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Microfluidics and bioinspired superwetting materials, as two crucial branches of scientific research, are entering their golden age of development. As an emerging interdisciplinary subject of these two fields, bioinspired superwetting open microfluidics is triggering technological revolutions in many disciplines, including rapid medical diagnosis, biochemical analysis, liquid manipulation, 3D printing, etc. However, this new research area has yet to attract extensive attention. So, a timely review is necessary to organize the development process, summarize current achievements, and discuss the challenges or chances for the ongoing scientific trend. In this review, the evolution from closed to open microfluidics is combed first. Then, three typical bioinspired superwetting systems are introduced emphatically. Based on this, the bioinspired superwetting open microfluidics is divided into different categories according to the bionic objects as the focus of this study. Taking natural phenomena as the entry point, the research from the underlying mechanism to the application is systematically discussed and summarized. Several emerging applications are also mentioned. Finally, some views on major problems, existing challenges, and developing trends are briefly put forward in this field to guide future research. [ABSTRACT FROM AUTHOR]

Microfluidics has experienced rapid progress in additive manufacturing and microfluidic soft robots. The design of microfluidics is already moving into a more intelligent, integrated, and detachable direction. However, the pipeline resistance needs more external energy input to achieve high flow speed. Guided transport of liquid in the open‐air‐space microfluidics will be an effective solution. Inspired by the water shuttle on the pitcher plant tendril, herein, an open‐air microfluidic transport device is designed that consists of a superhydrophilic microwick with multi‐microgrooves by stereolithography. The liquid film confined in microgrooves can promote rapid fluid shuttle on the wet surface to enhance transport rate and inhibit the Rayleigh‐Plateau instability from forming larger dripping drops. The dripping volume and threshold Capillary number are optimized for effective liquid transport and drainage. State‐of‐the‐art microwick liquid shuttle technologies can guide liquid continuously in a prescribed direction or into multiple directions with 98% transport efficiency (the ratio of liquid collection volume and liquid injection volume) for water and 97% for ethanol in the closed‐open‐closed space. The proposed mechanism has the potential to streamline microfluidic applications—and, therefore, accelerate relevant liquid delivery development and ultimately their applications in microfluidic chip and additive manufacturing. [ABSTRACT FROM AUTHOR]

Highly sensitive flexible pressure sensors are extensively investigated for various applications, such as electronic skin, human physiological monitoring, and artificial intelligence. However, traditional fabrication technologies are hard to realize the large‐area and mass production of wearable sensing devices. Current trend of miniaturization, systematization, and multifunction has raised the problems of total energy consumption, frequent charging, and reduced usage time. These issues have hindered the progress of wearable sensing electronics. In the light of nanomaterial design, mass production, and facile manufacturing, electrospun piezoelectric pressure sensors offer the best properties of self‐powering, breathability, stretchability, and flexibility, providing ideal interfacing platforms for smart wearables. Tremendous advances have been achieved recently in the high sensitivity, piezoelectric output, composite optimization, and nano‐/microstructure design of nonwoven nanofiber membranes. Nevertheless, how to fulfill real textile‐level integration in consideration of biocompatibility, integration, wearability, geometrical design, multifunction, and systematization remains a big challenge. Therefore, recent progress of piezoelectric pressure sensors from electrospun nanofibers to their fabrics is comprehensively summarized. Plentiful strategies, structure designs, and underlying mechanisms that boost the piezoelectric properties are discussed. Lastly, the challenges and possible solutions for the future electrospinning‐based pressure sensing systems are proposed. [ABSTRACT FROM AUTHOR]

In the past few years, bioinspired eco-friendly superhydrophobic materials (EFSMs) have made great breakthroughs, especially in the fields of environment, energy and biology, which have made remarkable contributions to the sustainable development of the natural environment. However, some potential challenges still exist, which urgently need to be systematically summarized to guide the future development of this field. Herein, in this review, initially, we discuss the five typical superhydrophobic models, namely, the Wenzel, Cassie, Wenzel–Cassie, "lotus", and "gecko" models. Then, the existence of superhydrophobic creatures in nature and artificial EFSMs are summarized. Then, we focus on the applications of EFSMs in the fields of environment (self-cleaning, wastewater purification, and membrane distillation), energy (solar evaporation, heat accumulation, and batteries), and biology (biosensors, biomedicine, antibacterial, and food packaging). Finally, the challenges and developments of eco-friendly superhydrophobic materials are highlighted. [ABSTRACT FROM AUTHOR]

DeepLab v3+ neural network shows excellent performance in semantic segmentation. In this paper, we proposed a segmentation framework based on DeepLab v3+ neural network and applied it to the problem of hyperspectral imagery classification (HSIC). The dimensionality reduction of the hyperspectral image is performed using principal component analysis (PCA). DeepLab v3+ is used to extract spatial features, and those are fused with spectral features. A support vector machine (SVM) classifier is used for fitting and classification. Experimental results show that the framework proposed in this paper outperforms most traditional machine learning algorithms and deep-learning algorithms in hyperspectral imagery classification tasks. [ABSTRACT FROM AUTHOR]

Janus superhydrophilic/hydrophobic macroporous nickel foam for directional water transport has been demonstrated via a simple floating strategy. Water can transport from hydrophobic to superhydrophilic layer through Janus nickel foam, but cannot transfer from superhydrophilic to hydrophobic layer. This “3D water diode” Janus nickel foam shows extremely high transport rate and outstanding stability. After damaged by abrasion, its directional water transport property retains well. [ABSTRACT FROM AUTHOR]

Superhydrophobic (SHP) coatings inspired by lotus have great application prospect for our daily life. Regrettably, three formidable challenges, namely, complex fabrication, weak mechanical stability and large-scale fabrication, have already existed for a long time in this research field. Here, a robust micro-nanoscale P25 (Nano TiO 2 )/MgO/epoxy resin (ER) SHP coating has been fabricated via facile one-pot route, which can be applied to arbitrary substrates through multiples methods. P25/MgO/ER SHP coating not only displays excellent mechanical stability but also shows unique repairable ability to recover its superhydrophobicity under various damages by extreme environment such as low temperature, strong acid or alkali and this repairable process can be repeated for many times. P25/MgO/ER SHP coating also is easy to large-scale fabrication with very low cost. [ABSTRACT FROM AUTHOR]

Sand, an abundant natural resource, is the cause behind the harsh environmental conditions of the desert, such as water shortages and sand storms. Because of the strong hydrophilicity of sand itself, water can be quickly absorbed by sand, which greatly impedes desert greening, water storage and transportation projects. In contrast to this conventional understanding of sand (i.e., superhydrophilicity), we propose the design of “superhydrophobic sand”, aimed to address issues associated with the desert environment and sand resource utilization. In our experiments, three kinds of hydrophobic sands with different surface structures and wettability properties were successfully prepared by cladding nonmetal (SiO2) and metal (Ag and Cu) inorganic materials on sand grain surfaces and then modifying them with low-surface-energy chemicals. Combining superhydrophobicity with desert sand, superhydrophobic sand (PFDS-sand@SiO2) is shown to have excellent water repellency, allowing water to stably remain and flow on such a sand surface without any wetting or permeation. Furthermore, the superhydrophobic sand demonstrates a great water-holding capacity, such that a sand layer with a thickness of 2 cm can sustain a water column height of 35 cm. Very significantly, PFDS-sand@SiO2 exhibits extremely high thermal stability up to 400 °C when used for water storage. This result is unprecedented and sufficient for facing the high-temperature conditions of the desert environment and some others. In addition to reliable water storage, such superhydrophobic sand also demonstrates a great anti-flow-dragging effect during water transportation, whereby a water droplet can smoothly and quickly roll down a simulated sand channel (13 cm length) within 0.3 s (∼0.45 m s−1). All of these manifestations imply the significant potential of such “superhydrophobic sand” in its application to desert water storage and transportation. [ABSTRACT FROM AUTHOR]

The development of fabrication techniques for superhydrophobic coatings is rapidly maturing, yet the problem of low mechanical durability still persists. To address this problem, we introduce a robust micro-nanoscale flowerlike ZnO/epoxy resin superhydrophobic coating possessing a rapid healing ability after ultra-abrasion. The coating was fabricated by a simple immersion method, and it presented a water contact angle above 150° and a sliding angle of less than 2°. A simple abrasion test (2400 linear abrasion times at a pressure of 5 kPa) was conducted to show that the coating could maintain superhydrophobicity, even after undergoing thirty abrasion times. Meanwhile, it could be easily repaired within one minute of the coating losing superhydrophobicity under ultra-abrasion. The abrasion only impacted the thickness of the rough structure (grown on the coating surface by immersion) and had almost no effect on the original thickness of the coating itself. This coating had an extremely long service life and may be useful for a wide range of applications. [ABSTRACT FROM AUTHOR]

Inspired by mussels we designed a novel green superhydrophobic gel nanocoating with good transparency and stability through a facile copolymerization reaction at room temperature and a subsequent trimethyl silyl modified process, which is applicable to various substrates via a simple spray process without requiring toxic substances. Importantly, this well-designed nanocoating has rapid self-healing superhydrophobicity induced by usual organic solvents to face complicated work conditions, which satisfies the need of daily life and can be applied in industry as well. [ABSTRACT FROM AUTHOR]

Review: 67 refs. [ABSTRACT FROM AUTHOR]

Although the development of superhydrophobic coatings is rapidly maturing, issues related to their low mechanical durability persist. In this context, the effect of substrate roughness on the service life of superhydrophobic coatings was studied. In this study, superhydrophobic coatings were fabricated on sandpapers of different roughness and reciprocating wear tests were conducted. The wear-resistance number of the superhydrophobic coating, defined as the maximum number of friction cycles after which the superhydrophobic surface started to lose its superhydrophobicity, increased from 50 to 24,000 with an increase in the substrate roughness from 2000 CW to 240 CW (CW is defined as the number of particles arranged in an inch), while it decreased from 24,000 to 17,000 with a further increase in the substrate roughness from 240 CW to 60 CW. Observations of the surface structure and wear analyses indicated that the superhydrophobic material infiltrated the spaces between the sand grains, and the rough peaks could consequently protect the superhydrophobic material during the wear tests. However, this protection weakens when the substrate roughness increases or decreases beyond certain values. Furthermore, these phenomena and results were also verified by applying the superhydrophobic coatings to different types of common substrates. [ABSTRACT FROM AUTHOR]

Bioinspired superwetting oil-water separation strategies have received significant attention for their potential in addressing global water scarcity and aquatic pollution challenges. Over the past two decades, the field has rapidly developed, reaching a pivotal phase of innovation in the oil-water separation process. However, many groundbreaking studies have not received extensive scientific recognition. In this review, we systematically examine the application of bioinspired superwetting materials for complex multiscale oil-water separation. We discuss the development of 2D membrane filtration and 3D sponge adsorption materials in confined spaces, summarizing the core separation mechanisms, key research findings, and the evolutionary logic of these materials. Additionally, we highlight emerging open-space separation strategies, emphasizing several novel dynamic separation devices of significant importance. We evaluate and compare the design concepts, separation principles, materials used, comprehensive performance, and existing challenges of these diverse strategies. Finally, we summarize these advantages, critical bottlenecks, and prospects of this field and propose potential solutions for real oil-water separation processes from a general perspective.

Conventional microscopic spectral imaging suffers from extended scanning times across wavelength or spatial dimension. To improve capabilities of dynamic microscopic spectral imaging, we developed a snapshot computed tomographic microscopic imaging spectrometer (CTMIS) based on the zeroth and first orders dispersive diffraction of a two-dimensional grating. Utilizing the CTMIS-UNET reconstruction algorithm, we can reconstruct a spectral cube (541x541x26) for each frame of micro spectral imaging video. Experimental results demonstrate a sub-4 μm spatial resolution achievable through a 20x objective lens and a spectral resolution better than 10 nm among 450-700 nm, while maintaining spectral cosine similarities exceeding 0.9989 when comparing reconstructed spectra with ground truth data. Spectral imaging videos of four species of algae and mixed algae were captured under 10 ms exposure time using the CTMIS system. Leveraging the self-developed UNET-SI26 algae recognition network, precise identification and tracking of four types of algae and poisonous microcysts aeruginosa in mixed algae were conducted. The pixel-level recognition accuracy exceeds 95 %, while the accuracy for counting the numbers of different types of cells surpasses 85 %, offering an efficient and accurate spectral imaging method for real-time monitoring and early warning of harmful algae at the cellular level., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Developing an intelligent wearable system is of great significance to human health management. An ideal health-monitoring patch should possess key characteristics such as high air permeability, moisture-wicking function, high sensitivity, and a comfortable user experience. However, such a patch that encompasses all these functions is rarely reported. Herein, an intelligent bionic skin patch for health management is developed by integrating bionic structures, nano-welding technology, flexible circuit design, multifunctional sensing functions, and big data analysis using advanced electrospinning technology. By controlling the preparation of nanofibers and constructing bionic secondary structures, the resulting nanofiber membrane closely resembles human skin, exhibiting excellent air/moisture permeability, and one-side sweat-wicking properties. Additionally, the bionic patch is endowed with a high-precision signal acquisition capabilities for sweat metabolites, including glucose, lactic acid, and pH; skin temperature, skin impedance, and electromyographic signals can be precisely measured through the in situ sensing electrodes and flexible circuit design. The achieved intelligent bionic skin patch holds great potential for applications in health management systems and rehabilitation engineering management. The design of the smart bionic patch not only provides high practical value for health management but also has great theoretical value for the development of the new generation of wearable electronic devices., (© 2023 Wiley‐VCH GmbH.)

Maintaining a reasonably stable body temperature is vital for a variety of human activities in an energy-conservation strategy. However, it is well-known that metal-like materials, utilized as radiative reflectors, severely restrict wearability properties, thus posing a tremendous obstacle in personal thermal management (PTM) systems. Herein, we designed a supramolecular-enhanced membrane (SupraEM) acting as a mid-infrared (MIR) reflector to solve the conundrum of warmth-wearability performance. Benefiting from the low-emissivity of decorating titanium carbide (MXene) and the formation of supramolecular interactions, the prototyped polyvinylidene difluoride&Polyurethane/MXene (PVDF&PU/MXene) SupraEM demonstrated a low-emissivity of 0.246 and reinforced mechanical performance, resulting in an evenly higher temperature retention of 8 °C in comparison to the pristine hybrid membrane counterpart, and compared with a commercial textile that is three times thicker, it also exhibited higher temperature retention of 6.2 °C. This work demonstrates the wearability of decorated MXene without sacrificing its temperature retention, overcoming a major bottleneck that has plagued MXene as a thermoregulatory material for PTM systems.

Developments in bioinspired superwetting materials have triggered technological revolutions in many disciplines. One representative area is liquid directional transport dominated by interface properties, which has experienced rapid progress recently. To improve the controllability, scientists try to use the external field, such as light, electricity, thermal, and so on, to assist or achieve controllable smart, responsive liquid directional transport. However, there are still some intractable problems and challenges behind prosperity. Here, we summarize the relevant basic theory of surface wettability and the processes of the development of bioinspired superwetting materials. We discuss the different essential mechanisms of liquid directional transport. Furthermore, smart external field-controlled fluid directional transport is the primary focus of this feature article. We briefly put forward our views on some outstanding problems, existing challenges, and trends in this field.

Effective droplet emission is of fundamental importance for practical application, such as agricultural sprays to painting, atomization, emulsification, and catalytic action. Highly viscous liquids are commonly used, such as printing inks, which hinder the ejection at the nozzle. A big challenge faced by people is how to obtain stable and controllable liquid droplets in a wide range of viscosities. Inspired by the rotation shaking of droplets on fiber clusters and the rotary spraying disk technique, here, we demonstrate uniform microdroplet (1-2000 mPa·s) generation in a tip-guided way that replaces the commonly confined nozzle by a double-layer spinning "sandwich" multitip disk (SSMD). A surface energy gradient induced by the margin structure of the alternating gas wedge and solid tip guides liquid to move along the solid tip, which is ejected at the end of the tip, forming a ring of droplet clusters. SSMD improves the effective droplet-jet process to 7/10 of the whole drainage process and enhances the efficiency with a production drop volume of ∼3.19 × 10 7 μL/h and production droplet numbers of ∼3.3 × 10 4 per second. Droplets can be fine-tuned between 0.1 and 1.0 mm via the tip structure, liquid property, and spinning angular velocity with a narrow size distribution. This facile tip-guided design could inspire the possibility of energy-efficient droplet production techniques in various fluid applications, such as spraying and printing. It may further improve other fluid systems that serve as a crucial component for high-speed droplet manipulation, liquid transport, and water vapor capturing.