Automation (EDA) design tools. Non-functional performance parameters are analyzed for different topologies. Index Terms: VLSI Design, Comparator, Datapath, EDA tools, CMOS Logic, GDI Logic, PTL Logic.

Enhancing the Efficiency of Multi-Electrolyzer Clusters with Lye Mixer: Topology Design and Control Strategy

Enhancing the Efficiency of Multi-Electrolyzer Clusters with Lye Mixer: Topology Design and Control Strategy

Next generation induction heating: GAN vs. MOSFET based resonant power converter for residential use

Flexible-surface induction cooktops require handling various induction heating loads simultaneously, each with different behaviors and power requirements. Multi-output inverter topologies are designed to manage power independently with minimal components and high power density. However, traditional modulation strategies face limitations in ensuring soft switching for reduced losses. Wide band gap devices offer a new approach, where soft switching isn't necessary for high efficiency. To achieve flexibility, domestic induction heating relies on multi-coil structures for optimal temperature distribution. Different coil-pot systems are treated as independent loads, each with specific parameters and power needs. Multi-output topologies, derived from full bridge, half-bridge, and single switch configurations, are developed to tackle the challenge of multi-load power transmission. These topologies balance complexity, versatility, and efficiency based on factors like inductor size, number, target material, and heating distance. A cost-effective and versatile family of multi-output resonant inverters, derived from the half-bridge topology, is described. This work further develops this idea by proposing a high-efficiency implementation of an array multi-output converter with a column structure able to operate under load mismatch achieving reduced power losses, which eases integration into a flexible IH cooktop. Highefficiency multi-output converters are a key enabling technology for the widespread use of flexible surface IH cooktops. Due to the application characteristics, complex modulation strategies appear, requiring an additional effort in the topology design, ensuring reduced power losses regardless of the nature of the switching sequence. However, they suffer from limitations when applying classical modulation strategies to ensure soft switching, which is required to reduce transistor losses and achieve efficient operation. The prototype shows different outputs for induction heating, and in the future, those outputs can be used to develop the IH cooktop.

Topology design and control strategy of bidirectional DC/DC converter for electric vehicles

Topology design and control strategy of bidirectional DC/DC converter for electric vehicles

Design and simulation of bidirectional DC-DC converter topology for battery applications

Recently, energy storage has become a significant topic for renewable energy based power system applications. Batteries are one of the most popular energy storage devices adopted by renewable energy sources, electrical vehicles and grid connected systems. In this context, the bidirectional DC-DC converter (BDC) enables bidirectional power flow by controlling the charging and discharging stage of the battery in battery applications. Accordingly, the battery current is regulated through the duty cycle of the BDC considering the state of charge of the battery and current direction. In this study, a non-isolated BDC, has a buck and boost principle of operation, is designed, analysed and simulated under various case studies. In the designed system, BDC controls the bidirectional power flow between the battery and DC link. Specifically, in the charging stage of battery operating in buck mode, DC-link supplies the power to the battery and BDC regulates the battery current using proportional-integral (PI) controller. On the other hand, in the discharging stage of the battery operating in boost mode, when DC source is disconnected, the battery supplies the power to DC load and DC-link voltage is controlled by the BDC via PI controller. The simulation results are presented to show the operation and control of the BDC under different scenarios.

Design of Radiation Protection Topology for Pulsed High Currents in Electromagnetic Launcher based on Decision Variable Analysis

Design of Radiation Protection Topology for Pulsed High Currents in Electromagnetic Launcher based on Decision Variable Analysis

Polymer mechanochemistry: from single molecule to bulk material.

The field of polymer mechanochemistry has experienced a renaissance over the past decades, primarily propelled by the rapid development of force-sensitive molecular units (i.e., mechanophores) and principles governing the reactivity of polymer networks for mechanochemical transduction or material strengthening. In addition to fundamental guidelines for converting mechanical energy input into chemical output, there has also been increasing focus on engineering applications of polymer mechanochemistry for specific functions, mechanically adaptive material systems, and smart devices. These endeavors are made possible by multidisciplinary approaches involving the development of multifunctional mechanophores for mechanoresponsive polymer systems, mechanochemical catalysis and synthesis, three-dimensional (3D) printed mechanochromic materials, reasonable design of polymer network topology, and computational modeling. The aim of this minireview is to provide a summary of recent advancements in covalent polymer mechanochemistry. We specifically focus on productive mechanophores, mechanical remodeling of polymeric materials, and the development of theoretical concepts.

Dual LCL resonance compensation for the design of electric vehicle wireless energy transmission system topology

Dual LCL resonance compensation for the design of electric vehicle wireless energy transmission system topology

Grouping-Based Optimal Design of Collector System Topology for a Large-Scale Offshore Wind Farm by Improved Simulated Annealing

Grouping-Based Optimal Design of Collector System Topology for a Large-Scale Offshore Wind Farm by Improved Simulated Annealing

Design and analysis of novel topology for PV-FED EV charging system

Design and analysis of novel topology for PV-FED EV charging system

Precision-engineered metal–organic frameworks: fine-tuning reverse topological structure prediction and design

A fine-tuned reverse topological approach is developed for structure prediction and 94 823 precision-engineered metal–organic frameworks are designed.

Simultaneous topology design and optimization of PDE constrained processes based on mixed integer formulations

Simultaneous topological design and optimization of complex processes that are described by partial differential equations is a challenging but promising research area. Widely adopted nested and sequential approaches are mostly applicable based on heuristic solutions, hindering the theoretical improvement potential due to decentralized decision-making in subsequent stages with a significant number of trial-and-error procedures. This study introduces a mixed integer formulation addressing the governing equations and case-dependent topological constraints at each discretization point, enabling solutions through rigorous solvers under process-related constraints and objectives. Nonlinear expressions in the formulations are further tailored using piecewise linear approximations, still representing the major nonlinear trends through a mixed-integer linear nature to favor global optimality and benefit from computational advancements, when needed. Heat and Stokes flow problems are used as case studies to demonstrate the applicability of the methodology.