Self‐healing hydrophobic light‐to‐heat conversion membranes for interfacial solar heating are fabricated by deposition of light‐to‐heat conversion material of polypyrrole onto a porous stainless‐steel mesh, followed by hydrophobic fluoroalkylsilane modification. The mesh‐based membranes spontaneously stay at the water–air interface, collect and convert solar light into heat, and locally heat only the water surface for enhanced evaporation.

Direct micropatterning of superhydrophilicity on superhydrophobic surfaces was achieved by inkjet printing a mussel-inspired ink of dopamine solution onto the superhydrophobic surface, followed by the formation of polydopamine. The micropatterned superhydrophobic surfaces exhibited an enhanced fog-harvesting efficiency.

We report a simple methodology to fabricate PDMS multi-layer microfluidic chips. A PDMS slab was surface-treated by trichloro (1H,1H,2H,2H-perfluorooctyl) silane, and acts as a reusable transferring layer. Uniformity of the thickness of the patterned PDMS layer and the well-alignment could be achieved due to the transparency and proper flexibility of this transferring layer. Surface treatment results are confirmed by XPS and contact angle testing, while bonding forces between different layers were measured for better understanding of the transferring process. We have also designed and fabricated a few simple types of 3D PDMS chip, especially one consisting of 6 thin layers (each with thickness of 50 mum), to demonstrate the potential utilization of this technique. 3D fluorescence images were taken by a confocal microscope to illustrate the spatial characters of essential parts. This fabrication method is confirmed to be fast, simple, repeatable, low cost and possible to be mechanized for mass production.

COVID-19 is an acute respiratory disease caused by SARS-CoV-2, which has high transmissibility. People infected with SARS-CoV-2 can develop symptoms including cough, fever, pneumonia and other complications, which in severe...

Fog water collection represents a meaningful effort in the places where regular water sources, including surface water and ground water, are scarce. Inspired by the amazing fog water collection capability of Stenocara beetles in the Namib Desert and based on the recent work in biomimetic water collection, this work reported a facile, easy-to-operate, and low-cost method for the fabrication of hydrophilic-superhydrophobic patterned hybrid surface toward highly efficient fog water collection. The essence of the method is incorporating a (super)hydrophobically modified metal-based gauze onto the surface of a hydrophilic polystyrene (PS) flat sheet by a simple lab oven-based thermal pressing procedure. The produced hybrid patterned surfaces consisted of PS patches sitting within the holes of the metal gauzes. The method allows for an easy control over the pattern dimension (e.g., patch size) by varying gauze mesh size and thermal pressing temperature, which is then translated to an easy optimization of the ultimate fog water collection efficiency. Given the low-cost and wide availability of both PS and metal gauze, this method has a great potential for scaling-up. The results showed that the hydrophilic-superhydrophobic patterned hybrid surfaces with a similar pattern size to Stenocara beetles's back pattern produced significantly higher fog collection efficiency than the uniformly (super)hydrophilic or (super)hydrophobic surfaces. This work contributes to general effort in fabricating wettability patterned surfaces and to atmospheric water collection for direct portal use.

a b s t r a c tIn this study, we established a simple method for evaluating the PCR compatibility of various common materials employed when fabricating microfluidic chips, including silicon, several kinds of silicon oxide, glasses, plastics, wax, and adhesives. Two-temperature PCR was performed with these materials to determine their PCR-inhibitory effect. In most cases, adding bovine serum albumin effectively improved the reaction yield. We also studied the individual PCR components from the standpoint of adsorption. Most of the materials did not inhibit the DNA, although they noticeably interacted with the polymerase. We provide a simple method of performing PCR-compatibility testing of materials using inexpensive instrumentation that is common in molecular biology laboratories. Furthermore, our method is direct, being performed under actual PCR conditions with high temperature. Our results provide an overview of materials that are PCR-friendly for fabricating microfluidic devices. The PCR reaction, without any additives, performed best with pyrex glass, and it performed worst with PMMA or acrylic glue materials.

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Recently, wearable pressure sensors have attracted considerable interest in various fields such as healthcare monitoring, intelligent robots, etc. Although artificial structures or conductive materials have been well developed, the trade-off between sensitivity and linearity of pressure sensors is yet to be fully resolved by a traditional approach. Herein, from theoretical analysis to experimental design, we present the novel CPDMS/AgNWs double conductive layer (DCL) to synergistically optimize the sensitivity and linearity of piezoresistive pressure sensors. The facilely fabricated solid microdome array (SDA) is first employed as the elastomer to clarify the unrevealed working mechanism of DCL. Attributed to the synergistic effect of DCL, the DCL/SDA based sensor exhibits ultrahigh sensitivity (up to 3788.29 kPa–1) in an obviously broadened linearity range (0–6 kPa). We also demonstrated that the synergistic effect of DCL can be regulated with use of porous microdome array (PDA) to further optimize the sensing property. The linearity range can be improved up to 70 kPa while preserving the high sensitivity of 924.37 kPa–1 based on the interlocked PDA structure (IPDA), which is rarely reported in previous studies. The optimized sensitivity and linearity allow the competitive DCL/IPDA based sensor as a reliable platform to monitor kinds of physiological signals covering from low pressures (e.g., artery pulses), medium pressures (e.g., muscle expansions), to high pressures (e.g., body motions). We believe that the methodology along with the robust sensor can be of great potential for reliable healthcare monitoring and wearable electronic applications in the future.