ACS Materials Au最新文献

Over the past century, a growing body of work has demonstrated that cellular behavior is impacted by contact with the materials in the surrounding environment, at length scales from centimeters down to nanometers. Soft matter (such as native extracellular matrices) has historically been challenging to pattern with great precision, so early efforts to understand structured cell-material interactions in the 1990s took advantage of hard interfaces, leveraging fabrication methods developed for the electronics industry throughout the 60s and 70s. Ultimately, as it became clear that cells respond to not only topography and chemistry of their environment, but also mechanical properties, patterning methods have been extended to soft materials, although often with lower structural resolution. Here, we provide a historical overview of the development of structured cell scaffold interfaces, highlighting the potential for additional advances in material patterning translated from hard to soft matter.

The burgeoning field of 4D fabrication holds transformative potential in fabricating dynamic, tubular structures such as artificial vascular grafts, stents, and nerve conduits. These are critical for cardiovascular, respiratory, and neurological applications. Traditional 3D printing, despite its advances, remains constrained by the static nature of its structures, often resulting in challenges such as improper vascular integration, restricted endothelialisation in small-diameter grafts, and complex surgical deployment requirements. This perspective delves into the novel integration of stimuli-responsive smart materials that imbue printed structures with the ability to morph, repair, and adapt to specific environmental stimuli, facilitating a more biocompatible and physiologically relevant interface. Highlighting recent breakthroughs in vascular graft fabrication, we discuss the strategic use of multimaterial printing to achieve endothelial compatibility and structural fidelity. Moreover, advancements in bifurcated stents and multichannel nerve conduits underscore the role of self-assembling and self-folding mechanisms in addressing anatomical and biomechanical complexities inherent in regenerative medicine. However, the translational trajectory of 4D bioprinting is impeded by persistent issues like material scalability, stimulus precision control, mechanical stability, and stringent biocompatibility standards. Future research should prioritize the refinement of multifunctional biomaterials and the development of composite, stimuli-responsive scaffolds equipped with biosensor functionalities to better mimic the dynamic biomechanics of native tissues. This review provides an in-depth analysis of these challenges and explores pathways toward the clinical adoption of 4D-printed, biomimetic tubular structures, aiming to bridge the gap between experimental innovation and clinical application.

Lanthanide-containing nanocomposite hydrogels represent a versatile class of functional materials with significant potential for applications in chemical sensing, biomedicine, and information security. Diverse chemical strategies and design methodologies have been employed to tailor their structure-property-function relationships. In this perspective, we provide an overview of recent advancements in lanthanide-containing nanocomposite hydrogels, systematically categorized into five material-centric approaches, including upconversion nanoparticles, metal-organic frameworks, nanoclays, hydroxyapatite, and carbon-based nanomaterials. We summarize key developments in their composition, interfacial chemistry, and applications while also evaluating current challenges and outlining future research directions to guide the continued evolution of these hydrogel systems.

Aqueous batteries are sustainable energy storage solutions for next-generation grid energy storage. However, their practical deployment is limited by the narrow electrochemical stability window of water, which constrains cell voltage and leads to persistent performance degradation. In this Perspective, online electrochemical mass spectrometry is highlighted as a powerful operando technique for detecting and quantifying gas evolution in aqueous batteries. The fundamental principle and historical development of the technique are briefly reviewed, followed by a systematic evaluation of recent advances in applying the technique to study common gassing events in aqueous chemistries. Perspectives on leveraging the technique for high-sensitivity, high-accuracy, and high-throughput investigations of key cell components are offered, with the goal of accelerating the development of robust and commercially viable aqueous batteries.

Ionic skin is a fundamental platform for tactile sensors that utilize electrolytes as sensing components. Ionic liquids (ILs) are ideal for such applications because of their high ionic conductivities, wide potential windows, and negligible vapor pressures. However, their toxicity hinders their use in wearable, implantable, and environmentally sensitive devices. Herein, ionic gels are synthesized from a bioderived IL and comprise pyramidal microstructures that enhance their tactile sensing capability. These structures improve elasticity and reduce the intrinsic viscoelasticity of the gels. The optimized sensor exhibits two conductance sensitivities of 0.066 and 0.032 and capacitive sensitivities of 0.075 and 0.042 in the pressure ranges of 0-10 kPa and 10-50 kPa, respectively. It exhibits rapid response and relaxation times of 156 and 157 ms, respectively, and maintains sensing capabilities for more than 5000 mechanical cycles, with a change in the conductance of only 8.6%. The sensor degradation test revealed that the active componentsthe ionic gel and molybdenum (Mo) electrodesdegraded in phosphate-buffered saline within 133 days, whereas the substrate and encapsulation layer remained nondegradable under the tested conditions. These results demonstrate the potential of biodegradable, nontoxic tactile sensors prepared using bioderived ILs in healthcare monitoring, wearable electronics, and environmental sensing.

Mechanochemistry, old chemistry with new perspectives, has provided unprecedented opportunities for us to pursue a greener and more sustainable future, especially in the exploration of solid-state approaches toward the synthesis of functional nanomaterials. Chemical aging is another environmentally benign and low-energy-demand process that could be controlled precisely with solution environments. In this work, we combined these two approaches to design a mechanochemistry-driven and aging-controlled method for synthesizing nonstoichiometric bismuth oxide nanosheets, which demonstrated a great adsorption capacity and photocatalytic degradation performance toward forever chemicals. With thorough monitoring of the crystal structure and morphological and surface composition changes, the strain-to-defect transformations at the molecular-to-crystal level were proposed to be the dominant growth mechanism. The transient strain accumulation and relaxation from applied mechanical forces during grinding lead to defect-rich metallic bismuth bulk rod structures. The following chemical delamination, achieved through capping ligands and oxygen exposure during aging, produces defect-rich, nonstoichiometric Bi₂O_2.33 nanosheet structures. This proof-of-concept synthesis and proposed growth mechanism offer a different perspective toward 2D metal oxide nanosheet design and could help us better design a diverse library of functional nanomaterials through mechanochemistry and chemical aging.

Flexible humidity sensors have attracted widespread attention for their potential applications in telemedicine, motion detection, etc. Compared with conventional humidity sensors, flexible humidity sensors have advantages in flexibility, integration, and portability. However, reported flexible humidity sensors usually suffer from a low response, complex manufacturing processes, and poor stability. We fabricate a humidity sensor using a graphene/polymer composite as the sensitive material with a focus on improving the response and simplifying the manufacturing process. Then, we optimize the performance of the prepared flexible sensor by component design. The prepared flexible humidity sensor has a response of 1123%, and response and recovery times of 61.1/92.0 s, respectively, showing excellent humidity sensing performance. The human respiration, skin humidity field, and environmental humidity detection applications are successfully realized by the humidity sensor. Besides, the contactless gesture monitoring is accomplished by the humidity sensor array, demonstrating the potential for further development into healthcare and contactless human-machine interaction.

Bacterial nanocellulose (BNC) shows promise in sustainable materials science, but its insolubility limits broader applications. This study introduces a ternary deep eutectic solvent (TDES) composed of Choline Chloride, Imidazole, and Tannic acid to effectively dissolve BNC. The resulting solution exhibits enhanced bandgap energy, increasing from 4.348 to 4.528 eV (direct) and 4.156 to 4.471 eV (indirect), highlighting its potential application in a wide-bandgap semiconductor. Cyclic voltammetry revealed improved specific capacitance, indicating enhanced energy storage capacity. Its application in flexible soft material underscores its viability as a highly insulating yet sufficiently conductive material for future studies in biosensors, optoelectronics, and solar cells. By overcoming BNC's solubility challenges while enhancing TDES properties, this study advances biobased electronics and optical applications, paving the way for eco-friendly technological innovations.

The ferromagnetic shape memory (FSM) behavior of glass-coated Fe_47‑x Mn_24+x Ga₂₉ (x = 0-8 at. %) microwires has been investigated through temperature-dependent magnetization and ac magnetic susceptibility measurements. Magnetization measurements as a function of temperature reveal an abrupt increase and decrease in magnetization upon cooling and heating, respectively, indicating characteristic thermal hysteresis (ΔT _hys ) behavior typically associated with a magnetic-field-induced "diffusionless" martensitic transformation. The magnitude and width of ΔT _hys are strongly correlated with the Fe/Mn atomic ratio; notably, the Fe₄₅Mn₂₆Ga₂₉ microwire exhibits a very large ΔT _hys width of 98 K, which is attributed to local deformation involving the motion of Fe and Mn atoms. Furthermore, an antiferromagnetic transition is observed in a low-temperature region, shifting from 22 to 41 K depending on composition. This shift is attributed to variations in local exchange interactions arising from unequal occupation of Fe and Mn 3d orbitals. These findings highlight a compositionally driven design strategy that enables precise tuning of FSM behavior, making Fe-Mn-Ga microwires promising candidates for use in tunable magnetic actuation and sensing technologies.

The pursuit of advancements in energy storage is critical to making human activities more efficient and practical. Supercapacitors (SCs) are a promising alternative, offering high power density and long cycle life. The efficiency of these devices largely depends on the careful selection of materials for their electrodes and electrolytes. MXene, an emerging class of two-dimensional materials composed of transition metal carbides and nitrides, have shown significant potential as electrodes for energy storage devices. This review covers MXene electrodes in supercapacitors, integrating computational and experimental results. Based on the data from the reviewed literature, computational studies indicate capacitance values ranging from 8.19 μF/cm² to 3293.00 μF/cm² and from 252.2 F/g to 291.5 F/g. Experimental studies, in turn, report capacitance values from 26 F/g to 556 F/g and voltage windows reaching up to 1.4 V. The study explores their structural and electrical properties and their applicability in high-performance devices. Finally, we discuss the challenges in MXene research, highlighting current difficulties and providing insights into opportunities and future directions for developing more efficient energy storage solutions.