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The fabrication of a stable, anti-wetting surface is a very challenging issue in surface chemistry. In general, superhydrophobicity highly depends on the surface structure. Moreover, mechanical deformation of the surface structure can produce dramatic changes in the surface wetting state, and in some cases, may even result in a complete loss of the surface's unique wettability. However, the study of stable surfaces under mechanical deformation conditions has been limited to flexible surfaces or small strain. Here, a mechanically stable superhydrophobic membrane is presented, which possesses high stretchability and gas breathability. The membrane, which consists of an elastic polyurethane fibrous matrix coated with polyaniline hairy nanostructures and polytetrafluoroethylene, exhibites excellent superhydrophobic properties under ≥300% strain. The breathability and wettability of the membrane is examined by examining various static and dynamic wetting parameters. The robust membrane maintaines its anti-wettability (water contact angle ≈160°, hysteresis ≈10°) for 1000 stretching cycles. It is also determined that the stretchable and superhydrophobic surface suppresses the fragmentation and rebound of impact droplets, compared with rigid superhydrophobic surfaces. Finally, underwater gas sensing is demonstrated as a novel application. [ABSTRACT FROM AUTHOR]

A schemetic of the mechanically stable superhydrophobic membrane, with high stretchability and gas breathability, created by G. Lim and co‐workers on page 5577. The scanning electron microscopy image in the upper left shows as‐prepared nanostructured fibers. The image in the lower right corner presents nanocracked fibers. The 3D schematic in the center shows the hierarchical structure, which consists of an elastic polyurethane fibrous matrix coated with polyaniline hairy nanostructures and polytetrafluoroethylene. The membrane exhibits excellent superhydrophobic properties under ≥300% strain. [ABSTRACT FROM AUTHOR]

To date, several off-the-shelf products such as artificial blood vessel grafts have been reported and clinically tested for small diameter vessel (SDV) replacement. However, conventional artificial blood vessel grafts lack endothelium and, thus, are not ideal for SDV transplantation as they can cause thrombosis. In addition, a successful artificial blood vessel graft for SDV must have sufficient mechanical properties to withstand various external stresses. Here, we developed a spontaneous cellular assembly SDV (S-SDV) that develops without additional intervention. By improving the dragging 3D printing technique, SDV constructs with free-form, multilayers and controllable pore size can be fabricated at once. Then, The S-SDV filled in the natural polymer bioink containing human umbilical vein endothelial cells (HUVECs) and human aorta smooth muscle cells (HAoSMCs). The endothelium can be induced by migration and self-assembly of endothelial cells through pores of the SDV construct. The antiplatelet adhesion of the formed endothelium on the luminal surface was also confirmed. In addition, this S-SDV had sufficient mechanical properties (burst pressure, suture retention, leakage test) for transplantation. We believe that the S-SDV could address the challenges of conventional SDVs: notably, endothelial formation and mechanical properties. In particular, the S-SDV can be designed simply as a free-form structure with a desired pore size. Since endothelial formation through the pore is easy even in free-form constructs, it is expected to be useful for endothelial formation in vascular structures with branch or curve shapes, and in other tubular tissues such as the esophagus., Competing Interests: Hun-Jin Jeong, Hyoryung Nam, Young-Sam Cho, Jinah Jang, Seung-Jae Lee have competing interest since they are the inventor of a patent on the Artificial esophageal scaffold with multi-layer tubular using 3D bioprinting and fabricating device and fabricating method thereof (Korea Patent no. 10–2274151). Hun-Jin Jeong, Young-Sam Cho, Jinah Jang, Seung-Jae Lee have competing interest since they are the inventor of a patent on the Artificial vascular scaffold with multi-layer tubular using 3D bioprinting and fabricating device and fabricating method thereof (Korea Patent no. 10–2306282). Hun-Jin Jeong, Young-Sam Cho, Seung-Jae Lee have competing interest since they are the inventor of a patent on the Scaffold and fabrication method by dragging technique (Korea Patent no. 10–2026635). The remaining 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., (© 2023 The Authors.)