Tunable Architecture Research Articles

Reentrant DNA shells tune polyphosphate condensate size

The inorganic biopolymer polyphosphate (polyP) occurs in all domains of life and affects myriad cellular processes. A longstanding observation is polyP’s frequent proximity to chromatin, and, in many bacteria, its occurrence as magnesium (Mg2+)-enriched condensates embedded in the nucleoid region, particularly in response to stress. The physical basis of the interaction between polyP, DNA and Mg2+, and the resulting effects on the organization of the nucleoid and polyP condensates, remain poorly understood. Here, using a minimal system of polyP, Mg2+, and DNA, we find that DNA can form shells around polyP-Mg2+ condensates. These shells show reentrant behavior, that is, they form within a window of Mg2+ concentrations, representing a tunable architecture with potential relevance in other multicomponent condensates. This surface association tunes condensate size and DNA morphology in a manner dependent on DNA length and concentration, even at DNA concentrations orders of magnitude lower than found in the cell. Our work also highlights the remarkable capacity of two primordial inorganic species to organize DNA.

Role of delay in brain dynamics

Significant variations of delays among connecting neurons cause an inevitable disadvantage of asynchronous brain dynamics compared to synchronous deep learning. However, this study demonstrates that this disadvantage can be converted into a computational advantage using a network with a single output and M multiple delays between successive layers, thereby generating a polynomial time-series outputs with M. The proposed role of delay in brain dynamics (RoDiB) model, is capable of learning increasing number of classified labels using a fixed architecture, and overcomes the inflexibility of the brain to update the learning architecture using additional neurons and connections. Moreover, the achievable accuracies of the RoDiB system are comparable with those of its counterpart tunable single delay architectures with M outputs. Further, the accuracies are significantly enhanced when the number of output labels exceeds its fully connected input size. The results are mainly obtained using simulations of VGG-6 on CIFAR datasets and also include multiple label inputs. However, currently only a small fraction of the abundant number of RoDiB outputs is utilized, thereby suggesting its potential for advanced computational power yet to be discovered.

Reprocessable and Mechanically Tailored Soft Architectures Through 3D Printing of Elastomeric Block Copolymers

AbstractThermoplastic elastomers (TPEs) are nanostructured, melt‐processable, elastomeric block copolymers. When TPEs that form cylindrical or lamellar nanostructures are macroscopically oriented, their material properties can exhibit several orders of magnitude of anisotropy. Here it is demonstrated that the flows applied during the 3D printing of a cylinder‐forming TPE enable hierarchical control over material nanostructure and function. It is demonstrated that 3D printing allows for control over the extent of nanostructural and mechanical anisotropy and that thermal annealing of 3D printed structures leads to highly anisotropic properties (up to 85 × anisotropic tensile modulus). This approach is leveraged to print functional soft 3D architectures with tunable local and macroscopic mechanical responses. Further, these printed TPEs intrinsically achieve melt‐reprocessability over multiple cycles, reprogrammability, and robust self‐healing via a brief period of thermal annealing, enabling facile fabrication of highly tunable, robust, and recyclable soft architectures.

Tuning the Electronic Structures of Mo-Based Sulfides/Selenides with Biomass-Derived Carbon for Hydrogen Evolution Reaction and Sodium-Ion Batteries

A key research focus at present is the exploration and innovation of electrode materials suitable for energy storage and conversion. Molybdenum-based sulfides/selenides (primarily MoS2 and MoSe2) have garnered attention in recent years due to their intrinsic two-dimensional structures, which are conducive to ion/electron transfer or insertion/extraction, making them promising candidates in electrocatalytic hydrogen production and sodium-ion battery applications. However, their inherently poor electronic structures have led most research efforts to concentrate on modifications aimed at enhancing their performance in hydrogen evolution reactions (HERs) and sodium-ion batteries (SIBs). Owing to their remarkable chemical inertness, expansive specific surface areas, and tunable pore architectures, carbon-based materials have garnered significant attention in research. The utilization of biomass as a renewable and environmentally sustainable precursor offers considerable benefits, including abundant availability, ecological compatibility, and cost-effectiveness. Consequently, recent scholarly endeavors have concentrated intensively on the synthesis of valuable carbon materials derived from renewable biomass sources. This review addresses the scientific challenges related to the development of electrode materials for HERs and SIBs in electrochemical energy storage and conversion. It delves into the recent focus on the two-dimensional transition-metal chalcogenides, particularly MoS2 and MoSe2, and the difficulties encountered in modulating their electronic structures when applied to HERs and SIBs. The review proposes the use of eco-friendly and widely sourced biomass-derived carbon (BMC) as a supporting matrix combined with MoS2 and MoSe2 to regulate their structures and enhance their electrocatalytic activity and sodium storage performance. Additionally, it highlights the existing challenges faced by these BMC/MoS2 and BMC/MoSe2 composites and offers insights into future developments.

Engineering ion diffusion and electron transfer dual pathways within porous spherical H1.6Mn1.6O4 for highly efficient Li+ separation

Efficient and selective electrochemical lithium adsorption from liquid resources is crucial for sustainable lithium extraction and purification. However, the sluggish Li+ diffusion kinetics often lag behind electron transfer rates, hindering the overall adsorption efficiency in capacity and kinetics. This work addresses this challenge by introducing a tunable porous spherical architecture in H1.6Mn1.6O4 adsorbent particles. The Li+ diffusion coefficient (DLi+) enhanced from 1.32 × 10-12 cm2/s to 3.61 × 10-12 cm2/s, the solution resistance (Rs) decreased from 28.88 ohm to 25.30 ohm, the charge transfer resistance (Rct) decreased from 31.04 ohm to 30.40 ohm, and the desolvation activation energy (Ea) reduced from 10.81 kJ/mol to 9.81 kJ/mol. Consequently, the optimized porous spherical H1.6Mn1.6O4 demonstrates superior adsorption capacity and adsorption kinetics, exceeding 24.23 mg/g at 180 min, which is 1.26 times that of the dense spherical counterpart (19.28 mg/g). The simulation calculations of Li+ diffusion highlight the pivotal role of the porous structure in accelerating internal Li+ diffusion, thereby significantly contributing to the enhanced overall adsorption efficiency of H1.6Mn1.6O4. This work emphasizes the significance of synergistically optimizing ion diffusion channels and electron transfer paths for enhancing electrochemical processes and provides a path for constructing similar pore structures in various ion–electron-related applications.

Bio-adsorbents based on mesoporous silica produced from rice husks with tunable architecture and surface area for remediation of industrial effluents

Bio-adsorbents based on mesoporous silica produced from rice husks with tunable architecture and surface area for remediation of industrial effluents

Continuous glass fiber‐reinforced polycaprolactone composite produced in a conventional fused filament fabrication equipment: Process modeling and parameters adjustment

AbstractPolymer composites with continuous fibers are expected to exhibit good mechanical performance due to orientation and high aspect ratio of fillers. Fused filament fabrication (FFF) provides an affordable method for processing these materials as products with tunable architecture. By incorporating continuous bioactive fibers coated with biodegradable polymer, the degradation rate of printed scaffolds may vary over time. As proof of concept, macroporous composites were 3D printed using continuous glass fiber‐reinforced polycaprolactone filament. Parametrization and challenges associated with printing on non‐dedicated equipment are discussed. A model describing the melt flow was employed to evaluate the velocity and shear rate profiles. Although the maximum velocity is approximately 18 mm s−1 for both neat and reinforced polymer, the obstruction caused by fibers results in higher shear rate, up to 481 s−1, higher pressure gradient, 1.95 MPa mm−1, and higher velocity gradient, conditions that limit print quality. Additionally, it was also possible to determine the shear stress experienced by the fiber bundle, 300 KPa, and the influence of different processing conditions. This investigation advances the development and understanding of manufacturing of continuous fiber‐reinforced polymers via FFF.

Engineering of Asymmetric Hollow Carbon Nanoparticles with Tunable Architecture via Flowable Colloidal Polymer‐Emulsion Assembly Strategy

Engineering of Asymmetric Hollow Carbon Nanoparticles with Tunable Architecture via Flowable Colloidal Polymer‐Emulsion Assembly Strategy

Structural Characterization of Disulfide-Linked p53-Derived Peptide Dimers.

Disulfide bonds provide a convenient method for chemoselective alteration of peptide and protein structure and function. We previously reported that mild oxidation of a p53-derived bisthiol peptide (CTFANLWRLLAQNC) under dilute non-denaturing conditions led to unexpected disulfide-linked dimers as the exclusive product. The dimers were antiparallel, significantly α-helical, resistant to protease degradation, and easily reduced back to the original bisthiol peptide. Here we examine the intrinsic factors influencing peptide dimerization using a combination of amino acid substitution, circular dichroism (CD) spectroscopy, and X-ray crystallography. CD analysis of peptide variants suggests critical roles for Leu6 and Leu10 in the formation of stable disulfide-linked dimers. The 1.0 Å resolution crystal structure of the peptide dimer supports these data, revealing a leucine-rich LxxLL dimer interface with canonical knobs-into-holes packing. Two levels of higher-order oligomerization are also observed in the crystal: an antiparallel "dimer of dimers" mediated by Phe3 and Trp7 residues in the asymmetric unit and a tetramer of dimers mediated by Trp7 and Leu10. In CD spectra of Trp-containing peptide variants, minima at 227 nm provide evidence for the dimer of dimers in dilute aqueous solution. Importantly, and in contrast to the original dimer model, the canonical leucine-rich core and robust dimerization of most peptide variants suggests a tunable molecular architecture to target various proteins and evaluate how folding and oligomerization impact various properties, such as cell permeability.

3D-printed polymer-derived ceramics with tunable cellular architectures

Ceramic materials possess high mechanical strength and environmental stability, but their brittleness limits their suitability for structural applications. A solution lies in using polymer-derived ceramics (PDCs), which offer enhanced toughness and versatility in shaping unlike traditional ceramic processing methods. This study explores tunable ceramic cellular architectures based on triply periodic minimal surface (TPMS) designs, fabricated via stereolithography (SLA) using a silicon oxycarbide precursor formulated for vat photopolymerization. By combining the preceramic polymer with a photoinitiator, crosslinkers, and other additives, intricate shapes are 3D-printed and then pyrolyzed under nitrogen, resulting in PDCs with complex TPMS geometries. The toughness, strength, and stiffness of the 3D-printed structures are evaluated through quasi-static compression experiments. Comprehensive material and microstructural characterizations of the PDCs are performed pre- and post-pyrolysis, employing visual inspection, X-ray micro-tomography, thermogravimetric analysis, energy dispersive X-ray spectroscopy, density, and rheological measurements. Optimization of 3D printing and pyrolysis parameters yields ceramic structures with 2.2 MPa compressive strength and 330 MPa stiffness with a lattice density of 0.5 g cm-3. The ceramic material, including porosity, had a maximum density of 1.63 ± 0.01 g cm-3. This low-cost SLA 3D printing technique is ideal for creating thin features and customized structures of bio-inspired, architectured ceramics. Furthermore, the process exhibits excellent printability, being compatible with common and cost-effective SLA, DLP, and LCD 3D printers.

Charge-parity switching effects and optimisation of transmon-qubit design parameters

Enhancing the performance of noisy quantum processors requires improving our understanding of error mechanisms and the ways to overcome them. A judicious selection of qubit design parameters plays a pivotal role in improving the performance of quantum processors. In this study, we identify optimal ranges for qubit design parameters, grounded in comprehensive noise modeling. To this end, we also analyze the effect of a charge-parity switch caused by quasiparticles on a two-qubit gate. Due to the utilization of the second excited state of a transmon, where the charge dispersion is significantly larger, a charge-parity switch will affect the conditional phase of the two-qubit gate. We derive an analytical expression for the infidelity of a diabatic controlled-Z gate and see effects of similar magnitude in adiabatic controlled-phase gates in the tunable coupler architecture. Moreover, we show that the effect of a charge-parity switch can be the dominant quasiparticle-related error source of a two-qubit gate. We also demonstrate that charge-parity switches induce a residual longitudinal interaction between qubits in a tunable-coupler circuit. Furthermore, we introduce a performance metric for quantum circuit execution, encompassing the fidelity and number of single- and two-qubit gates in an algorithm, as well as the state preparation fidelity. This comprehensive metric, coupled with a detailed noise model, enables us to determine an optimal range for the qubit design parameters, as confirmed by numerical simulation. Our systematic analysis offers insights and serves as a guiding framework for the development of the next generation of transmon-based quantum processors.

Band engineering in two-dimensional porphyrin- and phthalocyanine-based covalent organic frameworks: insight from molecular design

Two-dimensional covalent organic frameworks (2D COFs) represent an emerging class of crystalline polymeric networks, characterized by their tunable architectures and porosity, synthetic adaptability, and interesting optical, magnetic, and electrical properties. The incorporation of porphyrin (Por) or phthalocyanine (Pc) core units into 2D COFs provides an ideal platform for exploring the relationship between the COF geometric structure and its electronic properties in the case of tetragonal symmetry. In this work, on the basis of tight-binding models and density functional theory calculations, we describe the generic types of electronic band structures that can arise in tetragonal COFs. Three tetragonal lattice symmetries are examined: the basic square lattice, the Lieb lattice, and the checkerboard lattice. The potential topological characteristics of each lattice are explored. The Por-/Pc-based COFs exhibit characteristic band dispersions that are directly linked to their lattice symmetries and the nature of the frontier molecular orbitals of their building units. We show that the band dispersions in these COFs can be tailored by choosing specific symmetries of the molecular building units and/or by modulating the relative energies of the core and linker units. These strategies can be extended to a wide array of COFs, offering an effective approach to engineering their electronic properties.

Tailoring 3D conductive networks as wearable sensors for pressure or temperature sensing

Wearable and highly sensitive sensors that can detect different stimuli are essential in versatile applications. Despite some progress has been achieved on multi-sensing functions, the construction of flexible pressure and temperature sensors with desirable sensing performances in facile and cost-effective process still remains a challenge. Here, a flexible sensor with conductive porous structure is proposed by simply combining carbon black (CB) and thermoplastic polyurethane (TPU) via sugar-templated pore making strategy. Notably, moderate CB filler amount (30 %) and tunable porous architecture endow the fabricated sensor with satisfactory sensitivity (−3.63 kPa−1), fast response (123 ms), and fascinating recoverability (6000 cycles). In addition to the mechanical stimulus reception, the sensor is demonstrated to possess thermosensitive ability, allowing the real-time capture of the electrical characteristics to temperature change. Furthermore, an integrated sensor array can be realized to detect spatial distribution of pressure/temperature, suggesting the possibility in health-status monitoring, environmental sensing and electronic skin.

Covalent Organic Framework-Based Materials for Advanced Lithium Metal Batteries.

Lithium metal batteries (LMBs), with high energy densities, are strong contenders for the next generation of energy storage systems. Nevertheless, the unregulated growth of lithium dendrites and the unstable solid electrolyte interphase (SEI) significantly hamper their cycling efficiency and raise serious safety concerns, rendering LMBs unfeasible for real-world implementation. Covalent organic frameworks (COFs) and their derivatives have emerged as multifunctional materials with significant potential for addressing the inherent problems of the anode electrode of the lithium metal. This potential stems from their abundant metal-affine functional groups, internal channels, and widely tunable architecture. The original COFs, their derivatives, and COF-based composites can effectively guide the uniform deposition of lithium ions by enhancing conductivity, transport efficiency, and mechanical strength, thereby mitigating the issue of lithium dendrite growth. This review provides a comprehensive analysis of COF-based and derived materials employed for mitigating the challenges posed by lithium dendrites in LMB. Additionally, we present prospects and recommendations for the design and engineering of materials and architectures that can render LMBs feasible for practical applications.

Universal Carbonizable Filaments for 3D Printing

AbstractCarbon additive manufacturing emerges as a powerful technique for crafting tunable 3D carbon architectures, employing multiscale arrangement and topological design for mechanical and functional applications. However, the potential of 3D carbon fabrication is constrained when utilizing state‐of‐the‐art feedstock and manufacturing routes. To address these limitations, a 3D carbon fabrication strategy is developed named carbonizable filament technology (CAFIT). In CAFIT, the evolution of high‐loaded carbon composite filaments broadens the capabilities of straightforward 3D printing technology by ensuring structural stability for subsequent post‐carbonization to achieve scalable and engineered 3D carbon structures. This strategy has strengths regarding 1) simplicity, 2) applicability to a variety of carbon materials, and 3) creating nearly replicated 3D carbon structures with multiscale features. The fundamental mechanisms governing the processability of the universal filament and structural change of carbon particles throughout the process using carbon nanotubes as an example are explored. Moreover, through simulation and demonstration, the adaptability of CAFIT is illustrated by utilizing a wide range of carbon materials, including low‐dimensional nano/micro carbons (carbon blacks, carbon nanotubes, and graphenes), as well as carbon fibers, to fabricate 3D architected carbon structures.

Predictive lumped model for a tunable bistable piezoelectric energy harvester architecture

In this article, we propose the modelling of a tunable bistable piezoelectric energy harvester (or BPEH) architecture. The latter is a type of ambient energy converter that continues to gain attention due to their wideband frequency response. As the non-linear dynamics of BPEHs imply significant modeling complexity, dynamic lumped models are necessary to predict BPEHs’ dynamic response and should fit the type of architecture studied. The BPEH architecture of interest uses post-buckled beams to create bistability and an amplified piezoelectric actuator (or APA) to convert the ambient vibrations. To date, no dynamic lumped models have been found in existing literature that account for both the electromechanical conversion and the dynamic behavior of buckled beams, with a specific focus on their axial and bending stiffness, for this BPEH architecture. Additionally, the proposed BPEH architecture offers buckling level tunability, which is achieved using an additional APA. Hence, the aim of this paper is to propose a new lumped model for a BPEH architecture that considers the effect of the post-buckled beams’ stiffness and of the additional APA through an elasticity factor κ― . This lumped model is established using Euler Lagrange equations and is experimentally validated on a tunable BPEH prototype. This validation shows an average relative error below 6% between the model predictions and experimental dynamic response of the prototype to an ascending frequency sweep, compared to an average relative error that is around 14% for the model proposed in literature. Moreover, numerical simulations using the proposed model lead to the conclusion that there is an optimal elasticity factor κ― that ensures the maximum power output while maintaining the frequency bandwidth.

Liposome-integrated hydrogel hybrids: Promising platforms for cancer therapy and tissue regeneration

Drug delivery platforms have gracefully emerged as an indispensable component of novel cancer chemotherapy, bestowing targeted drug distribution, elevating therapeutic effects, and reducing the burden of unwanted side effects. In this context, hybrid delivery systems artfully harnessing the virtues of liposomes and hydrogels bring remarkable benefits, especially for localized cancer therapy, including intensified stability, excellent amenability to hydrophobic and hydrophilic medications, controlled liberation behavior, and appropriate mucoadhesion to mucopenetration shift. Moreover, three-dimensional biocompatible liposome-integrated hydrogel networks have attracted unprecedented interest in tissue regeneration, given their tunable architecture and physicochemical properties, as well as enhanced mechanical support. This review elucidates and presents cutting-edge developments in recruiting liposome-integrated hydrogel systems for cancer treatment and tissue regeneration.

Engineering lignin-derivable diacrylate networks with tunable architecture and mechanics

Thermomechanical properties are tuned by varying diacrylate content and size in lignin-derivable networks, highlighting the design of processable, fully renewable, and performance-driven (meth)acrylate networks using network engineering approaches.

Tunable architectures of electrospun cellulose acetate phthalate applied as thickeners in green semisolid lubricants

Lubricants play a pivotal role in reducing wastage-to-energy caused by friction and increasing efficiency and durability by decreasing production and manufacturing costs. In this work, an efficient and innovative methodology founded on the electrospinning technique aiming to develop eco-friendly cellulose acetate phthalate (CAph) dispersions in castor oil with potential application in lubrication was proposed. With this in mind, the electrospinnability of CAph solutions and the ability of the different micro- and nano-architectures generated to thicken castor oil were studied. Particles, beaded-fibers and defect-free fibers were successfully produced by using CAph solutions with concentration between 10 and 30 wt%. The formation of bead-free nanofibers was favored at concentration above 20 wt%, achieving relaxation times of at least 13 ms, and non-Newtonian character in shear tests. All the electrospun CAph micro- or nano-structures leaded to physically stable oleo-dispersions, even at low concentrations (3 wt%), providing a wide variety of rheological and tribological as the dispersions undergone structural transitions due to changes in the thickener morphologies and/or concentrations, as shown by SAOS and creep-recovery data, oil holding capacity, and tackiness, wear and friction performance in metal–metal contact. Some of the oleo-dispersions formulated with defect-free CAph nanofibers exhibited similar rheological response and better tribological properties than traditional lithium lubricating greases which are the current benchmark.

Tunable architectures in Al/Al2O3 composites for enhanced damage tolerance using zirconium acetate-mediated ice-templating

Achieving lightweight, robust, and resilient materials is a sought-after goal, yet concurrently achieving these attributes presents a substantial challenge. A biomimetic design approach opens doors to innovative possibilities in this domain. In this paper, we use the ice-shaping properties of zirconium acetate (ZRA) to obtain Al/Al2O3 composites with tunable architectures through freeze casting and pressure infiltration. The concentration of ZRA in the initial slurry is critical in controlling the final structure of the composites. The composites’ bending strength, compressive strength, and crack-initiation fracture toughness KIc improve with increasing ZRA concentration in the initial slurry. Interestingly, the crack-extension fracture toughness KJc demonstrates an initial decrease followed by subsequent improvement. In addition, the relationship between cracking mode and structural features in the composites is elucidated to explain the underlying strengthening and toughening mechanisms. This tunable and scale-able ice-templating and manufacturing approach opens new doors for developing high-performance metal-ceramic composites.