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Extrusion-based 3D printers have been adopted in pursuit of engineering functional tissues through 3D bioprinting. However, we are still a long way from the promise of fabricating constructs approaching the complexity and function of native tissues. A major challenge is presented by the competing requirements of biomimicry and manufacturability. This opinion article discusses 3D printing in suspension baths as a novel strategy capable of disrupting the current bioprinting landscape. Suspension baths provide a semisolid medium to print into, voiding many of the inherent flaws of printing onto a flat surface in air. We review the state-of-the-art of this approach and extrapolate toward future possibilities that this technology might bring, including the fabrication of vascularized tissue constructs. 3D printing in suspension media unlocks the full potential of extrusion-based 3D printers by providing a strategy for fabricating non–self-supporting structures from water-rich, low-viscosity bioinks.Biomimetic structures representative of native vascular channels have been printed in suspension media, demonstrating that both omnidirectional printing and printing in discrete arbitrary locations are possible with this printing strategy.Retention of a suspension medium following printing of embedded constructs is achievable through crosslinking. Suspension media are therefore able to double as a 3D cell culture substrate in which printed features such as vessels or cell populations can help with maturing of the engineered tissue.

Liquid metal is being regarded as a promising material for soft electronics owing to its distinct combination of high electrical conductivity comparable to that of metals and exceptional deformability derived from its liquid state. However, the applicability of liquid metal is still limited due to the difficulty in simultaneously achieving its mechanical stability and initial conductivity. Furthermore, reliable and rapid patterning of stable liquid metal directly on various soft substrates at high-resolution remains a formidable challenge. In this work, meniscus-guided printing of ink containing polyelectrolyte-attached liquid metal microgranular-particle in an aqueous solvent to generate semi-solid-state liquid metal is presented. Liquid metal microgranular-particle printed in the evaporative regime is mechanically stable, initially conductive, and patternable down to 50 μm on various substrates. Demonstrations of the ultrastretchable (~500% strain) electrical circuit, customized e-skin, and zero-waste ECG sensor validate the simplicity, versatility, and reliability of this manufacturing strategy, enabling broad utility in the development of advanced soft electronics. In this article, meniscus-guided printing of polyelectrolyte-attached liquid metal particles to simultaneously achieve mechanical stability and initial electrical conductivity at high resolution is introduced.

One of the main goals of applied morphology is to make the teaching of normal anatomy visual. Natural preparations of organs and body parts of an animal should be demonstrative enough and retain their shape and appearance for a long time. Compared to others, the method that we have developed for the manufacture of anatomical preparations has significant advantages, and in such a quality that makes it possible to study the object not only visually, but also manually. At the same time, soft anatomical preparations made in this way are biologically and toxicically safe. Preservation of organs and tissues of animal corpses is a necessary part of the work of anatomists and pathologists with the obligatory use of these preparations in the educational process, including for independent work of students. The method that we have optimized for the manufacture of wet pathological specimens, which have high visibility, close to the natural color and shape of eviscerated organs and tissues, while being stored longer.

Perovskite solar cells promise to be part of the future portfolio of photovoltaic technologies, but their instability is slow down their commercialization. Major stability assessments have been recently achieved but reliable accelerated ageing tests on beyond small-area cells are still poor. Here, we report an industrial encapsulation process based on the lamination of highly viscoelastic semi-solid/highly viscous liquid adhesive atop the perovskite solar cells and modules. Our encapsulant reduces the thermomechanical stresses at the encapsulant/rear electrode interface. The addition of thermally conductive two-dimensional hexagonal boron nitride into the polymeric matrix improves the barrier and thermal management properties of the encapsulant. Without any edge sealant, encapsulated devices withstood multifaceted accelerated ageing tests, retaining >80% of their initial efficiency. Our encapsulation is applicable to the most established cell configurations (direct/inverted, mesoscopic/planar), even with temperature-sensitive materials, and extended to semi-transparent cells for building-integrated photovoltaics and Internet of Things systems. The instability of perovskite solar cells hinders their commercialization. Here, authors report an industrially compatible strain-free encapsulation process based on lamination of highly viscoelastic semi-solid/highly viscous liquid encapsulant adhesive to reduce thermomechanical interfacial stress.

Research on corrosion resistance of cast aluminum alloys is reviewed in this article. The effect of the main microstructural features of cast aluminum alloys such as secondary dendrite arm spacing (SDAS), eutectic silicon morphology, grain size, macrosegregation, microsegregation, and intermetallic compounds is discussed. Moreover, the corrosion resistance of cast aluminum alloys obtained by modern manufacturing processes such as semi-solid and additive manufacturing are analyzed. Finally, the protective effects provided by different coatings on the aluminum cast alloys—such as anodized, plasma electrolytic oxidation (PEO), and laser—is reviewed. Some conclusions and future guidelines for future works are proposed.

Deformable semi-solid liquid metal particles (LMP) have emerged as a promising substitute for rigid conductive fillers due to their excellent electrical properties and stable conductance under strain. However, achieving a compact and robust coating of LMP on fibers remains a persistent challenge, mainly due to the incompatibility of conventional coating techniques with LMP. Additionally, the limited durability and absence of initial electrical conductivity of LMP restrict their widespread application. In this study, we propose a solution process that robustly and compactly assembles mechanically durable and initially conductive LMP on fibers. Specifically, we present a shearing-based deposition of polymer-attached LMP followed by additional coating with CNT-attached LMP to create bi-layer LMP composite with exceptional durability, electrical conductivity, stretchability, and biocompatibility on various fibers. The versatility and reliability of this manufacturing strategy for 1D electronics are demonstrated through the development of sewn electrical circuits, smart clothes, stretchable biointerfaced fiber, and multifunctional fiber probes. The mechanical and electrical properties of liquid-metal particle fibers are limited by incompatible coating techniques. Here, Lee et. al. present a solution shearing-based deposition technique for high performance bi-layer stretchable fibers, showcasing applications in smart clothing and 1D bioelectronics.

Bistable display has been a long-awaited goal due to its zero energy cost when maintaining colored or colorless state and electrochromic material has been highly considered as a potential way to achieve bistable display due to its simple structure and possible manipulation. However, it is extremely challenging with insurmountable technical barriers related to traditional electrochromic mechanisms. Herein a prototype for bistable electronic billboard and reader with high energy efficiency is demonstrated with excellent bistability (decay 7% in an hour), reversibility (10 4 cycles), coloration efficiency (430 cm 2  C −1 ) and very short voltage stimulation time (2 ms) for color switching, which greatly outperforms current products. This is achieved by stabilization of redox molecule via intermolecular ion transfer to the supramolecular bonded colorant and further stabilization of the electrochromic molecules in semi-solid media. This promising approach for ultra-energy-efficient display will promote the development of switching molecules, devices and applications in various fields of driving/navigation/industry as display to save energy. For electrochromic materials to reach their full potential for high efficiency bistable displays, technical challenges related to their underlying mechanism must be addressed. Here, the authors, through intelligent molecular design, report a solid bistable device with state-of-the-art performance.

One of the most used additive manufacturing (AM) techniques is fused filament fabrication (FFF), which is primarily used for processing polymers. An interesting strategy to utilize this technique in metal processing is to adapt semisolid processing principles. Herein, low-melting Sn–Bi alloys were investigated to identify the ideal composition and processing conditions for semisolid AM using FFF. For this purpose, thermodynamic simulations were used to characterize the evolution of liquid fractions with temperature, and the results led to the selection of Sn-38Bi alloy (mass/%) for experimental validation. This composition was prepared by casting in an inert environment, followed by thermal analysis. The differential scanning calorimetry results were reasonably consistent with the simulated results. The as-cast Sn-38Bi was extruded to produce a metallic filament. To investigate the microstructural evolution in the semisolid state, samples from the filament were subjected to multiple heat treatments at different temperatures. Semisolid AM for the selected alloy was successfully performed at 170 °C. This process included extrusion and deposition without nozzle clogging or discontinuity formation. Various geometries were successfully fabricated, and the results demonstrated the efficacy of the FFF technique for processing metallic materials. Graphical abstract

Beneficial rhizobacteria promote plant growth and protect plants against phytopathogens. Effective colonization on plant roots is critical for the rhizobacteria to exert beneficial activities. How bacteria migrate swiftly in the soil of semisolid or solid nature remains unclear. Here we report that sucrose, a disaccharide ubiquitously deployed by photosynthetic plants for fixed carbon transport and storage, and abundantly secreted from plant roots, promotes solid surface motility (SSM) and root colonization by Bacillus subtilis through a previously uncharacterized mechanism. Sucrose induces robust SSM by triggering a signaling cascade, first through extracellular synthesis of polymeric levan, which in turn stimulates strong production of surfactin and hyper-flagellation of the cells. B. subtilis poorly colonizes the roots of Arabidopsis thaliana mutants deficient in root-exudation of sucrose, while exogenously added sucrose selectively shapes the rhizomicrobiome associated with the tomato plant roots, promoting specifically bacilli and pseudomonad. We propose that sucrose activates a signaling cascade to trigger SSM and promote rhizosphere colonization by B. subtilis . Our findings also suggest a practicable approach to boost prevalence of beneficial Bacillus species in plant protection.

The atmosphere of Venus remains mysterious, with many outstanding chemical connundra. These include the unexpected presence of ∼10 ppm O₂ in the cloud layers, an unknown composition of large particles in the lower cloud layers, and hard to explain measured vertical abundance profiles of SO₂ and H₂O. We propose a hypothesis for the chemistry in the clouds that largely addresses all of the above anomalies. We include ammonia (NH₃), a key component that has been tentatively detected both by the Venera 8 and Pioneer Venus probes. NH₃ dissolves in some of the sulfuric acid cloud droplets, effectively neutralizing the acid and trapping dissolved SO₂ as ammonium sulfite salts. This trapping of SO₂ in the clouds, together with the release of SO₂ below the clouds as the droplets settle out to higher temperatures, explains the vertical SO₂ abundance anomaly. A consequence of the presence of NH₃ is that some Venus cloud droplets must be semisolid ammonium salt slurries, with a pH of ∼1, which matches Earth acidophile environments, rather than concentrated sulfuric acid. The source of NH₃ is unknown but could involve biological production; if so, then the most energy-efficient NH₃-producing reaction also creates O₂, explaining the detection of O₂ in the cloud layers. Our model therefore predicts that the clouds are more habitable than previously thought, and may be inhabited. Unlike prior atmospheric models, ours does not require forced chemical constraints to match the data. Our hypothesis, guided by existing observations, can be tested by new Venus in situ measurements.