Advanced Materials最新文献

Long-term operation of hydrogels relies on protective coatings to avoid water swelling or evaporation, but these protections often cause substantial decreases in overall softness and stretchability. Here, a mechanically compatible seal with a coherent interfacial design is developed to encapsulate hydrogels. This seal is made from polybutylene (PIB) and polypropylene-graft-maleic anhydride (PP-g-MAH) blended poly(styrene-isobutylene-styrene) (SIBS). The PIB oligomers soften the SIBS networks, while the MAH groups facilitate covalent bonding between the SIBS and hydrogel. The sealed hydrogel exhibits an elastic modulus of 24 kPa and an elongation at a break of >1000%, both comparable to those of the pristine hydrogel. The adhesion energy between the seal and hydrogel reached >140 J m^-2 and can be further increased to >400 J m^-2 by a thermal treatment. This tough interface, together with the intrinsically low water vapor transmission rate of SIBS, allows the sealed hydrogel to maintain its modulus and stretchability after 10 days of drying in air. The sealed hydrogel is chemically and mechanically stable under harsh conditions, including acidic/alkaline/salty solutions, high temperatures, and cyclic mechanical deformation. This strategy applies to various hydrogels with diverse compositions and structures, leading to orders of magnitude improvements in the longevity of hydrogel-based electronic devices.

The integration of multiple flexible electronics is crucial for the development of ultra-flexible wearable and implantable devices. To fabricate an integrated system, robust and flexible bonding throughout the connection area, irrespective of the electrode or substrate, is needed. Conventional methods for flexible direct bonding have primarily been confined to metal electrodes or substrate-only bonding due to varying material properties. Consequently, the mechanical and electrical properties of the connections deteriorate based on their shape and size. This study introduces a bonding technique for wearable electronics, achieving strong, flexible connections between materials like gold and parylene at a low temperature (85 °C). This hybrid direct bonding method ensures strong bonding across both the Au electrode and parylene substrate within electronic interconnections. Additionally, a 3D-stacked flexible structure that maintains robustness and high flexibility without an adhesive layer is successfully developed. An ultrathin photoplethysmography sensor developed by stacking an ultrathin organic photodetector atop an organic light-emitting diode is demonstrated. Unlike traditional methods requiring adhesives or high pressure, this approach maintains flexibility essential for deformation, withstanding bending at a radius of 0.5 mm. The technique's robustness suggests promising applications in durable, ultra-flexible electronics integration.

Photosensitizer-assisted photocatalytic systems offer a solution to overcome the limitations of inherent light harvesting capabilities in catalysts. However, achieving efficient charge transfer between the dissociative photosensitizer and catalyst poses a significant challenge. Incorporating photosensitive components into reactive centers to establish well-defined charge transfer channels is expected to effectively address this issue. Herein, the electrostatic-driven self-assembly method is utilized to integrate photosensitizers into metal-organic frameworks, constructing atomically Ru-Cu bi-functional units to promote efficient local electron migration. Within this newly constructed system, the [Ru(bpy)₂]²⁺ component and Cu site serve as photosensitive and catalytic active centers for photocarrier generation and H₂O₂ production, respectively, and their integration significantly reduces the barriers to charge transfer. Ultrafast spectroscopy and in situ characterization unveil accelerated directional charge transfer over Ru-Cu units, presenting orders of magnitude improvement over dissociative photosensitizer systems. As a result, a 37.2-fold enhancement of the H₂O₂ generation rate (570.9 µmol g^-1 h^-1) over that of dissociative photosensitizer system (15.3 µmol g^-1 h^-1) is achieved. This work presents a promising strategy for integrating atomic-scale photosensitive and catalytic active centers to achieve ultrafast photocarrier transfer and enhanced photocatalytic performance.

Optically addressable solid-state spins are an important platform for practical quantum technologies. Van der Waals material hexagonal boron nitride (hBN) is a promising host as it contains a wide variety of optical emitters, but thus far observations of addressable spins have been sparse, and most of them lacked a demonstration of coherent spin control. Here, robust optical readout of spin pairs in hBN is demonstrated with emission wavelengths spanning from violet to the near-infrared. It is found that these broadband spin pairs exist naturally in a variety of hBN samples from bulk crystals to powders to epitaxial films, and can be coherently controlled across the entire wavelength range. Furthermore, the optimal wavelengths are identified for independent readout of spin pairs and boron vacancy spin defects co-existing in the same sample. These results establish the ubiquity of the optically addressable spin pair system in hBN across a broad parameter space, making it a versatile playground for spin-based quantum technologies.