다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Through 3.7 billion years of evolution and natural selection, plants and animals in nature have ingeniously fulfilled a broad range of fascinating functions to achieve optimized performance in responding and adapting to changes in the process of interacting with complex natural environments. It is clear that the hierarchically organized micro/nanostructures of the surfaces of living organisms decisively manage fascinating and amazing functions, regardless of the chemical components of their building blocks. This conclusion now allows us to elucidate the underlying mechanisms whereby these hierarchical structures have a great impact on the properties of the bulk material. In this review, we mainly focus on advances over the last three years in bioinspired multiscale functional materials with specific wettability. Starting from selected naturally occurring surfaces, manmade bioinspired surfaces with specific wettability are introduced, with an emphasis on the cooperation between structural characteristics and macroscopic properties, including lotus leaf-inspired superhydrophobic surfaces, fish scale-inspired superhydrophilic/underwater superoleophobic surfaces, springtail-inspired superoleophobic surfaces, and Nepenthes (pitcher plant)-inspired slippery liquid-infused porous surfaces (SLIPSs), as well as other multifunctional surfaces that combine specific wettability with mechanical properties, optical properties and the unidirectional transport of liquid droplets. Afterwards, various top-down and bottom-up fabrication techniques are presented, as well as emerging cutting-edge applications. Finally, our personal perspectives and conclusions with regard to the transfer of micro- and nanostructures to engineered materials are provided.

Recent advances of bioinspired functional materials with specific wettability: from nature and beyond nature

Liquid-infused surfaces (or lubricant-infused surfaces) (LIS) are a new class of functional materials introduced in 2011. Their exceptional properties have earned them a place at the forefront of many fields including anti-biofouling, anti-icing, anti-corrosion, drag reduction, droplet manipulation and drop-wise condensation. Integral to their success is the infused lubricant layer which affords them their properties. In this review, we examine the current state of the literature relating to the lubricant layer. We consider the lubricant through all stages in the surface's lifecycle from design, to use, all the way through to depletion and eventual failure. First, we examine trends in lubricant choice and how to choose a lubricant, including environmental and medical considerations. We then look at the different methods used to infuse lubricant into surfaces and how lubricant depletes from the surface. We then report direct and indirect methods to characterise the thickness and distribution of the lubricant layer. Finally, we examine how droplets interact with LIS and the unique properties afforded by the lubricant before providing an outlook into where research centred on understanding the lubricant layer is heading in the new decade.

Life and death of liquid-infused surfaces: a review on the choice, analysis and fate of the infused liquid layer.

A hitherto unknown mechanism for wetting transition is reported. When a pendant drop settles upon deposition, there is a virtual "collision" where its center of gravity undergoes rapid deceleration. This induces a high water hammer-type pressure that causes wetting transition. A new phase diagram shows that both large and small droplets can transition to wetted states due to the new deceleration driven and the previously known Laplace mechanisms, respectively. It is explained how the attainment of a nonwetted Cassie-Baxter state is more restrictive than previously known.

Rapid Deceleration-Driven Wetting Transition during Pendant Drop Deposition on Superhydrophobic Surfaces

External Stimuli Responsive Liquid‐Infused Surfaces Switching between Slippery and Nonslippery States: Fabrications and Applications

Namib Desert beetles harvest water from harsh environments by using their hydrophilic-hydrophobic dorsal surfaces. Generally, Cassie-state superhydrophobic materials are chosen as substrates to prepare bioinspired (super)hydrophilic/(super)hydrophobic patterned surfaces. However, due to the low adhesion and strong repellency, aqueous solution cannot be directly set on Cassie superhydrophobic materials until the dropping volume is larger than 6.5 μL. Therefore, arranging a (super)hydrophilic substance on Cassie superhydrophobic substrates to construct (super)hydrophilic/superhydrophobic patterned surfaces still remains a challenge. In this work, by prewetting with dichloromethane (DCM), the mussel-inspired hydrophilic and bio-adhesive dopamine solution (DA) could be dripped onto a Cassie superhydrophobic Cu surface with an ultralow volume of 0.1 μL, whereby low surface tension DCM would "cloak" the high surface tension DA. Along with DCM volatility, DA was adhered on the Cassie superhydrophobic surface and would then self-polymerize into hydrophilic polydopamine domains, thus hydrophilic/superhydrophobic patterned surfaces with efficient water collection could be successfully developed inspired by Namib Desert beetles and mussels. The bioinspired materials show the potential for real-world industrialization in a large scale, which is of great significance for providing living security for those living in areas with no access to fresh water.

Prewetting dichloromethane induced aqueous solution adhered on Cassie superhydrophobic substrates to fabricate efficient fog-harvesting materials inspired by Namib Desert beetles and mussels.

Precise control of a biological droplet's adhesive force on a liquid-repellent surface for smart antifouling systems is critical and fundamental to scientific research and industrial applications. Although slippery surfaces with stimuli-responsive wetting behaviors have been reported, challenge still remains in designing responsive biological droplets to achieve controllable adhesion and antifouling property. Here, we developed a thermoresponsive biological droplet adhesion system to precisely control its adhesion on the lubricant-infused slippery surface. Single-stranded DNA (ssDNA) in the biological droplet displays molecular configuration reversible deformation under external thermal stimuli. This property ascribes to the changing amount of exposed hydrophobic moieties of ssDNA, which strongly affects the interfacial hydrophobic interaction with the lubricant. This work may improve the understanding of the principles underlying liquid-lubricant interfacial adhesion, open up opportunities for a new class of antifouling systems, and provide a promising system for controllable manipulation of liquids' motion in biochips and microreactor devices.

Temperature-Driven Precise Control of Biological Droplet's Adhesion on a Slippery Surface.

In this work, a superhydrophobic material was successfully prepared with a water contact angle of about 155.5° and a rolling-off angle of about 6.8°, which showed superior UV resistance (365 nm, 5.0 ± 0.6 mW cm-2) for an illumination period of 30 h. The degradation of organic dyes, such as Nile red, methyl blue and orange, could be also achieved with our prepared surface. Anti-UV water-repellency was combined with photocatalysis to realize a self-cleaning surface for both dirt removal and organic degradation. Moreover, the reversible changes with superhydrophobicity and superhydrophilicity were induced by the self-healing property on such a surface, contributing to heavy and light oils/water separation. Because of ultra-long UV-resistance, photocatalysis, self-cleaning, self-healing and oil/water separation functions, our reported surface has potential for application in a variety of fields.

Hai Zhu

Papers

External Stimuli Responsive Liquid‐Infused Surfaces Switching between Slippery and Nonslippery States: Fabrications and Applications

Prewetting dichloromethane induced aqueous solution adhered on Cassie superhydrophobic substrates to fabricate efficient fog-harvesting materials inspired by Namib Desert beetles and mussels.

Temperature-Driven Precise Control of Biological Droplet's Adhesion on a Slippery Surface.

An anti-UV superhydrophobic material with photocatalysis, self-cleaning, self-healing and oil/water separation functions

Beetle-inspired wettable materials: from fabrications to applications