of dense hot-spots in SERS platforms provides high Raman signal enhancements, small interparticle distances (<10 nm) between the plasmonic structures should be realized. [10] Formation of hot-spots for SERS applications can be manipulated through different approaches, which are called as "Plasmonic Hot-Spot Engineering." [18,19] Traditional hot-spot engineering tools are fundamentally classified into two classes-bottom-up and top-down approaches. [20] Bottom-up techniques employ nanoparticles with plasmonic features. However, in these techniques, the uncontrolled aggregation of nanoparticles, insufficient strength of resulting hot-spots for sensing, and limited SERS active area lead to inconsistent field enhancement and SERS signals. [18] To overcome these problems, the top-

Herein, we demonstrated a strategy to control the folding ability of hydrogel platforms through pattern design and light illumination. Hydrogel platforms, which consist of a temperature-responsive colored pattern, a temperature-responsive intermediate layer, and a passive (nonresponsive) layer, were fabricated in molds with different geometries. Folding ability of the resulting films was manipulated by the light illumination, pattern design, and color. Furthermore, as a proof-of-concept, sample capturing from a target point was successfully demonstrated using the fabricated hydrogel platforms. These results show that our strategy may provide promising possibilities for the fabrication of the next-generation soft foldable materials.

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Soft actuators that draw inspiration from nature are powerful and versatile tools for both technological applications and fundamental research, yet their use in hot‐spot engineering is very limited. Conventional hot‐spot engineering methods still suffer from complexity, high process cost, and static generation of hot‐spots, thus, underperforming particularly in the application side. Herein, we demonstrate a strategy based on plasmonic nanoparticles decorated cilia‐inspired magnetic actuators that enable highly accessible millimeter‐sized hot‐spot generation via bending motion under a magnetic field. The hot‐spot formation is shown to be reversible and tunable, and leads to excellent Raman signal enhancements of up to ≈120 folds compared to the unactuated platforms. Accessible electromagnetic field magnification in the platforms can be manipulated by controlling magnetic field strength, which is further supported by finite difference time domain (FDTD) simulations. As a proof‐of‐concept demonstration, a centipede‐inspired robot is fabricated and used for sample collection/analysis in a target environment. Our results demonstrate an effective strategy in soft actuator platforms for reversible and tunable large‐area hot‐spot formation, which provides a promising guidance toward studying the fundamentals of hot‐spot generation and advancing real‐life plasmonic applications.

Engine numbers, which involve information regarding the engine type, production number, and year and place of manufacture, are used for identification purposes.Comprising of unique alphanumeric characters, the engine numbers are fully or partially obliterated especially in auto theft and smuggling cases to conceal the origin, identity, and owner of vehicles. The limitations of the current restoration techniques