Smart windows that can repel diverse liquids are highly attractive for the development of self-cleaning building system. Despite immense achievements having been made in drophobic smart windows, unfortunately, the limitations of inferior transparency, unsatisfactory flexibility, and scarce functionality greatly hinder their practical applications. Here, a multifunctional, all-flexible and slef-cleaning electrothermal-actuated (SETA) module with superior transparency is developed by sandwiching the hydrophobic SiO₂ nanoparticles decorated silver nanowires thin-film heater and the thermo-responsive hydrogel. Through loading/discharging an electric stimulus of 5 V, the optical visibility of SETA could be in situ switched between an opaque state (T₅₅₀ = 11.0%) and a transparent state (T₅₅₀ = 84.9%) relying on the dynamically collapsed and swollen transition of hydrogel on planar and three-dimensional curved surfaces. Moreover, SETA chipset is able to repel diverse liquids, including organic and inorganic species, showcasing an excellent self-cleaning capability. Lastly, all-in-one multifunctionalities, including pixelated display, thermal regulation, defogging, and self-cleaning on a single SETA chipset, are successfully deployed. Compared to the previous windows, the current SETA chipset is more competent for optical switching in reality, owing to its portable, energy-efficient, flexible, highly-transparent, and on-demand manipulating advantages. This work provides inspirations for self-cleaning greenhouse, tunable optics, intelligent vehicles, and so on.

Surface-enhanced Raman scattering (SERS) platform, which enables trace analyte detection, has important application prospects. By structuring/modifying the surface of the SERS substrate, analyte in highly diluted solutions can be concentrated into localized active areas for highly sensitive detection. However, subject to the difficulty of the fabrication process, it remains challenging to balance hot-spot construction and the concentration capacity of analyte simultaneously. Therefore, preparing SERS substrates with densely ordered hot spots and efficient concentration capacity is of great significance for highly sensitive detection. Herein, we propose an Ag and fluoroalkyl-modified hierarchical armour substrate (Ag/F-HA), which has a double-layer stacking design to combine analyte concentration with hotspot construction. The microarmour structure is fabricated by femtosecond-laser processing to serve as a superhydrophobic and low-adhesive surface to concentrate analyte, while the anodic aluminium oxide (AAO) template creates a nanopillar array serving as dense and ordered hot spots. Under the synergistic action of hot spots and analyte concentration, Ag/F-HA achieves a detection limit down to 10⁻⁷ M doxorubicin (DOX) molecules with a RSD of 7.69%. Additionally, Ag/F-HA exhibits excellent robustness to resist external disturbances such as liquid splash or abrasion. Based on our strategy, SERS substrates with directional analyte concentrations are further explored by patterning microcone arrays with defects. This work opens a way to the realistic implementation of SERS in diverse scenarios.

Small-scale electromagnetic soft actuators are characterized by a fast response and simple control, holding prospects in the field of soft and miniaturized robotics. The use of liquid metal (LM) to replace a rigid conductor inside soft actuators can reduce the rigidity and enhance the actuation performance and robustness. Despite research efforts, challenges persist in the flexible fabrication of LM soft actuators and in the improvement of actuation performance. To address these challenges, we developed a fast and robust electromagnetic soft microplate actuator based on a laser-induced selective adhesion transfer method. Equipped with unprecedentedly thin LM circuit and customized low Young's modulus silicone rubber (1.03 kPa), our actuator exhibits an excellent deformation angle (265.25°) and actuation bending angular velocity (284.66 rad·s⁻¹). Furthermore, multiple actuators have been combined to build an artificial gripper with a wide range of functionalities. Our actuator presents new possibilities for designing small-scale artificial machines and supports advancements in ultrafast soft and miniaturized robotics.

Diverse natural organisms possess stimulus-responsive structures to adapt to the surrounding environment. Inspired by nature, researchers have developed various smart stimulus-responsive structures with adjustable properties and functions to address the demands of ever-changing application environments that are becoming more intricate. Among many fabrication methods for stimulus-responsive structures, femtosecond laser direct writing (FsLDW) has received increasing attention because of its high precision, simplicity, true three-dimensional machining ability, and wide applicability to almost all materials. This paper systematically outlines state-of-the-art research on stimulus-responsive structures prepared by FsLDW. Based on the introduction of femtosecond laser-matter interaction and mainstream FsLDW-based manufacturing strategies, different stimulating factors that can trigger structural responses of prepared intelligent structures, such as magnetic field, light, temperature, pH, and humidity, are emphatically summarized. Various applications of functional structures with stimuli-responsive dynamic behaviors fabricated by FsLDW, as well as the present obstacles and forthcoming development opportunities, are discussed.