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ABSTRACT Atmospheric water harvesting (AWH) is a promising strategy to alleviate freshwater scarcity, with hygroscopic salts (e.g., LiCl) widely employed as active sorbents due to their high water affinity. However, practical deployment is hindered by the deliquescence of salts, which can lead to leakage, migration, and potential corrosion. Herein, we report a robust LiCl+CMC@cellulose composite foam fabricated via a scalable room‐temperature impregnation–drying strategy. By introducing carboxymethyl cellulose (CMC) as a polymeric stabilizer, we effectively immobilize LiCl within the cellulose scaffold through ionic coordination, suppressing salt aggregation and leakage. Benefiting from the hierarchical porous architecture of cellulose and this salt immobilization strategy, the optimized composite (treated by 15 wt% LiCl, 0.5 wt% CMC solution) achieves a high water uptake of 3.57 ± 0.15 g at 25°C and 90% relative humidity (RH) within 24 h, corresponding to 16.04± 0.82 g g⁻¹when normalized to pristine cellulose foam, representing a 15.4% enhancement over non‐stabilized counterparts. Crucially, the composite exhibits excellent durability, retaining 82.4% of its capacity after ten water uptake–release cycles. Furthermore, a spray‐coated carbon black (CB) surface layer enables rapid photothermal heating (up to 50.6°C under one sun irradiation), facilitating efficient solar‐driven water release. This integrated, environmentally benign design offers a low‐cost, durable platform for scalable, high‐performance AWH. 

Abstract Leveraging robot-assisted technology to manipulate tiny objects has shown significant potential in the fields of engineering, chemistry, and biology. However, achieving high-resolution, non-invasive manipulation of objects shielded by biological barriers remains a major challenge. In this work, we present a robot-assisted acoustic vortex end effector system capable of generating acoustic vortex beams for contactless manipulation of small objects. First, instead of generating a fixed acoustic vortex beam, our acoustic end effector can tune the chirality of the vortex beam by adjusting the topological charge number encoded in the holographic lens, allowing for customization of the size of the corresponding potential well to accommodate various sizes of trapped particle. Second, by leveraging acoustic vortex beams as a non-invasive manipulator, we successfully achieved acoustic manipulation through biomimetic barriers. In a proof-of-concept experiment, we demonstrated the high-resolution contactless acoustic manipulation of a plastic ball (3 mm diameter) within a straight phantom mimic-vessel. Third, by combining the acoustic vortex end effector with a real time ultrasound imaging system, our approach enables continuous, real-time monitoring of the entire acoustic manipulation process. This integration paves the way for acoustic trapping and manipulation in non-transparent environments. Overall, our research demonstrates the advantages of acoustic manipulation technologies in biomedical and clinical applications, offering a biocompatible solution for medical interventions in the future. 

Abstract The development of smart materials capable of dynamic shape morphing and rapid responsiveness has garnered significant interest for applications in soft robotics, tissue engineering, programmable materials, and adaptive structures. Hydrogels, owing to their intrinsic biocompatibility and flexibility, are promising candidates for such systems. Embedding micro-scale materials within hydrogel networks can further enhance their mechanical and functional properties. In this study, we present a hybrid fabrication platform that integrates surface acoustic wave (SAW)-based acoustofluidics with digital light processing (DLP) photopolymerization to fabricate smart hydrogel composites with programmable shape-memorable behavior. Using the SAW-induced acoustic potential field, silicon carbide (SiC) micro-whiskers are aligned within a custom UV-curable hydrogel ink and subsequently fixed via high-resolution DLP photopolymerization. This dual-control approach enables independent manipulation of micro-whisker orientation and structural geometry. Numerical simulations and Laser Doppler vibrometry-based validation were employed to characterize the acoustic field. To evaluate shape-memory behavior, the fabricated hydrogels were subjected to dehydration and rehydration cycles. The resulting shape transformations, driven by internal stress gradients within the aligned microparticle framework, enabled humidity-responsive actuation. This work establishes a novel strategy for constructing 4D-printed smart hydrogels, offering a versatile platform for the development of next-generation programmable materials and adaptive structures. 

Abstract Ultrasonics structural health monitoring (SHM) is widely recognized as an effective technique that enables early damage detection in large-scale structures and helps prevent potential catastrophic failures. Ultrasonic phased array technology has gained prominence in SHM due to its ability to inspect a large area with high spatial resolution. However, conventional systems often rely on physical wired sensor networks, limiting their deployment for hard-to-access regions. In this study, we present a wireless ultrasonic phased array system capable of dual-mode operation for both wall thickness measurement and structural damage detection. The system integrates wireless power transfer (WPT) modules and customized matching circuits, enabling efficient and flexible deployment. Proof-of-concept experiments demonstrate successful wall thickness evaluation and accurate defect localization in metallic structures using both delay-and-sum (DAS) and minimum variance (MV) imaging methods, with the MV algorithm offering improved imaging resolution. Future work will focus on advancing real-time monitoring through machine learning, enabling 3D imaging, and extending system applicability to anisotropic composite materials.