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Abstract: Flexible smart surfaces with tunable wettability are promising for emerging wearable uses. However, currently, wearable superhydrophobic surfaces with dynamic wetting behaviors are rarely reported. Here, a skin‐like superhydrophobic elastomer surface with switchable lotus leaf and rose petal states is reported. Direct laser writing technique is employed for one‐step, programmable, large‐scale fabrication of monolithic and hierarchical micro‐nanostructures on elastomer, leading to strong water repellence. The surface topography can be finely regulated in a rapid and reversible manner by simple stretching, providing the feasibility of controlling the surface wettability by simple body motions. The ability to switch wetting states enables the surface to capture and release multiple droplets in parallel. Furthermore, the active surface can be applied to the joints of fingers and operate as a droplet manipulator under finger motions without requiring energy supply or external appliance. In this work, dynamic tuning of wetting properties is integrated into the design of skin‐like wearable surfaces, revealing great potential in versatile applications such as wearable droplet manipulator, portable actuator, adaptive adhesion control, liquid repellent skin, and smart clothing. [ABSTRACT FROM AUTHOR]

In the development of microfluidic chips, conventional 2D processing technologies contribute to the manufacturing of basic microchannel networks. Nevertheless, in the pursuit of versatile microfluidic chips, flexible integration of multifunctional components within a tiny chip is still challenging because a chip containing micro-channels is a non-flat substrate. Recently, on-chip laser processing (OCLP) technology has emerged as an appealing alternative to achieve chip functionalization through in situ fabrication of 3D microstructures. Here, the recent development of OCLP-enabled multifunctional microfluidic chips, including several accessible photochemical/photophysical schemes, and photosensitive materials permiting OCLP, is reviewed. To demonstrate the capability of OCLP technology, a series of typical micro-components fabricated using OCLP are introduced. The prospects and current challenges of this field are discussed. [ABSTRACT FROM AUTHOR]

The rapid progress of microfluidics has contributed to modern analytical methodology. However, in situ integration of chemical/biological sensors for on‐chip reaction monitoring remains a big challenge. Herein, reported is the fabrication of an integrated surface‐enhanced Raman scattering (SERS) sensor and graphene‐based catalytic chip by laser scribing of graphene oxide (GO) and Ag nanoparticles (AgNPs) composite (AgNPs@GO). The surface plasmonic effect of AgNPs can promote the photoreduction of GO, inducing a high porous nanostructure. By combining the AgNPs@RGO nanocomposite patterns with polydimethylsiloxane microfluidic channels, a bi‐functional microfluidic chip capable of on‐chip catalysis and SERS detection is fabricated. As a proof‐of‐concept demonstration, on‐chip AgNPs‐catalyzed 4‐nitrophenol (4‐NP) reduction has been implemented, in which the reaction process can be well monitored using the in situ SERS sensor. The integration of SERS sensors with functional microfluidic devices may hold great promise for developing advanced Lab‐on‐a‐Chip systems. [ABSTRACT FROM AUTHOR]

We report controllable assembly of silver nanoparticles (Ag NPs) for patterning of silver microstructures. The assembly is induced by femtosecond laser direct writing (FsLDW). A tightly focused femtosecond laser beam is capable of trapping and driving Ag NPs to form desired micropatterns with a high resolution of ∼190 nm. Taking advantage of the ‘direct writing’ feature, three microelectrodes have been integrated with a microfluidic chip; two silver-based microdevices including a microheater and a catalytic reactor have been fabricated inside a microfluidic channel for chip functionalization. The FsLDW-induced programmable assembly of Ag NPs may open up a new way to the designable patterning of silver microstructures toward flexible fabrication and integration of functional devices. [ABSTRACT FROM AUTHOR]