Thermo-Induced Biomimetic Switchable Slippery Interfaces with Strong Dual-Phase Adhesion via Femtosecond Laser Fabrication.

Smart surfaces with switchable adhesion have garnered significant attention in wearable devices, robotics, and biological detection. However, achieving universal switchable adhesion at both solid and liquid interfaces is still challenging. Here, we report a thermo-induced biomimetic switchable slippery interface (TBSSI) with robust solid and liquid adhesion, inspired by octopus tentacles and slippery mussels.

Synergistic binding ability of electrostatic tweezers and femtosecond laser-structured slippery surfaces enabling unusual droplet manipulation applications.

We propose a novel contactless droplet manipulation strategy that combines electrostatic tweezers (ESTs) with lubricated slippery surfaces. Electrostatic induction causes the droplet to experience an electrostatic force, allowing it to move with the horizontal shift of the EST. Because both the EST and the slippery operating platform prepared by a femtosecond laser exhibit a strong binding effect on droplets, the EST droplet manipulation features significant flexibility, high precision, and can work under various operating conditions.

Portable Triboelectric Electrostatic Tweezer for External Manipulation of Droplets within a Closed Femtosecond Laser-Treated Superhydrophobic System.

Controllable droplet manipulation has diverse applications; however, limited methods exist for externally manipulating droplets in confined spaces. Herein, we propose a portable triboelectric electrostatic tweezer (TET) by integrating electrostatic forces with a superhydrophobic surface that can even manipulate droplets in an enclosed space. Electrostatic induction causes the droplet to be subjected to an electrostatic force in an electrostatic field so that the droplet can be moved freely with the TET on a superhydrophobic platform.

Multifunctional Electrostatic Droplet Manipulation on the Femtosecond Laser-Prepared Slippery Surfaces.

A strategy to manipulate droplets on the lubricated slippery surfaces using tribostatic electricity is proposed. By employing femtosecond laser-induced porous microstructures, we prepared a slippery surface with ultralow adhesion to various liquids. Electrostatic induction causes the charges within the droplet to be redistributed; thus, the droplet on the as-prepared slippery surfaces can be guided by electrostatic force under the electrostatic field, with controllable sliding direction and unlimited transport distance.

Unraveling the influence of biogenic volatile organic compounds and their constituents on ozone and SOA formation within the Yellow River Basin, China.

Biogenic volatile organic compounds (BVOC) assume a pivotal role during the formation stages of ozone (O) and secondary organic aerosols (SOA), serving as their primary precursors. We used the latest MEGAN3.1 model, updated vegetation data and emission factors, combined with MODIS data analysis to simulate and estimate the integrated emissions of BVOC from nine provinces in China's Yellow River Basin in 2018.

Durable Janus membrane with on-demand mode switching fabricated by femtosecond laser.

Despite their notable unidirectional water transport capabilities, Janus membranes are commonly challenged by the fragility of their chemical coatings and the clogging of open microchannels. Here, an on-demand mode-switching strategy is presented to consider the Janus functionality and mechanical durability separately and implement them by simply stretching and releasing the membrane. The stretching Janus mode facilitates unidirectional liquid flow through the hydrophilic micropores-microgrooves channels (PG channels) fabricated by femtosecond laser.

Self-Driving Underwater "Aerofluidics".

Here, the concept of "aerofluidics," in which a system uses microchannels to transport and manipulate trace gases at the microscopic scale to build a highly versatile integrated system based on gas-gas or gas-liquid microinteractions is proposed. A kind of underwater aerofluidic architecture is designed using superhydrophobic surface microgrooves written by a femtosecond laser. In the aqueous medium, a hollow microchannel is formed between the superhydrophobic microgrooves and the water environment, which allows gas to flow freely underwater for aerofluidic devices.

Emerging Separation Applications of Surface Superwettability.

Human beings are facing severe global environmental problems and sustainable development problems. Effective separation technology plays an essential role in solving these challenges. In the past decades, superwettability (e.

Water/gas separation based on the selective bubble-passage effect of underwater superaerophobic and superaerophilic meshes processed by a femtosecond laser.

To solve the problems caused by tiny bubbles in liquids and the difficulties involved in collecting useful gas underwater, this paper proposes a method to separate bubbles from water by integrating underwater superaerophobic and superaerophilic porous membranes, including bubble removal and collection methods. Inspired by fish scales and lotus leaves, underwater superaerophobic microstructures and underwater superaerophilic microstructures are prepared on a stainless steel (SS) mesh by femtosecond laser processing, respectively. The as-prepared underwater superaerophobic mesh has an anti-bubble ability, while the underwater superaerophilic mesh has a bubble-absorption ability in water.

Magnetically Controllable Isotropic/Anisotropic Slippery Surface for Flexible Droplet Manipulation.

Controllable wetting surfaces play a significant role in numerous applications such as smart liquid manipulation, lab-on-a-chip, drug delivery, liquid robot, and so on. A novel type of magnetically controllable isotropic/anisotropic slippery surface was prepared by femtosecond laser ablation. The slippery liquid-infused porous surface (SLIPS) can be switched between an isotropic smooth state and an anisotropic groove state by the magnetic field.

A femtosecond Bessel laser for preparing a nontoxic slippery liquid-infused porous surface (SLIPS) for improving the hemocompatibility of NiTi alloys.

A slippery liquid-infused porous surface (SLIPS) is able to improve the hemocompatibility of implantable medical materials, which have saved countless lives. However, the preparation of a SLIPS on an implantable metal substrate (especially NiTi alloys) is still a substantial challenge because of the great difficulty of forming abundant porous microstructures on hard metals. In this paper, a novel strategy to prepare a SLIPS on a NiTi alloy substrate is reported.

Mini-Review on Bioinspired Superwetting Microlens Array and Compound Eye.

Microlens arrays (MLAs) and MLA-based artificial compound eyes (ACEs) are the important miniaturized optical components in modern micro-optical systems. However, their optical performance will seriously decline once they are wetted by water droplets (such as fog, dew, and rain droplets) or are polluted by contaminations in a humid environment. In this mini-review, we summarize the research works related to the fabrication of superwetting MLAs and ACEs and show how to integrate superhydrophobic and superoleophobic microstructures with an MLA.

Relationship and Interconversion Between Superhydrophilicity, Underwater Superoleophilicity, Underwater Superaerophilicity, Superhydrophobicity, Underwater Superoleophobicity, and Underwater Superaerophobicity: A Mini-Review.

Superwetting surfaces have received increasing attention because of their rich practical applications. Although various superwettabilities are independently achieved, the relationship between those superwettabilities is still not well-clarified. In this mini-review, we show that superhydrophilicity, underwater superoleophilicity, underwater superaerophilicity, superhydrophobicity, underwater superoleophobicity, and underwater superaerophobicity can be obtained on a same structured surface by the combination of hierarchical surface microstructures and proper chemistry.

Femtosecond Laser Microfabrication of Porous Superwetting Materials for Oil/Water Separation: A Mini-Review.

Frequent oil-leakage accidents and large quantities of oil-bearing wastewater discharge cause severe environmental pollution and huge economic losses. Recently, superwetting porous materials are successfully utilized to separate oil/water mixture (OWM) based on the different interfacial behavior of water and oil. Here, we summarize the recent development of efficient oil/water separation (OWS) based on the femtosecond laser-induced superwetting materials.

Filtration and removal of liquid polymers from water (polymer/water separation) by use of the underwater superpolymphobic mesh produced with a femtosecond laser.

The widespread use of liquid polymers may pollute water, causing grave environmental problems and even various human diseases. The separation of a mixture of a liquid polymer and water is extremely important in research, but the high viscosity, low fluidity, and high adhesion performance of liquid polymers make this task highly challenging. In this paper, we propose a novel strategy for separating a polymer/water mixture wherein porous underwater superpolymphobic micro/nanostructures are used for the first time.

Femtosecond laser hybrid fabrication of a 3D microfluidic chip for PCR application.

Microfluidic chips have gradually become a focus of scientific research. However, the fabrication of key functional components in microfluidic chips is always limited by the existing processing methods. The microfluidic chip is difficult to be three-dimensional (3D) and integrated.

Simple and Low-Cost Oil/Water Separation Based on the Underwater Superoleophobicity of the Existing Materials in Our Life or Nature.

The achievement of high-efficiency oil/water separation has huge implications for protecting environment and reducing economic losses, but there is still a great challenge. Currently, most artificial oil/water separating materials are fabricated through complex preparation process, resulting in the very high cost of separation. In this paper, we present a simple and low-cost method to achieve oil/water separation by using the underwater superoleophobic materials that already exist in our life or nature.

Femtosecond laser preparing patternable liquid-metal-repellent surface for flexible electronics.

Hypothesis: Controlling the wetting behaviour of gallium-based liquid metal is highly desired for soft electronics applications. Currently, achieving durable and patternable liquid-metal-repellent surfaces by a simple and flexible method is challenging. The femtosecond laser has a remarkable ability to modify the morphology and wettability of a solid surface.

Tuning a surface super-repellent to liquid metal by a femtosecond laser.

Eutectic gallium-indium (EGaIn) liquid metal (LM) attracts increasing interest because of its broad applications in flexible circuits and soft devices. However, LM can easily adhere to a solid substrate due to the existence of a high-adhesive oxide outside layer, which greatly limits the real application of LM materials. Current methods to reduce the LM adhesion are mostly based on chemical treatment rather than surface microstructure, which are not suitable for most practical applications.

Underwater superoleophobic and anti-oil microlens array prepared by combing femtosecond laser wet etching and direct writing techniques.

As an important micro-optical device, microlens array (MLA) also has broad applications in aqueous environment apart from atmosphere, such as bioscience research, ocean exploration, and microfluidic systems. However, the surface of the normal MLA is easily polluted by oil contaminations when the MLA is practically applied in a water medium, leading to the loss of its optical imaging ability. Herein, we fabricated a functional MLA with underwater anti-oil and self-cleaning abilities by combining the femtosecond laser wet etching (FLWE) and the femtosecond laser direct writing (FLDW) techniques.

Femtosecond-Laser-Produced Underwater "Superpolymphobic" Nanorippled Surfaces: Repelling Liquid Polymers in Water for Applications of Controlling Polymer Shape and Adhesion.

A femtosecond (fs)-laser-processed surface that repels liquid polymer in water is reported in this paper. We define this phenomenon as the "superpolymphobicity". Three-level microstructures (including microgrooves, micromountains/microholes between the microgrooves, and nanoripples on the whole surface) were directly created on the stainless steel surface via fs laser processing.

Femtosecond Laser-Structured Underwater "Superpolymphobic" Surfaces.

In this work, the surfaces that repel liquid polydimethylsiloxane (PDMS) droplets in water were created by femtosecond laser treatment. We define this superwetting phenomenon as underwater "superpolymphobicity". The resultant underwater superpolymphobic silicon surface shows a contact angle of 159 ± 1° and a sliding angle of 1.

A review of femtosecond laser-structured superhydrophobic or underwater superoleophobic porous surfaces/materials for efficient oil/water separation.

Oil/water separation (OWS) technology has become an increasingly crucial tool to protect the environment and reduce the economic losses caused by the discharge of oily wastewater and oil spills. Recently, porous materials with superwettability have been applied in effective OWS and have achieved tremendous success. Herein, we review recent advancements of OWS utilizing femtosecond (fs) laser-structured superhydrophobic or underwater superoleophobic porous materials.

A femtosecond laser-induced superhygrophobic surface: beyond superhydrophobicity and repelling various complex liquids.

Surfaces that can strongly repel various complex liquids, not just pure water, are highly desirable and the fabrication of such surfaces still remains a huge challenge because the liquids one wants to repel usually have a complex chemical composition, viscosity, and concentration. Here, a superhygrophobic surface microstructure was created on a polytetrafluoroethylene (PTFE) surface by femtosecond laser treatment. The laser-ablated surface was composed of a micro/nanoscale hierarchical structure and micropores with a certain degree of re-entrant curvature.