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Liquid metal phase change materials have the advantages of high thermal conductivity and high volumetric latent heat, which are expected to address the growing challenges of thermal management of advanced electronics. In previous studies, the effect of radiative heat transfer from fins of a phase change heat sink on thermal management performance has rarely been considered. In this study, radiative coating materials with high emissivity were prepared and coated on the fins of the liquid metal phase change heat sink. The effect of radiative heat transfer on the performance of liquid metal phase change heat sink was investigated. The experimental results of continuous heating under natural convection conditions show that the introduction of the radiative coating with an emissivity of 0.9298 can extend the time for the surface temperature of the heat source to reach 100 °C by 9.4%, while shortening the recovery time of the phase change heat sink by 14.9%. The results of high-power cyclic heating indicate that the high emissivity coating can reduce the peak temperature by 16.6 °C in the tenth working cycle. A simplified numerical model was subsequently developed and validated to determine the specific effects of phase change and radiative heat transfer on the overall thermal control performance. The radiation-enhanced liquid metal phase change heat sink proposed in this study is simple and maintenance-free. It is expected to address the thermal management issues of electronic devices that cannot use active cooling or operate in thin-air environments. [ABSTRACT FROM AUTHOR]

The large discrepancy among the nucleation kinetics extracted from experimental measurements and computer simulations and the prediction of the classical nucleation theory (CNT) has stimulated intense arguments about its origin in the past decades, which is crucially relevant to the validity of the CNT. In this paper, we investigate the atomistic mechanism of the nucleation in liquid Al in contact with amorphous substrates with atomic-level smooth/rough surfaces, using molecular dynamics (MD) simulations. This study reveals that the slightly distorted local fcc/hcp structures in amorphous substrates with smooth surfaces can promote heterogeneous nucleation through a structural templating mechanism, and on the other hand, homogeneous nucleation will occur at a larger undercooling through a fluctuation mechanism if the surface is rough. Thus, some impurities, previously thought to be impotent, could be activated in the homogeneous nucleation experiments. We further find that the initial growth of the nucleus on smooth surfaces of amorphous substrates is one order of magnitude faster than that in homogeneous nucleation. Both these factors could significantly contribute to the discrepancy in the nucleation kinetics. This study is also supported by a recent study of the synthesis of high-entropy alloy nanoparticles assisted with the liquid metal Ga [Cao et al., Nature 619, 73 (2023)]. In this study, we established that the boundary existed between homogeneous and heterogeneous nucleation, i.e., the structural templating is a general mechanism for heterogeneous nucleation, and in its absence, homogeneous nucleation will occur through the fluctuation mechanism. This study provides an in-depth understanding of the nucleation theory and experiments. [ABSTRACT FROM AUTHOR]

The thermophysical properties of liquid metals and alloys are crucial to explore the intrinsic mechanisms of the solidification process, glass formation, and fluid dynamics. The deep learning approaches have emerged as powerful tools in numerous scientific fields and exhibit extraordinary accuracy in the estimation of physical properties and structural characteristics for various materials. In this Tutorial, focusing on the thermophysical properties of liquid multicomponent alloys, deep learning methods, including both supervised learning and active learning, are introduced. Combined with the verification from electrostatic and electromagnetic levitation experiments, the influences of training parameters and methods on the accuracy to obtain interatomic potential by deep learning are revealed on the basis of deep neural network algorithm. As a result, this prediction method of liquid state properties for multicomponent alloys exhibited the dual advantages of high accuracy derived from density functional theory and low computational cost associated with empirical potential. [ABSTRACT FROM AUTHOR]

A model has been developed to predict the response of an eddy current flow meter (ECFM) to the passage of a non-conductive inclusion moving in a cylindrical tube filled with a liquid metal. The model can be solved analytically for small inclusion diameters and moderate AC frequencies of the excitation signal. This condition is expressed as v b S ω ≪ 1 , where v b is the dimensionless inclusion volume and S ω is a function of the ratio between the characteristic length of the system and the penetration depth of the magnetic field. The magnetic induction equation for this problem has also been solved numerically. A very good agreement between the analytical model and numerical solutions has been found for v b S ω ≪ 1. Two experimental setups have been designed. First, the ECFM model has been validated by comparing the response due to the passage of traveling beads of known diameters in a low melting point alloy. In a second experiment, the diameters of ascending argon bubbles have been estimated with the ECFM model. The numerical model predicts the gas volume with very good accuracy in the range of bubble diameters studied, between 1.5 and 6 mm, while the analytical model only deviates significantly from the experimental data when v b S ω ≳ 0.1. Moreover, we establish that the ECFM can also measure the radial deviation of the bubble trajectory, and the results are consistent with the theoretical limit for isolated bubbles between the regimes of oscillating/zigzag motion of ellipsoidal bubbles and non-oscillating motion of spherical bubbles. Another observation is that the dependence of the ECFM response on the shape of the bubble is negligible; indeed, the ECFM response is well approximated by a linear relation with the bubble volume as is assumed in the analytical model. Finally, an estimation of the terminal rising velocity of bubbles was also carried out. [ABSTRACT FROM AUTHOR]

In this work, we numerically investigate the impact of flowrate, sparger and reactor geometry on methane conversion in lab-scale cylindrical pyrolysis reactors embedding molten salts or metals. A multiscale approach is enforced, where a diffusion-reaction model yielding the conversion vs time within a single rising bubble is combined with the average residence time of gas bubbles obtained through the two-phase turbulent bubbly flow model. We find that the relative size of the sparger and the height-to-diameter ratio of the molten medium are key parameters for controlling the average residence time of the bubbles, which always results lower than that predicted by the terminal velocity of a single bubble rising in an overall static melt. The highest relative discrepancy (order 300%) between the single-bubble estimate and the CFD-based residence time is found in the case of molten salts in low-aspect ratio reactors fed by small spargers. The physical mechanism underpinning the influence of geometric parameters on the overall conversion is addressed in detail, together with the impact of two-phase flow effects on the estimation of bubble size in laboratory scale bubble reactors. • Multiscale approach developed for conversion vs. height in molten media pyrolysis reactors. • Effect of gas flow rate and reactor geometric characteristics on residence time assessed. • Turbulent motion of liquid causes decrease in residence time compared to stagnant liquid. • Proposed approach allows indirect measurement of bubble diameter from experimental conversion. [ABSTRACT FROM AUTHOR]

Global production of steel and aluminium is a major driver of greenhouse gas emissions. Various processes might allow continued primary production of the two metals, but all depend on emissions-free electricity or carbon storage, and global capacity of these two key resources will be below demand for decades to come. As a result, zero-emissions steel and aluminium will mainly come from recycling, but supply will be lower than demand. This motivates demand reduction, and for the first time, this article estimates the inefficiency in current metal use by component type. The results demonstrate that around 80% of steel and 90% of aluminium liquid metal produced today may be unnecessary. Around 40% of liquid steel and 60% of liquid aluminium are never used in final components as they are removed along the supply chain of manufacturing. Of the metal that enters final service, approximately one-third could be saved by avoiding component over-specification. A further third could be saved, where the properties of metal are not used to their limits. These results point to specific opportunities for innovation in design and manufacturing technology, of which the highest priority is to re-think the use of sheet metal in construction. This article is part of the discussion meeting issue 'Sustainable metals: science and systems'. [ABSTRACT FROM AUTHOR]

Dynamic liquid metal catalysts have remarkable activity and selectivity toward certain reactions, such as carbon dioxide reduction. The surface hydrogen coverage may play a role in this, including controlling competing reactions such as hydrogen evolution. Using a novel method of statistically selecting relevant snapshots from a dynamic liquid metal trajectory, the hydrogen adsorption energy is reported across liquid surfaces of Ga–Sn and Ga–In via density functional theory. A fully dynamic sampling of hydrogen adsorption to the liquid metal is also conducted with ab initio molecular dynamics at temperature. The results indicate that hydrogen only associates weakly with Ga–Sn and Ga–In surfaces, with minimal difference between the two materials. Hydrogen adsorbs only slightly more stably (≈0.1 eV) to the liquid surfaces compared to the solid. A low hydrogen coverage is predicted on the liquid metal of ≈0.03 H Å−2 at potentials of around –1.15 V (vs RHE). However, the mobility of hydrogen on the liquid surface is much greater due to a novel mechanism whereby the dynamic surface rearranges, opening pathways for diffusion. The results suggest that the unique catalytic behavior of these liquid metal materials may be due to changes in adsorbate diffusivity when the metals are melted. [ABSTRACT FROM AUTHOR]

In situ TiC ceramic particle-reinforced steel matrix composites, typically produced via liquid metal infiltration of unstructured preforms, often demonstrate issues with composite areas being prone to fracture. To address this problem, particles with an average diameter of 3 mm were constructed and used to fabricate preforms. Using the in situ self-generation method, the composites were then synthesised with liquid Mn18Cr2. To control the degree of in situ spontaneous reaction, moderator alloy powders at concentrations of 20, 30, 40 and 50 wt.% were utilised. The results reveal that the TiC particle size in the composites gradually decreases as the moderator concentration in the preform increases, reducing from 1.31 to 0.92 μm. The microhardness and elastic modulus at the composite interfaces are intermediate between those of the TiC ceramic particles and the high manganese steel matrix. The inclusion of millimetre-scale architecture enhances the tensile strength of the composites, with tensile strength gradually increasing as the moderator content decreases. This study offers a comprehensive understanding of how moderator content influences the microstructure and mechanical properties of TiC-reinforced Mn18Cr2 composites, providing valuable insights for the development of high-performance structural materials. [ABSTRACT FROM AUTHOR]

To address the significant commercial interest in fusion energy, it will be necessary to accelerate the compatibility research associated with liquid breeders including Li, eutectic Pb–Li and LiF-BeF2 (FLiBe) molten salt. Particularly for FLiBe, compatibility understanding is limited especially for fusion relevant materials such as reduced activation ferritic-martensitic steels, SiC and V alloys. The historical knowledge associated with molten salt reactors (MSRs) and recent work to commercialize MSRs can benefit fusion research. Recent experimental and modeling work has improved understanding and this knowledge can be applied to fusion relevant materials. For liquid metals (LMs), the comparisons to Li and Pb–Li are less direct but nevertheless can help guide the pathway toward commercialization. For Pb–Li, Al-rich coatings have been shown to inhibit dissolution and potentially increase operating temperatures. For commercialization, the experience with sensors and on-line cleanup can help guide future developments. Thus, it is worth considering the potential for fission-related research with LMs and molten salts to help accelerate fusion research. [ABSTRACT FROM AUTHOR]

The melting and motion of ferroalloys play a crucial role in the mass transfer and homogenization of molten steel in ladles. Heat transfer, melting, and solidification behavior of an alloy affect its size, thereby altering its motion within the gas-stirring ladle. This study established a heat transfer and solidification-melting model for alloy particles in high-temperature metal liquids. The computational fluid dynamics (CFD) method was used to simulate the fluid within the ladle, and the discrete element method (DEM) was employed for the alloy particles. This coupling approach elucidates the motion trajectories of different types of alloys in molten steel under flow and heat exchange, particle heating, melting, and shrinkage conditions. Furthermore, the effects of alloy size, initial alloy temperature, molten steel flow rate, and molten steel temperature on the melting behavior of different types of alloys were investigated. The results showed that the melting time exponentially increased with increasing alloy size or decreasing molten steel flow rate. Moreover, the alloy melting time decreased with increasing initial alloy temperature or molten steel temperature. The impact of these factors on the melting of FeCr, FeMn, FeSi, and Al alloys was also evaluated. Furthermore, FeSi and Al alloys added at different positions in the ladle with symmetric dual gas bottom blowing had a residence time of only 1 second in the molten steel and did not completely melt. These findings indicate that FeSi, Al, and FeCr alloys should be added at the 0.4R position in the symmetrical plane. Furthermore, the − 0.4R or − 0.2R positions are more favorable for the melting of FeMn. [ABSTRACT FROM AUTHOR]

Constant development of robotics forces scientists and engineers to work on robots that are more visually and rigidly compatible with the environment around us. To make this possible, new flexible structures are necessary that enable programmatic shape change. To meet this need, in this work we present the concept and modelling methodology of a new structure enabling shape change using electromagnetic forces produced in liquid metal conductor and its stiffening using a granular jamming mechanism. This work presents the structure concept, the description of modelling methodology and empirical validation including the magnetitic field, scanned by magnetic field camera, and displacement distribution. [ABSTRACT FROM AUTHOR]

Liquid metals (LMs) are opening large spaces for achieving functional 3D printing. However, previous fabrication strategies ever developed so far can only address a specific printing task that has yet to fulfill various needs. Conceiving that all fabrications and their output quality are dominated by the interactions between printing inks and their ambient environment, this review is dedicated to presenting a generalized framework toward the ubiquitous LM 3D printing and summarizing its fabrication category thus integrated. A panoramic view is provided that intentionally administrating the interfacial interactions among different media can guide ink modification and printing optimization. Further, the interactions between LM inks and various media are interpreted, ranging from gases, and liquids to soft matters, biological tissues, and even rigid materials, exploring key mechanisms such as oxidation facilitation, heat dissipation, structural support, modulus matching, strong wettability, and high reactivity. Following that, the LM inks, typical printing technologies, diverse working media, and enabled applications are reviewed. The elucidation of these interactions, particularly physical and chemical effects, can lead to the incubation of future LM 3D printing centers. It is expected that interactional LM 3D printing can mold additive manufacturing into ever‐powerful tools in the coming time. [ABSTRACT FROM AUTHOR]

Surface electrodes monitoring various electrophysiological activities with high sensitivity are crucial for studying electrical phenomena in living organisms. However, the sensitivity of current surface electrodes is limited due to electron transmission losses and signal attenuation at the electrode‐skin interface. Here, a bicontinuous liquid metal/polymer film electrode is developed, in which up to 92 wt.% of liquid metal is stably immobilized within a 3D continuous polymer network via electrostatic interactions. This electrode facilitates fast electron transport, enhances skin adhesion through hydrogen bonding, and ensures conformal contact due to its flexibility. As a result, the electrode achieves a sensitivity of 20 µV N−1, representing an improvement of 400% over the highest performance reported to date. This leap in sensitivity enables the high‐resolution monitoring of electrophysiological signals, allowing for earlier and more accurate identification of myocardial infarction abnormalities. Moreover, this high‐sensitivity electrode has the potential to develop an intelligent sensory system for material recognition and provide real‐time warnings in hazardous situations for individuals with tactile impairments. [ABSTRACT FROM AUTHOR]

The low‐temperature liquid metals Ga‐In and Ga‐Sn have previously showcased >95 % selectivity towards the electrochemical reduction of CO2 to formate, occuring only when the alloys are melted, not solid. Here, density functional theory molecular dynamics and metadynamics simulations reveal that CO2 does not directly adsorb to the Ga‐alloy surface, but instead is reduced indirectly by reaction with an adsorbed hydrogen. The reaction barrier is vastly more favourable when this process occurs at In or Sn sites (average: 0.26 eV), than when it occurs on Ga (average: 0.47 eV). However, there is no difference in barrier between solid and liquid surfaces. Instead, we find that Hads is mobile only on the liquid surface, travelling due to the motion of the liquid beneath. This process drives Hads to In/Sn sites, allowing low‐barrier CO2 reduction to occur only on the liquid. Therefore, the dynamic motion of liquid metal catalysts can underpin their unique reactivity. The result has far reaching implications for any protonation reaction conducted with a liquid metal catalyst. [ABSTRACT FROM AUTHOR]

The article contains the analysis of projection welding in relation to the non-parallel location (non-parallelism) of electrodes. For a thin-walled flat element, e.g., sheet metal with two embossed projections, calculations were conducted for different angles between the upper electrode and the lower electrode. The calculation involved the use of the SORPAS 3D software. The analysis included the distribution of temperature, power density, electrode displacement, the volume of molten metal in the weld nugget, nugget diameters, and energy supplied to the weld. The article presents the comparison of results obtained for various angles between the electrodes of the welding machine. The results of numerical calculations were verified experimentally through technological welding tests and destructive tests (peeling/metallographic). The convergence of the experimental and numerical results was satisfactory. The tests involved a typical element used in the automotive industry, i.e., a nut with two embossed projections in the flat part. The article represents quite an innovative new approach to multiple-projection welding from a numerical calculation point of view. Such an approach allows the researcher to identify the phenomena taking place in the process. The article also presents a new approach to the analysis of multi-projection welding as regards the non-parallelism of electrodes. The results enabled the determination of phenomena taking place in the multi-projection welding process as well as the boundary conditions in relation to which the process became improper (unstable). [ABSTRACT FROM AUTHOR]

In this study, the combined effect of Joule heating and Soret number on magnetohydrodynamics (MHD) braking of incompressible stratified liquid metal packed between a confined rotating annulus has been investigated. Both axial sinusoidal temperature and as well as sinusoidal concentration have been imposed in this braking system. However, radial cooling is enforced on the rotating disc of the braking system. The Soret effect on concentration gradient has been observed when the stratified liquid is exposed to a temperature gradient along with an axial magnetic field at different buoyancy ratios.A significant difference in convection heat and mass flow can be seen. The average shear wood decreased from 8.97 to 2.36 and the average Nusselt number decreased from 8.6 to 2.8 between the outer rotating disk and inner stationary disks at positive buoyancy ratios. This huge difference in heat and mass convection near the inner disk with respect to the outer brake disk confirms the MHD braking effect. Moreover, comparative studies of mass convection with respect to convective heat transfer have been observed based on the average magnitude of Sherwood and Nusselt numbers at both positive and negative buoyancy ratios. [ABSTRACT FROM AUTHOR]

Leveraging the fluidity and excellent conductivity of liquid metal (gallium‐indium alloy), liquid metal (LM) can be utilized to manufacture flexible and stretchable electronic products for applications in soft robotics, wearable devices, and human–machine interaction. However, the high surface tension and low surface adhesion of LM hinder its patterning and high‐resolution fabrication of soft electronics. Here a recyclable LM‐silicon dioxide (LMS) ink is proposed. Under stirring, silicon dioxide (SiO2) particles are encapsulated by the oxide layer of the LM, consuming the oxide layer. Meanwhile, gallium in the LM reacts with oxygen from the air to form a new oxide layer, enhancing the adhesion of the LM to the substrate while maintaining its conductivity. The in‐situ printing of LMS ink is verified on various materials (e.g., paper, polymer, and glass) with a resolution of up to 165 µm and an exceptional conductivity of ≈6.53 × 106 S m−1. The printed patterns can be erased with an anhydrous ethanol solution, allowing the recovered LMS ink to be reused for multiple writing cycles. The general method for direct LM circuits printing can fabricate various wearable sensors for soft electronic devices and human–machine interaction. [ABSTRACT FROM AUTHOR]

Liquid metal (LM)‐based magnetic fluids have attracted attention due to their rapid magnetic response, flexibility, and maneuverability. However, the nonwettability at the interface between metal particles and LM due to surface energy mismatch makes it challenging for metal particles to penetrate the LM oxide layer. Here, a strategy for mixing magnetic iron particles into LM through a reactive wetting mechanism is proposed. To address the inherent nonwettability at the interface between Fe particles and LM, FeGa2O4 is synthesized as a shell of Fe particles to enhance compatibility between Fe particles and LM. In particular, the wetting behavior of the FeGa2O4 shell on the interface between Fe@FeGa2O4 and LM is explained and validated based on the contact angle theory and density functional theory. Moreover, the mixture of Fe@FeGa2O4 particles into the LM enhances the rheological properties of the composite, effectively overcomes the inherent limitation of the low mechanical strength of LM, and improves the magnetic, electrical, and thermal properties of LM. Furthermore, studies on the adhesion mechanism of LM composites indicate that Fe@FeGa2O4 particles carrying more oxides into LM are crucial factors for adhesion. Given these notable advantages, LM‐based magnetic composites have shown tremendous potential in flexible electronics, soft robotics, and lightweight LM thermal interface materials. [ABSTRACT FROM AUTHOR]

Microfluidic--microwave devices (MMDs) have emerged as precision tools for the rapid, accurate, sensitive, and non-invasive characterisation of liquids in low-volumes. However, the fabrication of MMDs remains a significant challenge. This is due to the complexities associated with integrating fluidic ducts and electronic components. Herein, we present a versatile and economical 3D-printing approach using ducts filled with liquid metal as an electrical conductor. Cyclic olefin copolymer, polylactic acid, and polypropylene were identified as printable dielectric materials for MMD fabrication. Substrates of 3D-printed cyclic olefin copolymer exhibited the lowest loss tangent (0.002 at 2.7 GHz), making them suitable materials for highfrequency microwave devices. Liquid metal, specifically gallium--indium eutectic, was injected into the printed ducts to form electrically conductive microwave structures. Exemplary MMDs operating at 2 GHz integrated split-ring microwave resonators that serve as sensitive detection geometries able to measure changes in dielectric properties, with droplet-forming fluidic junctions and flow channels. The performance of 3D-printed MMDs for microwave droplet sensing was comprehensively evaluated. These devices were used in the formation and characterisation of water-in-oil emulsions, constructing definable lipidsegregated droplet interface bilayer (DIB) networks. This work indicates the feasibility of using 3D-printed manifolds for the rapid prototyping of customised MMDs, and also demonstrates the potential of MMDs as new analytical research tools in droplet-based materials and biochemistry studies. [ABSTRACT FROM AUTHOR]

With the continuous miniaturization and highly integrated development of modern electronics, thermal management materials with high thermal conductivity, good electrical insulating and flexibility are highly desired for the effective heat dissipation to maintain the reliable operations of electronic devices. However, enhancing thermal conductivity generally causes the deterioration of their mechanical properties and electrical insulation. Herein, combining the deformability of Galinstan-based liquid metal (LM) and good film-forming property of bacterial cellulose (BC), a series of thin and flexible boron nitride-based composite (BC/BNNS-LM) films was prepared via a facile vacuum-assisted filtration route. Benefiting from the directional arrangement of BNNS nanosheets, as well as gap-filling and bridging effects of deformable LM droplets, the resultant BC/BNNS-LM ternary nanocomposite film not only presents a high in-plane thermal conductivity of 66.1 W/m·K but also achieves excellent mechanical strength, flexibility and good dielectric property. These desirable properties confirm that the fabricated nanocomposite films have significant potential for effective heat dissipation in high-power-density electronics. [ABSTRACT FROM AUTHOR]

Transparent conducting oxides (TCOs) are crucial for high-performance displays, solar cells, and wearable sensors. However, their high process temperatures and brittle nature have hindered their use in flexible electronics. In this paper, we overturn these limitations by harnessing Cabrera-Mott oxidation to fabricate large-area, two-dimensional (2D) transparent electrodes via liquid metal printing. Our robotic, vacuum-free process deposits ultrathin (2–10 nm) indium tin oxide (ITO) with exceptional flexibility, transparency (>95%) and conductivity (>1300 S/cm) by utilizing hypoeutectic In-Sn alloys to print at <140 °C. Detailed characterization reveals the efficacy of Sn-doping and high crystallinity with large, platelike grains. The ultrathin nature enhances bending strain tolerance and scratch resistance, exceeding durability of PEDOT and offering low contact impedance to skin comparable to Ag/AgCl. We implement 2D ITO in synchronous, multimodal electrocardiography (ECG) and pulse plethysmography (PPG) measurements. This order-of-magnitude improvement to printed TCOs could enable wearable biometrics and display-integrated sensors. [ABSTRACT FROM AUTHOR]

Solid inorganics, known for kinetically inhibiting polymer crystallization and enhancing ionic conductivity, have attracted significant attention in solid polymer electrolytes. However, current composite polymer electrolytes (CPEs) are still facing challenges in Li metal batteries, falling short of inhibiting severe dendritic growth and resulting in very limited cycling life. This study introduces Ga62.5In21.5Sn16 (Galinstan) liquid metal (LM) as an active liquid alternative to conventional passive solid fillers, aiming at realizing self‐healing protection against dendrite problems. Compared to solid inorganics, for example silica, LM droplets could more significantly reduce polymer crystallinity and enhance Li‐ion conductivity due to their liquid nature, especially at temperatures below the polymer melting point. More importantly, LMs are unraveled as dynamic chemical traps, which are capable of blocking and consuming lithium dendrites upon contact via in situ alloying during battery operation and further inhibiting dendritic growth due to the lower deposition energy barrier of the formed Li‐LM alloy. As a proof of concept, by strategically designing an asymmetric CPE with the active LM filling, a solid‐state Li/LiFePO4 battery achieves promising full‐cell functionality with notable rate performance and stable cycle life. This active filler‐mediated self‐healing approach could bring new insights into the battery design in versatile solid‐state systems. [ABSTRACT FROM AUTHOR]

Reactive melt infiltration (RMI) is considered suitable process to prepare C/SiC composites with low porosity and near-net shape. However, because of inevitable reactions between molten metal and carbon fibers, mechanical properties of C/SiC composites may be affected. In this work, continuous TaC coating was successfully prepared on the surface of carbon fibers using molten salt method. Effects of temperature and holding time on microstructure, bonding configurations, and crystal structure of TaC coating were systematically investigated. With increase in temperature and time, TaC grains grew larger and TaC coating became thicker, with growth rate constant of about 3.05 × 10−17 m2/s. TaC coating prepared at 1200 °C for 60 min was continuous, uniform and well bonded with carbon fibers, and the main growth direction of TaC grains was [111]. Activation energy for formation of TaC coating was 295.48 kJ/mol. From a dynamic perspective, diffusion behavior of Ta ions through reaction interface was controlling step for formation of continuous TaC coating. [ABSTRACT FROM AUTHOR]

This investigation employs first‐principles calculations to explore the interaction between imidazolium ionic liquids (ILs) and fluoride additives on lithium metal surface. Our focus lies in the comprehensive analysis of three distinct categories of fluorinated additives, each differing in their degree of fluorination. The computations reveal that fluorination plays a significant role in determining both the ionic conductivity and the formation of the solid–electrolyte interphase (SEI) film. Specifically, heightened fluorination enhances the oxidative stability of the system but diminishes the strength of solvent binding, resulting in the formation of larger salt/anion clusters and a decrease in ionic conductivity. Conversely, increased fluorination facilitates the interaction between fluorinated additives and the lithium metal surface, thereby aiding in the formation of a stable SEI film characterized by an abundance of inorganic LiF components. This is important as it serves to suppress dendrite growth and mitigate interface side reactions. Considering the combined influences of ionic conductivity and film formation, 1FP is suggested as the optimal candidate for pyridine‐based additive systems, with FEC preferred for cyclic ester‐based additive systems and BC for chain ester‐based additive systems. This study provides theoretical references for the design of ionic liquid‐fluorinated additive electrolyte systems that can protect the lithium metal anode. [ABSTRACT FROM AUTHOR]

Additive manufacturing of metallic parts by Selective Laser Melting (SLM) implies high temperature gradients and small volume of the melt bath. These conditions make the process scales close to those available for state-of-the-art massively parallel atomistic simulations. In the paper, the microscopic mechanisms responsible for the formation of primary microstructure during molten metal solidification are investigated using classical molecular dynamics (CMD). The 316L austenitic stainless steel with face centred cubic lattice, which is widely used in industry including SLM applications was chosen as a material for the CMD simulations. It was shown that solidified material inherits substrate defects and catches new ones, which interact with the solidification front thus producing the primary microstructure. Peculiarities of solidification in different crystallographic directions and solidification front interaction with grain boundaries and newly produced defects (mostly twin boundaries) as well as their formation are under study. Resulting microstructures of virtual samples are compared with those of real samples produced by SLM and analysed by the electron backscatter diffraction (EBSD) method. The comparison shows similarities of EBSD and CMD sample patterns and evidences for the capability of the large-scale atomistic simulations to reproduce main features of the microstructures formed in the metallic SLM additive production. [ABSTRACT FROM AUTHOR]

Liquid metal (LM) elastomer composites offer promising potential in soft robotics, wearable electronics, and human‐machine interfaces. Direct ink write (DIW) 3D printing offers a versatile manufacturing technique capable of precise control over LM microstructures, yet challenges such as interfilament void formation in multilayer structures impact material performance. Here, a DIW strategy is introduced to control both LM microstructure and material architecture. Investigating three key process parameters–nozzle height, extrusion rate, and nondimensionalized nozzle velocity–it is found that nozzle height and velocity predominantly influence filament geometry. The nozzle height primarily dictates the aspect ratio of the filament and the formation of voids. A threshold print height based on filament geometry is identified; below the height, significant surface roughness occurs, and above the ink fractures, which facilitates the creation of porous structures with tunable stiffness and programmable LM microstructure. These porous architectures exhibit reduced density and enhanced thermal conductivity compared to cast samples. When used as a dielectric in a soft capacitive sensor, they display high sensitivity (gauge factor = 9.0), as permittivity increases with compressive strain. These results demonstrate the capability to simultaneously manipulate LM microstructure and geometric architecture in LM elastomer composites through precise control of print parameters, while maintaining geometric fidelity in the printed design. [ABSTRACT FROM AUTHOR]

The integration of electronics with the human body or wearables necessitates the evolution of energy storage devices capable of seamless adaptation to the conformability of the skin and textiles. This work focuses on developing an intrinsically stretchable electrode prepared by sedimenting the liquid metal particles in a conductive stretchable matrix. The liquid metal‐based electrode can be stretched to ≈900% strain, and its conductivity increases by extending to 250% and retaining its initial conductivity at 500% strain. Benefitting from these properties, the assembled all‐solid‐state energy storage device provides high stretchability of up to 150% strain and a capacity of 0.42 mAh cm−3 at a high coulombic efficiency of 90%. The charge storage mechanism is investigated by probing the electrode/electrolyte interface, uncovering the intricate gallium‐bis(trifluoromethane)sulfonimide (Ga‐TFSI) complexation during electrochemical cycling through in situ Raman spectroscopy, ex situ X‐ray photoelectron spectroscopy (XPS) analyses, and density functional theory (DFT) calculations. This work offers a promising avenue for the advancement of stretchable batteries. [ABSTRACT FROM AUTHOR]

Nanoscale structuring of gallium‐based liquid metals has emerged as a promising approach for generating unique properties and functionalities in advanced materials and devices. However, their exceptionally high surface tension presents significant challenges for achieving surface nanostructuring using conventional fabrication techniques. Here, a hypergravity nanoimprinting method is introduced, which harnesses horizontal centrifugation to generate hypergravity fields that drive liquid gallium into nanoscale cavities on an elastic polymer stamp surface at subzero temperatures, where it solidifies and preserves imprinted features down to 100 nm lateral resolution. This surpasses previous limits of gallium patterning, enabling phenomena such as iridescent structural colors with a wide range of hues and high saturation. Numerical simulations reveal the intricate fluid dynamic behaviors and interfacial interactions during the imprinting process, providing valuable insights for process optimization and control. By synergistically combining advanced soft lithography techniques with the reversible solid‐liquid phase transition properties of liquid metals, hypergravity nanoimprinting offers a practical nanofabrication approach, facilitating the development of next‐generation nanoscale gallium devices with finely structured nanofeatures across diverse application domains, such as nanoelectronics and photonic metamaterials. [ABSTRACT FROM AUTHOR]

Due to the excellent mechanical adaptability to curved surfaces and high circuit flexibility, conformal electronics have been developed for extensive applications including aeronautics and wearable electronics. However, conventional methods for fabricating conformal circuits are often constrained by planar structures, limiting the design flexibility and applicability of electronic devices on more complex and varied surfaces. Herein, a facial approach is proposed by combining a 3D‐printed customized conformal mask with liquid metal inkjet printing, to establish the completely conformal liquid alloy circuits' printing technique on arbitrary curved surfaces. A 2D transient mathematical model is developed to simulate the particle deposition process during inkjet printing and the form of the circuits on curved surfaces is predicted. Moreover, parameters such as line resistance and cross‐sectional morphology of liquid metal circuits on both deformable and nondeformable surfaces are characterized. Various conformal liquid metal circuits, such as contour lines, expressions, text patterns, light‐emitting diode (LED) array illumination patterns, and multichannel pressure array intelligent skin on curved surfaces, are demonstrated. Compared to traditional conformal electronics manufacturing methods, this new approach offers the advantages of simple process, flexibility, low cost (within $0.01 cm−2), and high efficiency (exceeding 1 cm2 s−1), making it suitable for mass conformal electronics production. [ABSTRACT FROM AUTHOR]

Excessive emissions of carbon dioxide (CO2) have caused the greenhouse effect and environmental crisis. Therefore, the carbon reduction and negative carbon technologies are particularly important. Among these, the negative carbon technologies that convert CO2 into carbon materials or carbon‐based chemicals for reuse have attracted significant attention. However, the strong double covalent bonds make the CO2 conversion usually require harsh conditions, complex processes, and high energy consumption. Gallium‐based liquid metals (LMs) are the functional materials with both metallic and liquid properties, exhibiting a unique liquid‐phase structure and diverse surface characteristics. Herein, a strategy for reducing CO2  is proposed to carbon materials by utilizing the spontaneous phase transition and mechanical friction of liquid metals. The gallium (Ga) and indium (In) particles are mixed and exposed to CO2, the contact interface of metal particles spontaneously transforms into liquid metals. The system has multistage interfaces, including Ga/In, Ga/eGaIn, and In/eGaIn, capable of generating triboelectrification upon mechanical stimulation, leading to charge transfer. The high electric field generated by friction at the contact interface directly reduces CO2 to carbon materials at room temperature. The carbon materials cover the surface of eGaIn and can be directly stripped for used as fuel, or industrial applications. [ABSTRACT FROM AUTHOR]

Soft strain sensors can accurately monitor the deformation of irregular and dynamic surfaces. However, traditional thin‐film strain sensors are generally not direction‐specific, and the sensor becomes unpredictable when stretched in different directions simultaneously. Here, a soft 1D strain sensor is reported that is only sensitive to axial deformation by rolling up a thin‐film strain sensor based on liquid metals (LM) and thermoplastic polyurethane (TPU) elastomer. The sensitivity of the 1D sensor can be regulated by rolling the 2D sensor at different angles. The 1D strain sensors have a large strain measuring range (>100%), high strain resolution (0.5%), fast responsiveness (<40 ms), and high reproducibility (over 2000 cycles), which are expected to adapt to various application scenarios with different sensitivity requirements. In addition, 1D strain sensors with different sensitivities can be braided into a three‐strand braid to provide measurements with three different sensitivities at the same time. [ABSTRACT FROM AUTHOR]

AbstractSelf-sustained movement has the ability to absorb energy from the external environment to maintain its own movement. In the present work, a self-sustained chaotic simple pendulum system featuring an electrothermal responsive liquid crystal elastomers fiber and a mass ball is proposed and examined. The power-on state is achieved in the system through the infusion of liquid metal into this fiber. Which enables the fiber to shrink, feeding energy into the system to compensate for the energy dissipation resulting from damping, thus allowing the system to maintain its self-sustained movement. On the basis of the existing dynamic liquid crystal elastomer model, the dynamic governing equations are established, and the movement behavior of the system under electrothermal stimulation is theoretically explored. Numerical findings suggest that the simple pendulum system presents three different movement patterns, namely stationary pattern, self-sustained oscillatory pattern, and self-sustained chaotic pattern. Moreover, five system parameters of elastic coefficient, viscosity coefficient, gravitational acceleration, shrinkage coefficient and electrothermal strength are examined. The present work can contribute to a better understanding of self-sustained chaotic systems driven by electrothermal responsive materials and offer guidance for further exploration of applications such as chaos machine, and mind-brain chaos analysis. [ABSTRACT FROM AUTHOR]

Gallium (Ga), a low‐melting‐point liquid metal with soft, metallic, and biocompatible properties, offers many possibilities. However, the potential of composites that integrate Ga with biomacromolecules, combining their biocompatibility, elasticity, and conductivity, has not been thoroughly explored, which is a gap for advancing these composites in various applications. In parallel and independently, protein self‐assembled l.,;3bhnanofibrils have attracted great interest as building blocks for functional biomaterials. Here, composites of Ga droplets and nanofibrils are presented, self‐assembled from plant proteins of soy protein isolate (SPI). It is evidenced that in these composites self‐assembled SPI nanofibrils can effectively reduce the oxidation of Ga droplets. It is observed that the composites of β‐sheet nanofibrils and Ga droplets offer mechanical properties similar to only fibrils‐based films. Films of 32 wt% Ga in SPI showed enhanced electrical conductivity and well‐structured nanofibrils with multifunctional potential in gas‐sensing and electronically controlled antibacterial applications. It is illustrated that the 32 wt% Ga in SPI composite offered the best sensing performance for a diatomic molecule, CO, and electro‐stimulation of this composite effectively reduced bacterial growth. The Ga in SPI composite, combining the advantages of protein nanofibrils and Ga droplets, offers great potential in future biomedical applications. [ABSTRACT FROM AUTHOR]

Organisms possess remarkably adaptive ability to complex environments. For example, chameleons can alter their skin color to adapt to varying environments, which has inspired significant advances in bioinspired soft electronic skins (E‐skins), and their wide applications in wearable sensors, intelligent robots, and health monitoring. However, current bioinspired E‐skins face challenges in ultra‐stretchability, high sensitivity, and long‐term stability owing to the intrinsic limitations associated with their mismatched interface between soft matrix and hard conductive fillers, hindering their practical applications. Here, it is reported that bioinspired structural color electronic skins (SC E‐skins) that consist of liquid metal particles (LMPs), periodical ordered colloidal crystal arrays, and ultra‐stretchable hydrogel, imparting synergistic and durable electrical–optical sensing capabilities. Such SC E‐skins demonstrate outstanding performances including superior flexibility (elongation at break > 1100%), high sensitivity (gauge factor = 3.26), fast synergetic electric–optical response time (≈100 ms), outstanding durability (over 1500 cycles), and high accuracy (R2 > 99.5%). These bioinspired SC E‐skins with excellent capability of converting mechanical signals into synergetic electrical–optical outputs hold great promise for smart wearable devices, affording a new horizon in developing advanced health monitoring technologies. [ABSTRACT FROM AUTHOR]

Gallium and gallium alloys have gained significant interest due to gallium's low melting point. This property allows for gallium‐based catalysts to take advantage of the unique reaction environments only available in the liquid state. While understanding of the catalytic properties of liquid metals is emerging, a comprehensive investigation into the fundamental structures of these materials has yet to be undertaken. Herein, the structure of liquid gallium, along with related liquid alloys EGaIn, EGaSn, and Galinstan are explored using X‐ray absorption spectroscopy (XAS). In contrast to some other studies that show dimers, analysis of the XAS data both in X‐ray absorption near edge structure and extended X‐ray absorption fine structure shows that when fully dissolved the materials are largely homogenous with no obvious signs of local structures. Ga shows a bond contraction when melted which is consistent with its increase in density; however, an expansion in bond length is observed when alloyed with In and Sn. XAS data indicate that the effective nuclear charge (Zeff) of In and Sn follows the trend expected based on electronegativity. Molecular dynamic (MD) simulations are performed to simulate the structure and trends between MD and XAS; the trends agree well but MD overestimates bond lengths. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) have garnered significant attention as efficient energy‐harvesting systems for sustainable energy sources in the field of self‐powered wearable devices. Various conductive materials are used to build wearable devices, among which, gallium‐based liquid metal (LM) is a preferred electrode owing to its fluidity and metallic conductivity even when strained. In this study, a stretchable, elastic, and wearable triboelectric nanogenerator is designed using a single electrode fabricated by embedding LM grid patterns into a stretchable silicone substrate through a two‐step spray‐coating process. Contrary to conventional double‐electrode TENG that is challenging to integrate to human body, the LM grid‐patterned single‐electrode TENG (LMG‐SETENG) has a simplified design and provides more flexibility. The LMG‐SETENG can generate voltages of up to 100 V via triboelectrification upon contact with the human body, even under various degrees of strain, owing to the fluidity of the LM electrode. The generated energy can be utilized as a sustainable energy source to power various small appliances. Moreover, the proposed LMG‐SETENG can be utilized in soft robotics, electronic skin, and healthcare devices. [ABSTRACT FROM AUTHOR]

Phase change materials (PCMs) offer promising solutions for efficient thermal management in electronic devices, energy storage systems, and renewable energy applications due to their capacity to store and release significant thermal energy during phase transitions. This study investigates the thermal and physical properties of Bi-In-Sn/WO3 composites, specifically for their use as phase change thermal interface materials (PCM-TIMs). The Bi-In-Sn/WO3 composite was synthesized through mechanochemical grinding, which enabled the uniform dispersion of WO3 particles within the Bi-In-Sn alloy matrix. The addition of WO3 particles markedly improved the composite's thermal conductivity and transformed its physical form into a putty-like consistency, addressing leakage issues typically associated with pure Bi-In-Sn alloys. Microstructural analyses demonstrated the existence of a continuous interface between the liquid metal and WO3 phases, with no gaps, ensuring structural stability. Thermal performance tests demonstrated that the Bi-In-Sn/WO3 composite achieved improved thermal conductivity, and reduced volumetric latent heat, and there was a slight increase in thermal contact resistance with higher WO3 content. These findings highlight the potential of Bi-In-Sn/WO3 composites for utilization as advanced PCM-TIMs, offering enhanced heat dissipation, stability, and physical integrity for high-performance electronic and energy systems. [ABSTRACT FROM AUTHOR]

This paper presents a simple, fast, and cost-effective method for creating metallic microstructured surfaces by spray-coating a dispersion of copper nanoparticles (CuNPs) onto polymethyl methacrylate (PMMA) substrates, enabling the imbibition-induced wetting of liquid metal. The formation of these microstructured patterns is crucial for the spontaneous wetting of gallium-based liquid metals. Traditional techniques for producing such microstructures often involve complex and costly lithography and vacuum deposition methods. In contrast, this study demonstrates that liquid metal wetting can occur with metal microstructures formed through a straightforward spray-coating process. To immobilize the CuNPs on the polymer substrate, an organic solvent that dissolves the polymer surface was employed as the dispersion medium. The effects of various spray-coating parameters, including distance and time, on the uniformity and immobilization of CuNP films were systematically investigated. Under optimal conditions (120 s of spray time and 10 cm spray distance), CuNPs dispersed in dichloromethane (DCM) yielded uniform and stable microstructured surfaces. The spontaneous wetting of gallium-based liquid metal was observed on the fabricated CuNP film. Additionally, liquid metal selectively wet the CuNP patterns formed by stencil techniques, establishing electrical connections between electrodes. These findings underscore the potential of spray-coating for fabricating metallic surfaces to drive the formation of liquid metal patterns in flexible electronics applications. [ABSTRACT FROM AUTHOR]

Background Mercury intake is caused by eating seafood, such as tuna and other predatory fish species. To reduce the health risks of mercury intake, it is necessary to continuously measure and monitor mercury concentrations at fish farms and markets. We have developed a compact system that can detect multiple heavy metals by liquid asymmetric-electrode plasma optical emission spectroscopy (LAEP-OES). Objective The validity of the LAEP-OES method for total mercury levels was evaluated using standard solutions, certified substances, and specimens of bluefin tuna and other fish species. Methods All specimens were dissolved in 4 M lithium hydroxide solution and then dispensed into a sample reservoir well of the single-use measurement reagent pack. Total mercury levels were automatically measured within 15 min of placement into the dedicated equipment. A total of 102 fish specimens, classified into 10 fish species, were evaluated using the new method and the results were compared to those obtained from validated analytical methods. Results LOD (0.02 mg/kg), LOQ (0.07 mg/kg), repeatability (4.0%), intermediate precision (9.8%), and trueness (recoveries 107%) of the proposed method were within satisfactory limits for total mercury levels in fish. Additionally, when using various fish species, the method had a strong positive correlation with the results of cold-vapor atomic absorption spectrometry (CV-AAS, the official method) with Spearman rs  = 0.984. Conclusion The LAEP-OES method can be used for measuring total mercury levels in bluefin tuna. Total mercury measurement using this new method has the potential to be applied to other fish species. Highlights Total mercury levels in fish were measured using our unique analysis system. Pacific bluefin tuna, southern bluefin tuna, and Atlantic bluefin tuna distributed in the Japanese market were analyzed for total mercury in their wild and farmed fish varieties. [ABSTRACT FROM AUTHOR]

Gas bubbling can be an effective means to float out alumina inclusions from liquid steel in a ladle. However, large spherical cap bubbles are formed when using porous plugs, as the liquid steel is nonwetting to the porous refractory. These bubbles rise rapidly through the liquid steel, forming a fast‐moving bubble plume, restricting contact times. Sized microbubbles, by contrast, have now been generated in liquid metals by shearing methods, involving linear crossflows to an entering flow of gas, or alternatively by rotational shearing. Combined with these convective shearing forces, local kinetic energy of turbulence can also play an important part in determining final microbubble size distributions. As microbubbles have much smaller rise velocities and present a far greater inclusion capture surface area than those of a single large bubble of the same gross volume, this will allow us to remove sub‐50 μm inclusions from liquid steel. It is expected that this goal will require a redesign of current ladle shrouds. [ABSTRACT FROM AUTHOR]

The Laser Directed Energy Deposition (LDED) technique in metal additive manufacturing (MAM) offers intricate geometries while maintaining material properties akin to cast and wrought components. However, challenges persist in fabricating high-strength aluminum alloys like 2xxx, 6xxx, and 7xxx series due to hot cracking during rapid solidification in LDED. This study addresses Al7075 hot cracking issue by introducing 1 wt% Zr. To evaluate this novel approach, the influence of process parameters on track geometry, porosity, microstructure, hardness, and tensile properties of both Al7075 and modified Al7075 (with 1 wt% Zr) was examined using an L27 orthogonal array of experiments. Findings indicate that increased laser power widens bead width and wetting angle. Conversely, higher scan speeds reduce bead height but marginally increase width, impacting wetting angle. Notably, the addition of Zr decreased porosity from 0.07 to 0.032%, indicating enhanced material quality. Microstructural analysis reveals Zr's role in preventing solidification cracking by enhancing molten metal fluidity during solidification, transitioning the microstructure from columnar to equiaxed fine grain due to Al3Zr precipitates, and promoting grain refinement. This addition of Zr also improved hardness and tensile strength by 11% and 10%, respectively, attributed to Al3Zr precipitates' role in grain refinement and precipitation strengthening within Al7075. In summary, incorporating 1 wt% Zr into Al7075 via LDED demonstrates promising improvements in microstructure, reducing porosity, enhancing mechanical properties, and mitigating solidification cracking, thereby offering potential enhancements in the fabrication of high-strength aluminum alloys. [ABSTRACT FROM AUTHOR]

Heat transfer characteristics in the electromagnetohydrodynamic flow of a third‐grade fluid between parallel plates have already been examined by researchers, but studies on the effect of temperature‐dependent viscosity on velocity, temperature, and heat transfer coefficients are very few. The present study investigates the heat transfer behavior of a third‐grade fluid flow between large parallel plates, taking temperature‐dependent viscosity when magnetic and electric fields are imposed externally. The plate walls are subjected to uniform temperatures. Consideration of temperature‐dependent viscosity results in the formulation of the phenomenon by nonlinear, coupled differential equations, which are solved by applying the least‐square method (LSM). Solving coupled, nonlinear equations by the LSM requires a great deal of modification in the implementation process. The obtained results in terms of dimensionless velocity are validated with the results of earlier studies and are also in a close match with the results of the Adomian decomposition method of the current study. Results indicate that for a higher value of the viscosity parameter, at first, velocity increases with an increase in the non‐Newtonian parameter. Beyond a certain value of the non‐Newtonian parameter, velocity starts reducing. Temperature, at all points of any cross‐section, increases up to a certain non‐Newtonian parameter and then reduces with the rise in the same parameter. For higher values of the viscosity parameter and low non‐Newtonian parameters, the upper plate requires an enhanced rate of cooling. Whereas, for higher values of the non‐Newtonian parameter at higher viscosity parameters, a lower heating rate is required. The results of the mathematical model can serve to be useful in the field of liquid metal flows in metallurgical industry, micropumps, medical and biological sectors, and microelectromechanical applications. [ABSTRACT FROM AUTHOR]

Conventional continuum robots have outstanding flexibility and dexterity. However, when the robot needs to interact with the environment, the softness may affect the performance of the robot. Especially in transport tasks, the softness of continuum robots can lead to handling failures and drastic drops in precision. The variable stiffness continuum robot combines the advantages of flexibility and rigidity, which is conducive to expanding the application scenarios of flexible continuum robots. This article proposes a flexible continuum robot that simultaneously realizes variable stiffness, shape‐aware, and self‐heating functions using liquid metal. The low‐temperature phase transition property of liquid metal is utilized to realize the variable stiffness function; the overall stiffness of the robot can reach the range of 18.5–183 N m−1, which can realize a tenfold stiffness gain. The conductivity of liquid metal is utilized to develop the shape‐aware function, and the monitoring accuracy is within 5%. At the same time, this article utilizes the liquid metal's resistive thermal effect to realize heating function, so that the robot no longer needs heating systems such as heating wires and can realize the phase transition by energizing itself. Based on this design, the robot arm can realize the transition between maximum and minimum stiffness within 240 s. [ABSTRACT FROM AUTHOR]

To advance the design space of electrically‐driven soft actuators, a flexible, architected soft robotic actuator is presented for motor‐driven extensional motion. The actuator comprises a 3D printed, cylindrical handed shearing auxetic (HSA) structure and a deformable, internal rubber bellows shaft. The actuator linearly extends upon applying torque from a servo motor; the rubber bellows shaft is stretchable but resistant to torsional deflection, allowing it to transmit torque from the servo motor to the other end of the HSA. The high flexibility of the HSA and rubber bellows shaft enable the actuator to adaptively extend even when bent. The actuator's two components and its performance are mechanically characterized. Actuation strains of 45% elongation and a maximum blocked pushing force of about 8 N are demonstrated. The actuator's capabilities are showcased in two separate demonstrations: a crawling robot and a sensorized artificial muscle that integrates a microfluidic, liquid metal strain sensor. The architected material design approach for a robust, motor‐driven soft actuator provides several unique features—including a compact form factor and ease of use—over other motorized soft robotic actuators based on HSA assemblies or cable tendon mechanisms. [ABSTRACT FROM AUTHOR]

The highly sensitive and power efficient tactile sensors can provide grippers with vertical and shear forces from interactions with objects. In an ocean environment with low visual distance and high noise, sea otters can rely on their palms to accurately identify and grasp target objects without damage. Inspired by the structure of the sea otter's palm, this paper proposes a distributed liquid metal-based three-dimensional biomimetic underwater triboelectric palm-like tactile sensor (UPTS) for feedback-controlled grippers. The device is mainly composed of a flexible shell, a flexible cover, a flexible support, a triboelectric sensing unit and a fixed shell. The force acting on the flexible cover causes the flexible cover and sensing unit to deform, so that the sensing unit undergoes a contact-separation process, thereby generating an electrical signal. UPTS has the capability to identify the magnitude and direction of force, with a direction recognition error angle within 5 degrees. Additionally, it can distinguish the hardness and shape of objects, achieving an accuracy rate of 100% and 99.75% respectively for the tested objects. The results indicate that UPTS can provide force feedback for underwater grippers, thereby assisting the grippers in better completing salvage task. [ABSTRACT FROM AUTHOR]

Soft sensors are flexible and stretchable, and because of this, they can be used on a wide range of surfaces, regardless of their size or shape. Such sensors may have applications such as in human–robot interaction, healthcare, soft robotics and human motion detection, where they can sense their surroundings and provide information. In this work, a soft piezoresistive sensor inspired by human finger ridges has been fabricated with liquid metal (EGaIn) electrode‐filled embedded microchannels on elastomeric material (Ecoflex 0030) and characterized for a pressure range of 0 to 280 kPa at different compression rates. The sensitivity of the elastomeric sensor increases and the limit of detection (LOD) decreases with a reduction in compression rate. In this work, microchannels on soft and stretchable elastomers are cast on a metallic mold prepared using the micromilling method. This method reduces the complexity of developing microchannels on the soft material using the metallic mold. The sensor has microchannels with a cross‐section of 200 μm × 200 μm, an active sensing area of 10 × 10 mm2 and overall dimensions of 15 × 15 × 2 mm3. At a low compression rate, this sensor exhibits a maximum sensitivity of 0.126 kPa−1 and a high linearity of 0.98, a LOD of 68 Pa, a response time of 30 ms and stability for 10 000 consecutive cycles at 100 kPa load. The developed sensor was shown to successfully differentiate various objects (soft to hard) based on the feedback it received when it was deployed on the gripper of an industrial manipulator. © 2024 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

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Water stability is one of the most important factors restricting the practical application of metal organic frameworks (MOFs). In this work, we fabricate a highly defective HKUST-1 framework with a mixed valence of CuI/CuII by mechanical ball milling method. This defective HKUST-1 is embellished by functionalized ionic liquids as hydrophobic armor, making the hybrid HIL1@HKUST-1 exhibits outstanding water stability, remarkable SO2 adsorption (up to 5.71 mmol g-1), and record-breaking selectivity (1070 for SO2/CO2 and 31,515 for SO2/N2) at 25 °C and 0.1 bar, even in wet conditions. [ABSTRACT FROM AUTHOR]

Highlights: Unique inter-skeleton conductive films are constructed in polymer foam. The resistance change of the foam can reach four orders of magnitude under compression. This foam exhibits strain-adaptive electromagnetic interference shielding performance, anti-interference pressure sensor with high sensitivity over a wide pressure range and compression-regulated Joule heating function. Conductive polymer foam (CPF) with excellent compressibility and variable resistance has promising applications in electromagnetic interference (EMI) shielding and other integrated functions for wearable electronics. However, its insufficient change amplitude of resistance with compressive strain generally leads to a degradation of shielding performance during deformation. Here, an innovative loading strategy of conductive materials on polymer foam is proposed to significantly increase the contact probability and contact area of conductive components under compression. Unique inter-skeleton conductive films are constructed by loading alginate-decorated magnetic liquid metal on the polymethacrylate films hanged between the foam skeleton (denoted as AMLM-PM foam). Traditional point contact between conductive skeletons under compression is upgraded to planar contact between conductive films. Therefore, the resistance change of AMLM-PM reaches four orders of magnitude under compression. Moreover, the inter-skeleton conductive films can improve the mechanical strength of foam, prevent the leakage of liquid metal and increase the scattering area of EM wave. AMLM-PM foam has strain-adaptive EMI shielding performance and shows compression-enhanced shielding effectiveness, solving the problem of traditional CPFs upon compression. The upgrade of resistance response also enables foam to achieve sensitive pressure sensing over a wide pressure range and compression-regulated Joule heating function. [ABSTRACT FROM AUTHOR]