Design Strategies Research Articles

Applying a User-Centered Design Framework to Develop a Remote Research Assessment Protocol for a Randomized Clinical Trial for Toddlers with Early Autism Characteristics.

COVID-19 required many research teams to shift from in-person to remote assessments, which posed both procedural and theoretical challenges. While research has explored the utility of remote assessments for autism diagnosis from the perspective of families and clinicians, less is known about their application in clinical trials. This paper describes the development of a remote research assessment protocol for a randomized clinical trial focusing on the implementation of reciprocal imitation teaching (RIT) with toddlers in Part C early intervention. This project spans two phases. For Phase 1, our team developed and documented a series of steps utilizing user-centered design (UCD) strategies (e.g., recruiting potential users, creating a prototype, engaging in iterative development) for the purpose of redesigning an assessment protocol for a remote environment. For Phase 2, we examined preliminary outcomes of the redesign process. Primary end users (assessors) rated post-redesign usability and acceptability, while acceptability was examined using attrition data from secondary end users (family participants). Preliminary fidelity of implementation was also examined. The iterative redesign process allowed the research team to refine aspects of the assessment that ultimately led to promising preliminary ratings of usability, acceptability, and feasibility, as well as high fidelity. Preliminary data suggest that the redesigned assessment appears to be an acceptable, feasible, and usable tool for autism clinical trial research and that assessors can use it with fidelity. Further research is needed to examine the reliability and validity of the assessment, as well as implementation characteristics on a larger scale.

Laser Precise Synthesis of Oxidation-Free High-Entropy Alloy Nanoparticle Libraries.

High-entropy alloy nanoparticles (HEA-NPs) show exceptional properties and great potential as a new generation of functional materials, yet a universal and facile synthetic strategy in air toward nonoxidized and precisely controlled composition remains a huge challenge. Here we provide a laser scribing method to prepare single-phase solid solution HEA-NPs libraries in air with tunable composition at the atomic level, taking advantage of the laser-induced metastable thermodynamics and substrate-assisted confinement effect. The three-dimensional porous graphene substrate functions as a microreactor during the fast heating/cooling process, which is conductive to the generation of the pure alloy phase by effectively blocking the binding of oxygen and metals, but is also beneficial for realizing accurate composition control via microstructure confinement-endowed favorable vapor pressure. Furthermore, by combining an active learning approach based on an adaptive design strategy, we discover an optimal composition of quinary HEA-NP catalysts with an ultralow overpotential for Li-CO2 batteries. This method provides a simple, fast, and universal in-air route toward the controllable synthesis of HEA-NPs, potentially integrated with machine learning to accelerate the research on HEAs.

Regulation of Interfacial Chemistry Enabling High-Power Dual-Ion Batteries at Low Temperatures.

Interfacial chemistry plays a crucial role in determining the electrochemical properties of low-temperature rechargeable batteries. Although existing interface engineering has significantly improved the capacity of rechargeable batteries operating at low temperatures, challenges such as sharp voltage drops and poor high-rate discharge capabilities continue to limit their applications in extreme environments. In this study, an energy-level-adaptive design strategy for electrolytes to regulate interfacial chemistry in low-temperature Li||graphite dual-ion batteries (DIBs) is proposed. This strategy enables the construction of robust interphases with superior ion-transfer kinetics. On the graphite cathode, the design endues the cathode interface with solvent/anion-coupled interfacial chemistry, which yields an nitrogen/phosphor/sulfur/fluorin (N/P/S/F)-containing organic-rich interphase to boost anion-transfer kinetics and maintains excellent interfacial stability. On the Li metal anode, the anion-derived interfacial chemistry promotes the formation of an inorganic-dominant LiF-rich interphase, which effectively suppresses Li dendrite growth and improves the Li plating/stripping kinetics at low temperatures. Consequently, the DIBs can operate within a wide temperature range, spanning from -40 to 45°C. At -40°C, the DIB exhibits exceptional performance, delivering 97.4% of its room-temperature capacity at 1C and displaying an extraordinarily high-rate discharge capability with 62.3% capacity retention at 10C. This study demonstrates a feasible strategy for the development of high-power and low-temperature rechargeable batteries.

Dilute Electrolytes with Fluorine-free Ether Solvents for 4.5 V Lithium Metal Batteries.

The limited oxidation stability of ether solvents has posed significant challenges for their applications in high-voltage lithium metal batteries (LMBs). To tackle this issue, the prevailing strategy either adopts a high concentration of fluorinated salts or relies on highly fluorinated solvents, which will significantly increase the manufacturing cost and create severe environmental hazards. Herein, an alternative and sustainable salt engineering approach is proposed to enable the utilization of dilute electrolytes consisting of fluorine (F)-free ethers in high-voltage LMBs. The proposed 0.8 M electrolyte supports stable lithium plating-stripping with a high Coulombic efficiency of 99.47% and effectively mitigates the metal dissolution, phase transition, and gas release issues of the LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode upon charging to high voltages. Consequently, the 4.5 V high-loading Li||NCM 811 cell shows a capacity retention of 75.2% after 300 cycles. Multimodal experimental characterizations coupled with theoretical investigations demonstrate that the boron-containing salt plays a pivotal role in forming the passivation layers on both anode and cathode. The present simple and cost-effective electrolyte design strategy offers a promising and alternative avenue for using commercially mature, environmentally benign, and low-cost F-free ethers in high-voltage LMBs.

Electrochemical CO2 Reduction to Multicarbon Products on Non-Copper Based Catalysts.

Electrochemical CO2reduction reaction (eCO2RR) to value-added multicarbon (C2+) products offers a promising approach for achieving carbon neutrality and storing intermittent renewable energy. Copper (Cu)-based electrocatalysts generally play the predominant role in this process. Yet recently, more and more non-Cu materials have demonstrated the capability to convert CO2into C2+, which provides impressive production efficiency even exceeding those on Cu, and a wider variety of C2+compounds not achievable with Cu counterparts. This motivates us to organize the present review to make a timely and tutorial summary of recent progresses on developing non-Cu based catalysts for CO2-to-C2+.We begin by elucidating the reaction pathways for C2+formation, with anemphasison the unique C-C coupling mechanisms in non-Cu electrocatalysts.Subsequently, we summarize the typical C2+-involved non-Cu catalysts, includingds-,d- andp-block metals, as well as metal-free materials, presenting the state-of-the-art design strategies toenhanceC2+efficiency. The system upgrading to promote C2+productivity on non-Cu electrodescoveringmicrobial electrosynthesis, electrolyte engineering, regulation of operational conditions, and synergistic co-electrolysis, is highlighted as well.Our review concludes with an exploration of the challenges and future opportunities in this rapidly evolving field.

Sustainable Production of Biofuels from Biomass Feedstocks Using Modified Montmorillonite Catalysts.

The rampant exploitation of fossil fuels has led to the significant energy scarcity and environmental disruption, affecting the sound momentum of development and progress of human civilization. To build a closed-loop anthropogenic carbon cycle, development of biofuels employing sustainable biomass feedstocks stands at the forefront of advancing carbon neutrality, yet its widespread adoption is mainly hampered by the high production costs. Montmorillonite, however, has garnered considerable attention serving as an efficient heterogeneous catalyst of ideal economic feasibility for biofuel production, primarily due to its affordability, accessibility, stability, and excellent plasticity. Up to now, nevertheless, it has merely received finite concerns and interests in production of various biofuels using montmorillonite-based catalysts. There is no timely and comprehensive review that addresses this latest relevant progress. This review fills the gap by providing a systematically review and summary in controllable synthesis, performance enhancement, and applications related to different kinds of biofuels including biodiesel, biohydrogenated diesel, levulinate, γ-valerolactone, 5-ethoxymethylfurfural, gaseous biofuels (CO, H2), and cycloalkane, by using montmorillonite catalysts and its modified forms. Particularly, this review critically depicts the design strategies for montmorillonite, illustrates the relevant reaction mechanisms, and assesses their economic viability, realizing sustainable biofuels production via efficient biomass valorization.

Nickel-doped CNTs composite as cathode by sulfur vapor deposition for high-performance all-solid-state lithium‑sulfur batteries

Shuttle effect of polysulfide in the cathode and the safety issues arising from dendrite formation at Li metal anode are the main challenges of traditional liquid lithium‑sulfur batteries. In order to solve the shuttle effect and prevent short circuit, the all-solid-state lithium‑sulfur battery (ASSLSB) is proposed. However, the huge volume expansion of sulfur and the improvement of sulfur conversion efficiency during charge and discharge, which could lead to the limitation of electrochemical performance. Herein, a homogeneous Ni-doped carbon-nanotubes (H-Ni-SVD@CNT) composite cathode of ASSLSB is prepared by sulfur vapor deposition to confine sulfur and promote the conversion of sulfur and Li2S. In this work, SVD-5-S@CNT composite cathode demonstrates high reversible discharge capacity of 1001.1 mAh g−1 after 127 cycles and capacity retention rate of 78.6 % at the rate of 0.1C and 60 °C. Moreover, H-Ni-SVD@CNT composite cathode exhibits superior electrochemical performance, displaying the discharge specific capacity of 1519.3 mAh g−1 at 0.1C and 60 °C. Meanwhile, the discharge specific capacity of H-Ni-SVD@CNT composite cathode is 1060.9 mAh g−1 at room temperature. The synergistic effect of physical confinement and chemical catalysis improves the electrochemical performance of the all-solid-state lithium‑sulfur battery. This work proposes a new strategy for the cathode structure design of the all-solid-state lithium‑sulfur battery.

Enhancing Thermal and Daylight Performance of Historic Buildings with Passive Modifications; A Tropical Case Study

Historical buildings worldwide hold immense potential for adaptive reuse within the framework of the circular economy, a concept gaining traction in the building construction industry for its role in reducing carbon emissions. Many of these structures boast passive building design strategies, which inherently lower energy demands. Among these, thermal mass and daylight harvesting emerge as pivotal strategies for achieving indoor thermal and visual comfort, respectively. However, with the advent of significant climate change and evolving built environments, the efficacy of these historical passive strategies is subject to debate. This study focuses on a residential building constructed in the 17th century by Dutch settlers in Galle, Sri Lanka, serving as a case study. The research targets improvements in both thermal and visual comfort. Thermal performance analysis was conducted through air temperature measurements, revealing a notable 3-hour time lag and a 2.5°C reduction in peak air temperature during the day. Conversely, nighttime measurements indicated a rise in indoor temperature compared to ambient conditions. Using Design Builder software, the building was modelled to assess its daylighting conditions. Drawing upon thermodynamic principles and daylight harvesting techniques, the study proposes building envelope interventions and ventilation strategies to address nighttime overheating and enhance daylight utilization. The results demonstrate that these modifications can potentially reduce nighttime heat by 2-3°C, while also decreasing the energy requirement for lighting comfort from 51.10 kWh/m² per annum to 44.84 kWh/m² per annum. This research showcases the effectiveness of judiciously implemented interventions in historical buildings, illustrating tangible improvements in both thermal/visual performance and energy efficiency. Leveraging inherent qualities of historical structures and integrating modern design strategies to these buildings can play a vital role in sustainable urban development and energy conservation efforts.

Architectural Preservation of Historic Buildings for Sustainable Built Environment

Preservation of historic buildings plays a crucial role in promoting sustainable environment by serving as a model for climate-responsive designs and bridge between the past and the present architecture. This study focused on the need for architectural preservation of historic buildings in order to explore their unique features for energy efficiency that can benefit the environment in a sustainable manner. The study relied on case study methodology. Intrinsic approach to case selection is adopted because of historical relevance and significance to sustaining the typical tropical architecture design characteristics. The design of this case study is guided by the thermal comfort and energy efficiency theoretical developments of tropical architecture. The features of investigation center around the design characteristics and strategies that enhance the livability of a typical tropical building. Data for this research is primarily sourced through direct observation and photographs. Analysis of the data is done thematically. Findings reveal the investigated case building possesses design strategies and characteristics for the prevention and removal of solar heat gains in tropical buildings. These would enhance sustainable architectural practices within the tropical climate of Nigeria

Development of strong, stiff and lightweight compression-resistant mechanical metamaterials by refilling tetrahedral wireframes

ABSTRACT Porous materials with excellent load-bearing capacity are essential for aerospace, shipbuilding, and biomedical devices where lightweight structures are required. In this study, a design strategy of mechanical metamaterials with a shell-based structure is proposed. By re-filling curved surfaces in the tetrahedral wireframe, closed cavities inside the structure are eliminated and the manufacturability is improved. The modified tetrahedron is mirrored, cut with specific proportions (25%, 50%, and 75%), and arrayed to form different structures. The compression performance of the structure is investigated using stereolithographic specimens and numerical methods. Compared with the mechanical metamaterials based on triply periodic minimal surfaces (TPMS) and strut-based structures, the new shell-based structures exhibit excellent strength and stiffness. The compressive strength and Young’s modulus of the structure with 50% cutting proportion are increased by 65% and 80%, respectively, compared with the Gyroid structure. This study offers a new design strategy for mechanical metamaterials with excellent compression-resistant capability.

Comprehensive Understanding of Elemental Doping and Substitution of Ni‐Rich Cathode Materials for Lithium‐Ion Batteries via In Situ Operando Analyses

This review explores the challenges and advancements in the development of high‐energy lithium‐ion batteries (LIBs), particularly focusing on the electrochemical and structural stability of Ni‐rich cathode materials. Despite their potential to increase the energy density of LIBs, these cathode materials encounter issues such as irreversible phase transitions and structural degradation during cycling, which ultimately affect their electrochemical performance. Elemental doping/substitution has emerged as promising strategies to address these challenges. However, the precise mechanisms underlying their performance enhancement remain unclear. The objective is to elucidate the complex reaction mechanisms triggered by doping and substitution in Ni‐rich cathode materials by employing in situ operando analyses to uncover their effects on electrochemical behavior and structural integrity during cycling. This comprehensive investigation aims to clarify the roles of elemental dopants or substituents in the crystal structures of Ni‐rich cathode materials, thereby offering valuable insights for the structural engineering of cathode materials in high‐energy LIBs. By elucidating these intricate mechanisms, this review provides a practical roadmap for future research and significantly contributes to LIB technology by guiding material design and optimization strategies in the development of advanced LIBs.

Impact of Urban Morphology on High-Density Commercial Block Energy Consumption in Severe Cold Regions

In sustainable city development, urban form plays an important role in block energy consumption, and as different environmental contexts and block functions create differences in energy use, it is necessary to study the relationship between morphology and energy consumption under the dual constraints of special environments and special block functions. Urban high-density blocks have concentrated energy consumption, high energy intensity, and complex morphological layout, but the influencing mechanism of the block’s morphology on its energy consumption remains unclear. Accordingly, this study focuses on the mechanism and evaluation method of the influence of morphology on the energy consumption of high-density commercial blocks in severe cold regions. Through Grasshopper model extraction, EnergyPlus performance simulation, Pearson correlation analysis, and linear regression analysis, this study extracts and classifies high-density commercial blocks in Harbin, China, into six basic layout types (Courtyard, Courtyard-T, Slab, Slab-T, Point, Point-T) according to their horizontal and vertical morphology, analyzes the energy consumption characteristics of each basic type, examines the relationships between energy use intensity (EUI) and building density (BD) and between floor area ratio (FAR) and building height standard deviation (BHSD), and constructs theoretical models by controlling variables to study the effect of a single form parameter on block EUI. The research findings are as follows: (1) The annual energy consumption of Point and Slab blocks is relatively low, whereas that of Courtyard and Courtyard-T blocks is higher due to the lack of open space in Courtyards and the poor ventilation in summer. (2) FAR is significantly correlated with the energy consumption of high-density commercial blocks in severe cold regions, while the effects of BD and BHSD are weaker than those of FAR. For every 0.1 increase in BD, every 1 increase in FAR, and every 1(m) increase in BHSD, the Winter Daily EUI of the Slab block changes by +0.87, −2.26, and −0.22 (kWh/m2), respectively, whereas that of the Slab-T block changes by −0.38, +0.68, and +0.08 (kWh/m2), respectively. (3) Controlling other variables, a large BD is theoretically beneficial to energy performance in the blocks, and increasing BD in the range of 0.4–0.55 has a significant effect on lowering energy consumption in Point blocks. EUI increases with the increase in FAR, while the change depends on different block types with the increase in BHSD. This study provides design strategies for high-density commercial blocks in severe cold regions. Under different layout types, though EUI shows different relationships with BD, FAR, and BHSD, Slab-T and Point-T blocks can achieve excellent energy performance by appropriately increasing BD and decreasing FAR, whereas Slab blocks need to decrease BD while increasing FAR. The patterns found in this paper can provide strategic help for policymaking and early urban design.

Flexible generation of structured terahertz fields via programmable exchange-biased spintronic emitters

Structured light, particularly in the terahertz frequency range, holds considerable potential for a diverse range of applications. However, the generation and control of structured terahertz radiation pose major challenges. In this work, we demonstrate a novel programmable spintronic emitter that can flexibly generate a variety of structured terahertz waves. This is achieved through the precise and high-resolution programming of the magnetization pattern on the emitter’s surface, utilizing laser-assisted local field cooling of an exchange-biased ferromagnetic heterostructure. Moreover, we outline a generic design strategy for realizing specific complex structured terahertz fields in the far field. Our device successfully demonstrates the generation of terahertz waves with diverse structured polarization states, including spatially separated circular polarizations, azimuthal or radial polarization states, and a full Poincaré beam. This innovation opens a new avenue for designing and generating structured terahertz radiations, with potential applications in terahertz microscopy, communication, quantum information, and light-matter interactions.

Charge generation by passive plant leaf motion at low wind speeds: design and collective behavior of plant-hybrid energy harvesters

Energy harvesting techniques can exploit even subtle passive motion like that of plant leaves in wind as a consequence of contact electrification of the leaf surface. The effect is strongly enhanced by artificial materials installed as ‘artificial leaves’ on the natural leaves creating a recurring mechanical contact and separation. However, this requires a controlled mechanical interaction between the biological and the artificial component during the complex wind motion. Here, we build and test four artificial leaf designs with varying flexibility and degrees of freedom across the blade operating on Nerium oleander plants. We evaluate the apparent contact area (up to 10 cm2 per leaf), the leaves’ motion, together with the generated voltage, current and charge in low wind speeds of up to 3.3 m s−1 and less. Single artificial leaves produced over 75 V and 1 µA current peaks. Softer artificial leaves increase the contact area accessible for energy conversion, but a balance between softer and stiffer elements in the artificial blade is optimal to increase the frequency of contact-separation motion (here up to 10 Hz) for energy conversion also below 3.3 m s−1. Moreover, we tested how multiple leaves operating collectively during continuous wind energy harvesting over several days achieve a root mean square power of ∼6 µW and are capable to transfer ∼80 µC every 30–40 min to power a wireless temperature and humidity sensor autonomously and recurrently. The results experimentally reveal design strategies for energy harvesters providing autonomous micro power sources in plant ecosystems for example for sensing in precision agriculture and remote environmental monitoring.

Construction and Electrochromic Properties of Two-Dimensional Covalent Organic Frameworks with Donor-Acceptor Structures of Triphenylamine and Bipyridine

Abstract The stacking between layers of a two-dimensional covalent organic framework (COF) leads to overlapping π orbitals, which enables charge carriers to be transported quickly through these pre-designed π orbitals. The two-dimensional COF featuring donor-acceptor interactions represents a straightforward approach for fabricating a high-performance organic electrochromic device. In this paper, N, N, N', N'-tetrad(4-aminophenyl)-1,4-phenylenediamine (TPDA) with electron-rich structure and 2,2'-bipyridine-5,5'-dialdehyde (BPDA) with strong electron absorption ability were used as the construction unit. COFTPDA-BPDA electrochromic materials with donor-acceptor structure were synthesized by Schiff base reaction, which can achieve reversible switching from red to dark gray. The color/fade time of the film at 474 nm wavelength is 6.8 s/11.9 s. The contrast retention rate of the film can reach 97.6% after 20 potential cycles, the memory time is as long as 4278 s. The present study demonstrates that constructing a donor-acceptor (D-A) structural unit with conjugated triphenylamine as the electron donor linked to bipyridine electron-withdrawing groups enhances charge transfer and redox reactions. With the success of this design strategy, the construction of the D-A structure is an important methodology for improving the electrochromic properties of materials.

A Long Tweak Goes a Long Way: High Multi-user Security Authenticated Encryption from Tweakable Block Ciphers

We analyze the multi-user (mu) security of a family of nonce-based authentication encryption (nAE) schemes based on a tweakable block cipher (TBC). The starting point of our work is an analysis of the mu security of the SCT-II mode which underlies the nAE scheme Deoxys-II, winner of the CAESAR competition for the defense-in-depth category. We extend this analysis in two directions, as we detail now. First, we investigate the mu security of several TBC-based variants of the counter encryption mode (including CTRT, the encryption mode used within SCT-II) that differ by the way a nonce, a random value, and a counter are combined as tweak and plaintext inputs to the TBC to produce the keystream blocks that will mask the plaintext blocks. Then, we consider the authentication part of SCT-II and study the mu security of the nonce-based MAC Nonce-as-Tweak (NaT) built from a TBC and an almost universal (AU) hash function. We also observe that the standard construction of an AU hash function from a (T)BC can be proven secure under the assumption that the underlying TBC is unpredictable rather than pseudorandom, allowing much better conjectures on the concrete AU advantage. This allows us to derive the mu security of the family of nAE modes obtained by combining these encryption/MAC building blocks through the NSIV composition method. Some of these modes require an underlying TBC with a larger tweak length than what is usually available for existing ones. We then show the practicality of our modes by instantiating them with two new TBC constructions, Deoxys-TBC-512 and Deoxys-TBC-640, which can be seen as natural extensions of the Deoxys-TBC family to larger tweak input sizes. Designing such TBCs with unusually large tweaks is prone to pitfalls: Indeed, we show that a large-tweak proposal for SKINNY published at EUROCRYPT 2020 presents an inherent construction flaw. We therefore provide a sound design strategy to construct large-tweak TBCs within the Superposition Tweakey (STK) framework, leading to new Deoxys-TBC and SKINNY variants. We provide software benchmarks indicating that while ensuring a very high security level, the performances of our proposals remain very competitive.

Temperature‐Responsive Polyoxometalates‐Based Materials: From Underlying Mechanism to Promising Applications

AbstractPolyoxometalates (POMs) are multifunctional anionic metal‐oxygen complexes with structural and electronic diversity, as well as tunable acid‐base and redox properties, resulting in their potential as building blocks for constructing temperature‐responsive polyoxometalates‐based materials (TRPMs). TRPMs represent a class of intelligent materials exhibiting property changes in response to temperature fluctuations, offering distinctive applications in various fields such as catalysis, medicine, sensors, imaging, and so on. Though many TRPMs are reported, a systematic review including recent advances is still absent. This review provides insights into recent advancements in temperature‐responsive mechanisms, nanostructure design strategies, and the characterization of TRPMs. Special emphasis is placed on enhancing the temperature‐responsive properties of TRPMs by incorporating POMs into suitable organic ligands, such as ionic liquid cations, deep eutectic solvent cations, cationic surfactants, and polymers. The incorporation of organic ligands with POMs not only enables temperature‐responsive phase transitions but also enhances other properties, such as catalyst selectivity and drug loading capacity, expanding TRPMs applications. Consequently, this review summarizes the applications of TRPMs in catalysis, drug delivery and release, and chemical sensing, as well as discusses future technological challenges. The in‐depth understanding of TRPMs may help in the design of TRPMs from the nanoscale, guiding and inspiring future development.

Biodegradable Ferroelectric Molecular Plastic Crystal HOCH2(CF2)7CH2OH Structurally Inspired by Polyvinylidene Fluoride.

Ferroelectric materials, traditionally comprising inorganic ceramics and polymers, are commonly used in medical implantable devices. However, their nondegradable nature often necessitates secondary surgeries for removal. In contrast, ferroelectric molecular crystals have the advantages of easy solution processing, lightweight, and good biocompatibility, which are promising candidates for transient (short-term) implantable devices. Despite these benefits, the discovered biodegradable ferroelectric materials remain limited due to the absence of efficient design strategies. Here, inspired by the polar structure of polyvinylidene fluoride (PVDF), a ferroelectric molecular crystal 1H,1H,9H,9H-perfluoro-1,9-nonanediol (PFND), which undergoes a cubic-to-monoclinic ferroelectric plastic phase transition at 339 K, is discovered. This transition is facilitated by a 2D hydrogen bond network formed through O-H···O interactions among the oriented PFND molecules, which is crucial for the manifestation of ferroelectric properties. In this sense, by reducing the number of -CF2- groups from ≈5000 in PVDF to seven in PFND, it is demonstrated that this ferroelectric compound only needs simple solution processing while maintaining excellent biosafety, biocompatibility, and biodegradability. This work illuminates the path toward the development of new biodegradable ferroelectric molecular crystals, offering promising avenues for biomedical applications.

Closed-form solutions for FPR-to-concrete bonded joints with loaded-end anchorage: Insight into the interfacial shear transferring mechanism

Incorporation of end anchorage has not only proven to be an effective method for enhancing the low utilization rate of the expensive fiber-reinforced polymer (FRP) material in the application of flexural strengthening of reinforced concrete (RC) beams but also improving the poor ductility and low load-bearing capacity of the FRP-to-concrete interface. The shear transfer mechanism at the interface with free-end anchorage has been understood, but for the interface with loaded-end anchorage, the shear transfer mechanism remains unclear. In this paper, a new analytical model is present to elucidate the shear transfer mechanism of the FRP-to-concrete bonded joint with loaded-end anchorage, including the U-jacket, FRP anchor, and mechanical fastener. The analytical solutions are presented and compared with the finite element analysis (FEA) results, and the good agreement between them verifies the accuracy of the proposed model. A comparison of the load-slip curves is conducted for the FRP-to-concrete bonded joint under various conditions, including scenarios without any anchorage, with free-end anchorage, and with loaded-end anchorage. Finally, design strategies are put forth for multiple anchorages to improve the load-bearing capacity and ductility of the FRP-to-concrete interface.

Jellyfish-inspired Polyurea Ionogel with Mechanical Robustness, Self-Healing, and Fluorescence Enabled by Hyperbranched Cluster Aggregates.

Ionogels are promising for soft iontronics, with their network structure playing a pivotal role in determining their performance and potential applications. However, simultaneously achieving mechanical toughness, low hysteresis, self-healing, and fluorescence using existing network structures is challenging. Drawing inspiration from jellyfish, we propose a novel hierarchical crosslinking network structure design for in situ formation of hyperbranched cluster aggregates (HCA) to fabricate polyurea ionogels to overcome these challenges. Leveraging the disparate reactivity of isocyanate groups, we induce the in situ formation of HCA through competing reactions, enhancing toughness and imparting the clustering-triggered emission of ionogel. This synergy between supramolecular interactions in the network and plasticizing effect in ionic liquid leads to reduced hysteresis of the ionogel. Furthermore, the incorporation of NCO-terminated prepolymer with dynamic oxime-urethane bonds (NPU) enables self-healing and enhances stretchability. Our investigations highlight the significant influence of HCA on ionogel performance, showcasing mechanical robustness including high strength (3.5 MPa), exceptional toughness (5.5 MJ m-3), resistance to puncture, and low hysteresis, self-healing, as well asfluorescence, surpassing conventional dynamic crosslinking approaches. This network design strategy is versatile and can meet the various demands of flexible electronics applications.