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Vascular cells self-organize into unique structures guided by cell proliferation, migration, and/or differentiation from neighboring cells, mechanical factors, and/or soluble signals. However, the relative contribution of each of these factors remains unclear. Our objective was to develop a computational model to explore the different factors affecting the emerging micropatterns in 2D. This was accomplished by developing a stochastic on-lattice population-based model starting with vascular progenitor cells with the potential to proliferate, migrate, and/or differentiate into either endothelial cells or smooth muscle cells. The simulation results yielded patterns that were qualitatively and quantitatively consistent with experimental observations. Our results suggested that post-differentiation cell migration and proliferation when balanced could generate between 30-70% of each cell type enabling the formation of vascular patterns. Moreover, the cell-to-cell sensing could enhance the robustness of this patterning. These findings computationally supported that 2D patterning is mechanistically similar to current microfluidic platforms that take advantage of the migration-directed self-assembly of mature endothelial and mural cells to generate perfusable 3D vasculature in permissible hydrogel environments and suggest that stem or progenitor cells may not be fully necessary components in many tissue formations like those formed by vasculogenesis.

High‐performance 0D–2D hybrid photodetectors integrated with a crosslinker for direct pattering of quantum dots on the large‐scale synthesized MoS2 layer are reported. In the patterned hybrid structure, QD layers are patterned with a resolution of up to 2 µm, ensuring high precision. Enhanced charge transfer from QDs to 2D materials is confirmed using PL quenching, TR‐PL, and UPS analysis. As a result, the QD/2D hybrid photodetectors with crosslinker‐assisted direct patterning demonstrated a remarkable photoresponsivity of ≈105 A W−1 and a specific detectivity of over 1011 Jones, attributed to the difference in built‐in potential. The crosslinker patterning of QDs opens up potential applications for the photodetectors in highly integrated image sensors and can be further extended to high‐resolution display industries, eliminating unnecessary fabrication processes. [ABSTRACT FROM AUTHOR]

Precise pixel control of quantum dots (QDs) offers unparalleled opportunities for various display applications, such as the OLED and Micro-LED. However, precise selective patterning of QDs is still a challenge due to the lack of a design methodology. Therefore, the aim of this study was thus to develop a photoinitiator-grafted oligomer for "on demand" control of active free radicals to improve the line edge roughness in QD patterning. This photosensitive oligomer was constructed by grafting the photosensitive benzophenone structure onto a phenolic resin oligomer, thus resulting in the confinement of active free radicals and highly selective photolithography. As a proof of concept, we have demonstrated high-quality QD patterns with high resolution and low edge roughness by using direct in situ photolithography. This work opens an avenue for the precise design and synthesis of QD photoresists, improving the precision of QD patterning for display applications. [ABSTRACT FROM AUTHOR]

Flexible electronics with sophisticated 3D architectures enable multidimensional functionalities and multi‐component integration, thus surpassing their 2D counterparts in soft robotics and wearable sensors. Because of its unique metallic and fluidic characteristics, liquid metal (LM) has proven to be an excellent material for fabricating flexible electronics. However, its low viscosity and high surface tension have primarily restricted LM to the creation of 2D‐patterned films on flat surfaces, significantly limiting the complexity and functionality of the resulting flexible devices. In this work, inspired by the capillary‐driven liquid flow in a hierarchical lattice matrix, a 3D patterning method is proposed for LM and extended to the fabrication of porous materials with flexible conductivity. The feasibility and versatility of the proposed method are showcased by fabricating tunable electromagnetic interference shielding materials, programmable 3D circuits, and customizable wearable sensors, highlighting its potential for promoting the development of integrated circuits and wearable electronics. [ABSTRACT FROM AUTHOR]

The selective patterning of gold chloride (AuCl3) dopants on few‐layer molybdenum disulfide (MoS2) flakes is investigated with the objective of manipulating the electrical properties of 2D material‐based devices. MoS2, renowned for its exceptional properties, is doped with AuCl3 via spin coating. The removal of the dopants is achieved using contact‐mode atomic force microscopy (AFM), with control over the extent of dopant obtained by varying the AFM tip's contact force. Scanning electron microscopy and energy‐dispersive X‐ray spectroscopy confirm the patterning of the dopants. The application of this patterning method to MoS2‐based field‐effect transistors results in rectified output characteristics, in contrast to the ohmic behavior observed in pristine and fully coated devices. This method offers a valuable approach for customizing MoS2 surfaces, advancing 2D material‐based electronic devices and next‐generation semiconductor designs with tailored properties. [ABSTRACT FROM AUTHOR]

For the new display technology based on quantum dots (QDs), realizing high-precision arrays of red, green, and blue (RGB) pixels has been a significant research focus at present, aimed at achieving high-quality and high-resolution image displays. However, challenges such as material stability and the variability of process environments complicate the assurance of quality in high-precision patterns. The novel optical patterning technology, exemplified by direct photolithography, is considered a highly promising approach for achieving submicron-level, hyperfine patterning. On the technological level, this method produces patterned quantum dot light-emitting films through a photochemical reaction. Here, we provide a comprehensive review of various methods of QD photolithography patterning, including traditional photolithography, lift off, and direct photolithography, which mainly focused on direct photolithography. This review covers the classification of direct photolithography technologies, summarizes the latest research progress, and discusses future perspectives on the advancement of photolithography technology de-masking. [ABSTRACT FROM AUTHOR]

Quantum dots (QDs) have garnered significant attention in the advanced optoelectronic devices due to their unique luminescent properties, including size-tunable emission, high photoluminescence efficiency, exceptional chromatic purity, and superior photostability. To achieve based high-definition full-color displays, it is critical to develop a precise patterning process capable of accurately depositing red, green, and blue QD subpixels at desired locations with high resolution. Among various patterning techniques, transfer printing has emerged as a promising method for achieving high-definition pixels while preventing cross-contamination between different colored subpixels. This technique involves transferring QD patterns to a target substrate using an elastomeric stamp. This review provides a comprehensive overview of the latest research trends in three types of transfer printing processes: additive-transfer printing, subtractive-transfer printing, and intaglio-transfer printing. We examine the strengths and limitations of each technique and showcase key applications in QD light-emitting diodes that utilize transfer-printed QDs. [ABSTRACT FROM AUTHOR]

The light‐induced control in the fabrication of materials is a field in continuous development. So far, photo‐induced processes have been used mostly for organic polymeric materials. However, there is a recent, increasing interest in exploring the possibility of using these techniques to induce the precipitation of inorganic materials. This perspective paper outlines the main principles of the light‐induced precipitation of inorganic materials, focusing on the recent papers published in this field. The description of the mechanisms and the materials involved in these light‐induced processes highlight their many possibilities and future challenges, which could pave the way for significant advancements in this exciting technology. [ABSTRACT FROM AUTHOR]

The glabrous skin of the rhinarium (naked nose) of many mammalian species exhibits a polygonal pattern of grooves that retain physiological fluid, thereby keeping their nose wet and, among other effects, facilitating the collection of chemosensory molecules. Here, we perform volumetric imaging of whole-mount rhinaria from sequences of embryonic and juvenile cows, dogs, and ferrets. We demonstrate that rhinarial polygonal domains are not placode-derived skin appendages but arise through a self-organized mechanical process consisting of the constrained growth and buckling of the epidermal basal layer, followed by the formation of sharp epidermal creases exactly facing an underlying network of stiff blood vessels. Our numerical simulations show that the mechanical stress generated by excessive epidermal growth concentrates at the positions of vessels that form rigid base points, causing the epidermal layers to move outward and shape domes—akin to arches rising against stiff pillars. Remarkably, this gives rise to a larger length scale (the distance between the vessels) in the surface folding pattern than would otherwise occur in the absence of vessels. These results hint at a concept of "mechanical positional information" by which material properties of anatomical elements can impose local constraints on an otherwise globally self-organized mechanical pattern. In addition, our analyses of the rhinarial patterns in cow clones highlight a substantial level of stochasticity in the pre-pattern of vessels, while our numerical simulations also recapitulate the disruption of the folding pattern in cows affected by a hereditary disorder that causes hyperextensibility of the skin. [Display omitted] • Rhinarial polygonal domains are not placode-derived but mechanically self-organized • The rhinarial skin pattern is mechanically coupled with underlying blood vessels • Epidermal domes rise against stiffer blood vessels—like arches against pillars • Rhinarial folds are as variable among cow clones as among unrelated individuals Dagenais et al. demonstrate that the characteristic polygonal folding patterns on the noses of many mammalian species, such as dogs, ferrets, and cows, emerge via a peculiar self-organizational process involving mechanical positional information encoded by the spatial distribution of stiffness in adjacent tissues. [ABSTRACT FROM AUTHOR]

Defects are inherent in transition metal dichalcogenides and significantly affect their chemical and physical properties. In this study, surface defect electrochemical nanopatterning is proposed as a promising method to tune in a controlled manner the electronic and functional properties of defective MoS₂ thin films. Using parallel electrochemical nanolithography, MoS₂ thin films are patterned, creating sulphur vacancy‐rich active zones alternated with defect‐free regions over a centimetre scale area, with sub‐micrometre spatial resolution. The patterned films display tailored optical and electronic properties due to the formation of sulphur vacancy‐rich areas. Moreover, the effectiveness of defect nanopatterning in tuning functional properties is demonstrated by studying the electrocatalytic activity for the hydrogen evolution reaction. [ABSTRACT FROM AUTHOR]

Homeobox genes are among the most deeply conserved families of transcription factor-encoding genes. Following their discovery in Drosophila, homeobox genes arrived on the Caenorhabditis elegans stage with a vengeance. Between 1988 and 1990, just a few years after their initial discovery in flies and vertebrates, positional cloning and sequence-based searches showed that C. elegans contains HOX cluster genes, an apparent surprise given the simplicity and non-segmented body plan of the nematode, as well as many other non-clustered homeobox genes of all major subfamilies (e.g. LIM, POU, etc.). Not quite 40 years later, we have an exceptionally deep understanding of homeodomain protein expression and function in C. elegans, revealing their prevalent role in nervous system development. In this Spotlight, we provide a historical perspective and a non-comprehensive journey through the C. elegans homeobox field and discuss open questions and future directions. [ABSTRACT FROM AUTHOR]

Many salamanders can completely regenerate a fully functional limb. Limb regeneration is a carefully coordinated process involving several defined stages. One key event during the regeneration process is the patterning of the blastema to inform cells of what they must differentiate into. Although it is known that many genes involved in the initial development of the limb are re-used during regeneration, the exact molecular circuitry involved in this process is not fully understood. Several large-scale transcriptional profiling studies of axolotl limb regeneration have identified many transcription factors that are up-regulated after limb amputation. Sall4 is a transcription factor that has been identified to play essential roles in maintaining cells in an undifferentiated state during development and also plays a unique role in limb development. Inactivation of Sall4 during limb bud development results in defects in anterior-posterior patterning of the limb. Sall4 has been found to be up-regulated during limb regeneration in both Xenopus and salamanders, but to date it function has been untested. We confirmed that Sall4 is up-regulated during limb regeneration in the axolotl using qRT-PCR and identified that it is present in the skin cells and also in cells within the blastema. Using CRISPR technology we microinjected gRNAs specific for Sall4 complexed with cas9 protein into the blastema to specifically knockout Sall4 in blastema cells only. This resulted in limb regenerate defects, including missing digits, fusion of digit elements, and defects in the radius and ulna. This suggests that during regeneration Sall4 may play a similar role in regulating the specification of anterior-proximal skeletal elements. • Sall4 is re-expressed in many cell after injury to the limb. • Knock-down or knock-out of Sall4 during regeneration results in defects in patterning of the regenerate. • Knock-down or knock-out of Sall4 results in defects in expression of key fgf and wnt genes during limb regeneration. [ABSTRACT FROM AUTHOR]

Neural organoids have emerged as valuable tools for studying the developing brain, sparking enthusiasm and driving their adoption in disease modeling, drug screening, and investigating fetal neural development. The increasing popularity of neural organoids as models has led to a wide range of methodologies aimed at continuous improvement and refinement. Consequently, research groups often improve and reconfigure protocols to create region-specific organoids, resulting in diverse phenotypes, including variations in morphology, gene expression, and cell populations. While these improvements are exciting, routine adoptions of such modifications and protocols in the research laboratories are often challenging due to the reiterative empirical testing necessary to validate the cell types generated. To address this challenge, we systematically compare the similarities and differences that exist across published protocols that generates subpallial-specific organoids to date. In this review, we focus specifically on exploring the production of major GABAergic neuronal subtypes, especially Medium Spiny Neurons (MSNs) and Interneurons (INs), from multiple subpallial organoid protocols. Importantly, we look to evaluate the cell type diversity and the molecular pathways manipulated to generate them, thus broadening our understanding of the existing subpallial organoids as well as assessing the in vitro applicability of specific patterning factors. Lastly, we discuss the current challenges and outlook on the improved patterning of region-specific neural organoids. Given the critical roles MSN and IN dysfunction play in neurological disorders, comprehending the GABAergic neurons generated by neural organoids will undoubtedly facilitate clinical translation. [ABSTRACT FROM AUTHOR]

Water-soluble photocrosslinked poly(vinyl alcohol), N-methyl-4(4'-formylstyryl) pyridinium methosulfate acetal (SbQ-PVA) solution was coated onto silver nanowire (AgNW) films to form SbQ-PVA/AgNW composite films by a simple solution process. The optical-electrical properties and morphology of AgNW films with different surface densities before and after coating with SbQ-PVA were analyzed, and the mechanical as well as environmental stability of the AgNW films were compared with that of the SbQ-PVA/AgNW composite films. The results show that the SbQ-PVA coating does not affect the electrical conductivity of the silver nanowire network and also enhances the optical properties, resulting in a high transmittance of about 90% for composite films with sheet resistance as low as about 20 Ω/sq. Meanwhile, the mechanical stability of the SbQ-PVA/AgNW composite films is significantly enhanced, with the resistance value changing by only 1% in 5 000 bending cycle tests, and it can withstand the scratching of 3B pencil. The SbQ-PVA also brings excellent environmental stability to the composite films, which can maintain the resistance and morphology stability for 4 months in atmospheric environment, and it can also be well resisted to the corrosion of acid, alkali, and salt solutions. In addition, the SbQ-PVA/AgNW composite films are able to remain stable in deionized water ultrasonication, and this feature can be utilized with a photomask for one-step patterning of silver nanowire films. SbQ-PVA/AgNW composite films with high photovoltaic performance and stability offer new possibilities to realize high-quality flexible transparent electrodes in a simple, environmentally friendly and efficient way. [ABSTRACT FROM AUTHOR]

The femtosecond laser direct writing of metals has gained significant attention for micro/nanostructuring. Copper (I) oxide nanospheres (NSs), a promising material for multi-photon metallization, can be reduced to copper (Cu) and sintered through near-infrared femtosecond laser pulse irradiation. In this study, we investigated the size effect of copper (I) oxide nanospheres on their morphology when coated on Cu thin films and irradiated by near-infrared femtosecond laser pulses. Three Cu2O NS inks were prepared, consisting of small (φ100 nm), large (φ200 nm), and a mixture of φ100 nm and φ200 nm NSs. A unique phenomenon was observed at low laser pulse energy: both sizes of NSs bonded as single layers when the mixed NSs were used. At higher pulse energies, the small NSs melted readily compared to the large NSs. In comparisons between the large and mixed NSs, some large NSs remained intact, suggesting that the morphology of the NSs can be controlled by varying the concentration of different-sized NSs. Considering the simulation results indicating that the electromagnetic fields between large and small NSs are nearly identical, this differential morphology is likely attributed to the differences in the heat capacity of the NSs. [ABSTRACT FROM AUTHOR]

Anode-free lithium batteries (AFLBs) present an opportunity to eliminate the need for conventional graphite electrodes or excess lithium–metal anodes, thus increasing the cell energy density and streamlining the manufacturing process. However, their attributed poor coulombic efficiency leads to rapid capacity decay, underscoring the importance of achieving stable plating and stripping of Li on the negative electrode for the success of this cell configuration. A promising approach is the utilization of lithiophilic coatings such as silver to mitigate the Li nucleation overpotential on the Cu current collector, thereby improving the process of Li plating/stripping. On the other hand, inkjet printing (IJP) emerges as a promising technique for electrode modification in the manufacturing process of lithium batteries, offering a fast and scalable technology capable of depositing both thin films and patterned structures. In this work, a Fujifilm Dimatix inkjet printer was used to deposit Ag sites on a Cu current collector, aiming to modulate the interfacial electrochemistry of the system. Samples were fabricated with varying areas of coverage and the electrochemical performance of the system was systematically evaluated from bare Cu (non-lithiophilic) to a designed pattern (partially lithiophilic) and the fully coated thin film case (lithiophilic). Increasing lithiophilicity resulted in lower charge transfer resistance, higher exchange current density and reduced Li nucleation overpotential (from 55.75 mV for bare Cu to 13.5 mV for the fully coated case). Enhanced half-cell cyclability and higher coulombic efficiency were also achieved (91.22% CE over 76 cycles for bare Cu, 97.01% CE over 250 cycles for the fully coated case), alongside more uniform lithium deposition and fewer macroscopic irregularities. Moreover, our observations demonstrated that surface patterning through inkjet printing could represent an innovative, easy and scalable strategy to provide preferential Li nucleation sites to guide the subsequent Li deposition. [ABSTRACT FROM AUTHOR]

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Vascular cells self-organize into unique structures guided by cell proliferation, migration, and/or differentiation from neighboring cells, mechanical factors, and/or soluble signals. However, the relative contribution of each of these factors remains unclear. Our objective was to develop a computational model to explore the different factors affecting the emerging micropatterns in 2D. This was accomplished by developing a stochastic on-lattice population-based model starting with vascular progenitor cells with the potential to proliferate, migrate, and/or differentiate into either endothelial cells or smooth muscle cells. The simulation results yielded patterns that were qualitatively and quantitatively consistent with experimental observations. Our results suggested that post-differentiation cell migration and proliferation when balanced could generate between 30–70% of each cell type enabling the formation of vascular patterns. Moreover, the cell-to-cell sensing could enhance the robustness of this patterning. These findings computationally supported that 2D patterning is mechanistically similar to current microfluidic platforms that take advantage of the migration-directed self-assembly of mature endothelial and mural cells to generate perfusable 3D vasculature in permissible hydrogel environments and suggest that stem or progenitor cells may not be fully necessary components in many tissue formations like those formed by vasculogenesis.

Quasi‐2D Ruddlesden–Popper perovskite (RPP) have surfaced as a promising candidate for light emitting diodes (LEDs) due to its outstanding optoelectronic properties. However, a reliable approach for patterning RPPs remains elusive due to the use of polar solvents in lithographic processes, which can damage the RPP. Here, a reliable and damage‐free dry micropatterning method of RPPs is reported, which also offers a cost/time advantage compared to conventional patterning methods. The sharp edges of high aspect ratio silicon micropillars are used to cut RPPs to a pre‐defined shape and then the cut RPPs are delaminated to obtain a patterned array of RPPs. The resultant patterned array exhibits no sign of degradation or discernable difference between adjacent pixels, achieving a ≈100% yield. The obtained array is utilized to fabricate a pixelated LED where a sharp electroluminescence (EL) spectrum peaking at 410 nm with full‐width‐at‐half‐maximum (FWHM) of 10 nm is observed. The pixelated devices demonstrate the potential to suppress EQE drops as the pixel size decreases, attributed to both the damage‐free micropatterning process and the defect tolerance of RPPs. Moreover, further improvements of the patterning method are demonstrated to avoid parasitic emission and suggest a promising strategy to fabricate pixel‐accessible micro‐LEDs. [ABSTRACT FROM AUTHOR]

Much of the striking diversity of life on Earth has arisen from variations in the way that the same molecules and networks operate during development to shape and pattern tissues and organs into different morphologies. However, we still understand very little about the potential for diversification exhibited by different, highly conserved mechanisms during evolution, or, conversely, the constraints that they place on evolution. With the aim of steering the field in new directions, we focus on morphogen-mediated patterning and growth as a case study to demonstrate how conserved developmental mechanisms can adapt during evolution to drive morphological diversification and optimise functionality, and to illustrate how evolution algorithms and computational tools can be used alongside experiments to provide insights into how these conserved mechanisms can evolve. We first introduce key conserved properties of morphogen-driven patterning mechanisms, before summarising comparative studies that exemplify how changes in the spatiotemporal expression and signalling levels of morphogens impact the diversification of organ size, shape and patterning in nature. Finally, we detail how theoretical frameworks can be used in conjunction with experiments to probe the role of morphogen driven patterning mechanisms in evolution. We conclude that morphogen-mediated patterning is an excellent model system and offers a generally applicable framework to investigate the evolution of developmental mechanisms. [ABSTRACT FROM AUTHOR]

Metal nanoparticles (MNPs) stand out owing to conspicuous catalytic activity, optical and electromagnetic properties, with applications ranging from photocatalysis to biosensor and photoelectric devices. Although photocatalysis with TiO2 has emerged as a promising technique for preparing MNPs, the low photocatalytic efficiency of TiO2 limits its practical utilization. Herein, a rapid photoreduction approach is presented to prepare MNPs under UV and visible light based on polydopamine (PDA)/TiO2 composite surface. It found that the PDA‐modified TiO2 substrate can greatly enhance the photocatalytic efficiency and stability of MNPs, leading to rapid and highly‐controllable preparation of MNPs. By this method, various Ag, Au, and Pd patterns with controllable metallization degree can be easily fabricated. In addition, the substrate can be effectively recycled through rapid photobleaching. This method will have a promising future in the preparation of MNPs for various applications. [ABSTRACT FROM AUTHOR]

Executive function (EF) skills are consistently associated with global mathematics assessments. However, less is known about which specific mathematics skills invoke EF in early childhood. We adapted batteries of EF, numerical, and patterning tasks to be conducted via synchronous video conferencing with typically developing 4‐year‐old children (N = 115, 56.6% female, 85.2% White, non‐Hispanic, 7.8% Multiracial, 0.9% Hispanic, 0.9% Black, 1.7% American Indian/Alaska Native, 2.6% Asian and 0.9% missing) from primarily upper middle class households (maternal education range: some college to graduate or professional degree, mode = graduate or professional degree) in the United States. We found feasibility of remote adaptation varied greatly by task. Just over half of enrolled children (57.02%) completed all tasks and there were higher rates of missingness compared to an in‐person sample with a similar age range collected in schools. Nonetheless, working memory predicted various mathematics skills, including patterning, verbal counting, and number comparison, controlling for age and maternal education. Relations between cognitive flexibility and patterning varied across model specifications. Overall, these findings provide insight into the costs and benefits of remotely administered direct assessments of EF and mathematics in early childhood and add to the growing body of literature suggesting working memory plays an important role in several foundational early mathematics skills. Suggestions are offered for remote assessment with preschoolers. Highlights: Executive function and mathematics tasks were adapted for remote use and associations among skill sets were examined.Remotely administered data collection sessions had higher rates of missingness than comparable in‐person studies.Findings replicate and extend prior work on the associations between working memory and patterning, verbal counting, and number comparison in a remote setting. [ABSTRACT FROM AUTHOR]

Animal body plans are established during embryonic development by the Hox genes. This patterning process relies on the differential expression of Hox genes along the head-to-tail axis. Hox spatial collinearity refers to the relationship between the organization of Hox genes in clusters and the differential Hox expression, whereby the relative order of the Hox genes within a cluster mirrors the spatial sequence of expression in the developing embryo. In vertebrates, the cluster organization is also associated with the timing of Hox activation, which harmonizes Hox expression with the progressive emergence of axial tissues. Thereby, in vertebrates, Hox temporal collinearity is intimately linked to Hox spatial collinearity. Understanding the mechanisms contributing to Hox temporal and spatial collinearity is thus key to the comprehension of vertebrate patterning. Here, we provide an overview of the main discoveries pertaining to the mechanisms of Hox spatial-temporal collinearity. [ABSTRACT FROM AUTHOR]

Four-dimensional (4D) printing adds the dimension of time to 3D-printed specimens, causing movement when external stimuli are applied. This movement enables applications across various fields, including the soft robotics, aerospace, apparel, and automotive industries. Traditionally, 4D printing has utilized special materials such as shape-memory polymers (SMPs) or shape-memory alloys (SMAs) to achieve this movement. This study explores a novel approach to 4D printing by applying microcellular foaming processes (MCPs) to 3D printing. This study primarily aims to design and fabricate patterned specimens using common materials, such as PLA, through 3D printing and to analyze their dynamic behavior under various foaming conditions. To demonstrate the potential applications of this technology, the degree of bending was measured by controlling the patterning and foaming conditions. The 3D-printed specimens with microcellular foaming exhibited predictable deformations owing to the asymmetric expansion caused by differential gas saturation. The results confirm that 4D printing can be realized using conventional materials without the need for smart materials and can introduce foaming processes as a new external stimulus. This study highlights the potential of combining 3D printing with microcellular foaming for advanced 4D printing applications. [ABSTRACT FROM AUTHOR]

Branching morphogenesis is a characteristic feature of many essential organs, such as the lung and kidney, and most glands, and is the net result of two tissue behaviors: branch point initiation and elongation. Each branched organ has a distinct architecture customized to its physiological function, but how patterning occurs in these ramified tubular structures is a fundamental problem of development. Here, we use quantitative 3D morphometrics, timelapse imaging, manipulation of ex vivo cultured mouse embryonic organs and mice deficient in the planar cell polarity component Vangl2 to address this question in the developing mammary gland. Our results show that the embryonic epithelial trees are highly complex in topology owing to the flexible use of two distinct modes of branch point initiation: lateral branching and tip bifurcation. This non-stereotypy was contrasted by the remarkably constant average branch frequency, indicating a ductal growth invariant, yet stochastic, propensity to branch. The probability of branching was malleable and could be tuned by manipulating the Fgf10 and Tgfβ1 pathways. Finally, our in vivo data and ex vivo time-lapse imaging suggest the involvement of tissue rearrangements in mammary branch elongation. [ABSTRACT FROM AUTHOR]

This study aims to establish and optimize a process for the fabrication of 3D microstructures of the biocompatible polymer Parylene C using hot embossing techniques. The different process parameters such as embossing temperature, embossing force, demolding temperature and speed, and the usage of a release agent were optimized, utilizing adhesive micropillars as a use case. To enhance compatibility with conventional semiconductor fabrication techniques, hot embossing of Parylene C was adapted from conventional stainless steel substrates to silicon chip platforms. Furthermore, this adaptation included an investigation of the effects of the hot embossing process on metal layers embedded in the Parylene C, ensuring compatibility with the ultra-thin Parylene printed circuit board (PCB) demonstrated previously. To evaluate the produced microstructures, a combination of characterization methods was employed, including light microscopy (LM) and scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR). These methods provided comprehensive insights into the morphological, chemical, and structural properties of the embossed Parylene C. Considering the improved results compared to existing patterning techniques for Parylene C like plasma etching or laser ablation, the developed hot embossing approach yields a superior structural integrity, characterized by increased feature resolution and enhanced sidewall smoothness. These advancements render the method particularly suitable for diverse applications, including but not limited to, sensor optical components, adhesive interfaces for medical wearables, and microfluidic systems. [ABSTRACT FROM AUTHOR]

Researchers agree that both domain‐general skills and domain‐specific skills contribute to mathematics knowledge, but questions arise as to which skills can and should be trained to improve children's learning outcomes. In this article, we synthesize research on training three domain‐general constructs in early childhood (patterning skills, working memory, and spatial reasoning) and their causal links to mathematics knowledge. The results are clear: Practice with these domain‐general tasks is unlikely to transfer to higher scores on measures of mathematics knowledge, especially for preschool‐aged children. Based on this evidence, we argue against using isolated domain‐general training to enhance math knowledge in early childhood. We offer recommendations for researchers and practitioners to optimize best practices in this area. [ABSTRACT FROM AUTHOR]

In this work, 2D simulations of stainless steel nitriding through a mask were performed with two configurations: with and without lateral adsorption under the mask, depending on the strength of the mask adhesion. The stress-induced diffusion and trapping–detrapping process are included as the main mechanisms of nitrogen mass transport. The main focus is on the analysis of the swelling process, which affects the expansion of the material. The surface concentration profiles and topographical profiles along the surface are calculated and compared with experimentally registered ones taken from the literature, and they show a good agreement. This allows for estimation of the values of model parameters. Because nitriding processes takes place in vertical and horizontal directions, the anisotropic aspect of nitriding are analyzed. It is shown that the adherence of the mask significantly influences the topographical profile and the anisotropy of nitriding, because in the case of a weakly adhered mask, a lateral adsorption process takes place under the mask. The influence of swelling and anisotropy in the case of pattern nitriding in small dimensions is discussed. [ABSTRACT FROM AUTHOR]

Patterning offers an efficient way to quantitatively enhance and enlarge material properties and functionalities, offering unprecedented opportunities for innovation in various scientific domains. By precisely controlling the spatial arrangement of materials at the micro‐ and nanoscale, patterning enables the exploitation of inherent material properties in novel ways. In addition, it generates new properties, leading to the development of advanced devices and applications. This article highlights the significant contributions of spatially controlled patterning in chemistry, particularly in generating new functional properties and devices, discussing some representative articles. Examples include the use of unconventional patterning techniques for surface functionalization, as well as the application of spatial confinement in improving material properties and controlling crystallization processes. Furthermore, the discussion extends to creating new devices, such as optical storage media and sensors, through spatial organization of materials. [ABSTRACT FROM AUTHOR]

Stretchable electrodes have emerged as a promising technology for soft robotics and wearable devices. One fabrication method that guarantees sustained elasticity and high conductivity is directly filling or printing an elastic substrate with liquid metal (LM). However, it is difficult to create patterns with complex or 3D shapes, such as hole patterning, integration electrodes, and flexible breadboards. Therefore, a simple and effective patterning method for fabricating 3D stretchable electronics using LM electrodes is proposed in this study. The LM‐infused sponge electrode is fabricated by loading LM onto a polydimethylsiloxane (PDMS) sponge, which is fabricated using the salt‐leaching method in PDMS patterned by replica molding. The LM‐infused sponge electrode exhibits a minimal change in terms of resistivity under strain, bending, and twisting (∆R < 0.01 Ω cm−1). This enables various devices to be driven by the production of flexible breadboards, which makes it possible to integrate the proposed model into commercial electronics. Finally, a stretchable tactile sensor (self‐capacitive and self‐powered) is fabricated by integrating stretchable electrodes using only the LM‐infused sponges. In the future, stretchable electrodes fabricated in this manner can be used in various applications, such as soft robots and wearable devices. [ABSTRACT FROM AUTHOR]

Transcription often occurs in bursts as gene promoters switch stochastically between active and inactive states. Enhancers can dictate transcriptional activity in animal development through the modulation of burst frequency, duration, or amplitude. Previous studies observed that different enhancers can achieve a wide range of transcriptional outputs through the same strategies of bursting control. For example, in Berrocal et al., 2020, we showed that despite responding to different transcription factors, all even-skipped enhancers increase transcription by upregulating burst frequency and amplitude while burst duration remains largely constant. These shared bursting strategies suggest that a unified molecular mechanism constraints how enhancers modulate transcriptional output. Alternatively, different enhancers could have converged on the same bursting control strategy because of natural selection favoring one of these particular strategies. To distinguish between these two scenarios, we compared transcriptional bursting between endogenous and ectopic gene expression patterns. Because enhancers act under different regulatory inputs in ectopic patterns, dissimilar bursting control strategies between endogenous and ectopic patterns would suggest that enhancers adapted their bursting strategies to their trans-regulatory environment. Here, we generated ectopic even-skipped transcription patterns in fruit fly embryos and discovered that bursting strategies remain consistent in endogenous and ectopic even-skipped expression. These results provide evidence for a unified molecular mechanism shaping even-skipped bursting strategies and serve as a starting point to uncover the realm of strategies employed by other enhancers.

This paper presents etching process developments using a single-side gaseous etch process based on the thermal reaction of poly-Silicon and the etching gas (molecular fluorine), that results in a high etching selectivity between layers, and a high etching rate. This work was carried out in the context of the development of solar cell architectures beyond PERC and TOPCon, where more sophisticated etching steps are required in order to accurately pattern poly-silicon layers across the wafer surface.

Anodization enables nano-structure fabrication through electrochemical parameter control. While various approaches exist for creating localized or patterned oxide layers, many are complex and time-consuming. This study adopted a commercial 3D printer for high-speed (1 mm/s) anodization, forming TiO2 nanotube layers on Ti substrates in G-code-designed patterns. Comprehensive characterization using XRD, SEM, XPS, and simulated electric field distribution analysis revealed well-defined nanostructures and provided insights into the formation mechanism. Furthermore, viologen-anchored TiO2 showed significantly improved electrochromic performance compared to pristine TiO2, with a higher reflectance difference (46.2% vs. 6.85%). This 3D printing-anodization hybrid method offers a rapid approach to fabricating patterned TiO2 nanostructures, showing promise for electrochromic devices with enhanced optical modulation capabilities.

Understanding the principles underlying the design of robust, yet flexible patterning systems is a key problem in developmental biology. In the Drosophila wing, Hedgehog (Hh) signaling determines patterning outputs using dynamical properties of the Hh gradient. In particular, the pattern of collier (col) is established by the steady-state Hh gradient, whereas the pattern of decapentaplegic (dpp), is established by a transient gradient of Hh known as the Hh overshoot. Here, we use mathematical modeling to suggest that this dynamical interpretation of the Hh gradient results in specific robustness and precision properties. For instance, the location of the anterior border of col, which is subject to self-enhanced ligand degradation is more robustly specified than that of dpp to changes in morphogen dosage, and we provide experimental evidence of this prediction. However, the anterior border of dpp expression pattern, which is established by the overshoot gradient is much more precise to what would be expected by the steady-state gradient. Therefore, the dynamical interpretation of Hh signaling offers tradeoffs between robustness and precision to establish tunable patterning properties in a target-specific manner.

Abstract This mini‐review explores the evolution of image sensors, essential electronic components increasingly integrated into daily life. Traditional manufacturing methods for image sensors and photodetectors, employing high carbon footprint techniques like thermal evaporation and chemical vapor deposition, are being replaced by environmentally conscious solution processing. Organic and Colloidal Quantum Dot‐based image sensors emerge as promising candidates, aligning with the shift toward solution‐based device integration. This review provides insights into the working principles of photodetectors and image sensors, summarizing relevant materials and fabrication approaches. Additionally, it delves into the detailed exploration of pixelated patterning techniques and their potential applications in the realm of solution‐processed image sensor fabrication.

Multi-scale organization of molecular and living components is one of the most critical parameters that regulate charge transport in electroactive systems-whether abiotic, biotic, or hybrid interfaces. In this article, an overview of the current state-of-the-art for controlling molecular order, nanoscale assembly, microstructure domains, and macroscale architectures of electroactive organic interfaces used for biomedical applications is provided. Discussed herein are the leading strategies and challenges to date for engineering the multi-scale organization of electroactive organic materials, including biomolecule-based materials, synthetic conjugated molecules, polymers, and their biohybrid analogs. Importantly, this review provides a unique discussion on how the dependence of conduction phenomena on structural organization is observed for electroactive organic materials, as well as for their living counterparts in electrogenic tissues and biotic-abiotic interfaces. Expansion of fabrication capabilities that enable higher resolution and throughput for the engineering of ordered, patterned, and architecture electroactive systems will significantly impact the future of bioelectronic technologies for medical devices, bioinspired harvesting platforms, and in vitro models of electroactive tissues. In summary, this article presents how ordering at multiple scales is important for modulating transport in both the electroactive organic, abiotic, and living components of bioelectronic systems.

The lateral hypothalamus (LH) has a heterogeneous cytoarchitectonic organization that has not been elucidated in detail. In this work, we analyzed within the framework of the prosomeric model the differential expression pattern of 59 molecular markers along the ventrodorsal dimension of the medial forebrain bundle in the mouse, considering basal and alar plate subregions of the LH. We found five basal (LH1-LH5) and four alar (LH6-LH9) molecularly distinct sectors of the LH with neuronal cell groups that correlate in topography with previously postulated alar and basal hypothalamic progenitor domains. Most peptidergic populations were restricted to one of these LH sectors though some may have dispersed into a neighboring sector. For instance, histaminergic Hdc-positive neurons were mostly contained within the basal LH3, Nts (neurotensin)- and Tac2 (tachykinin 2)-expressing cells lie strictly within LH4, Hcrt (hypocretin/orexin)-positive and Pmch (pro-melanin-concentrating hormone)-positive neurons appeared within separate LH5 subdivisions, Pnoc (prepronociceptin)-expressing cells were mainly restricted to LH6, and Sst (somatostatin)-positive cells were identified within the LH7 sector. The alar LH9 sector, a component of the Foxg1-positive telencephalo-opto-hypothalamic border region, selectively contained Satb2-expressing cells. Published studies of rodent LH subdivisions have not described the observed pattern. Our genoarchitectonic map should aid in systematic approaches to elucidate LH connectivity and function.

Patterning metal halide perovskite thin films is a necessary pathway to expand their optoelectronic applications. However, developing a suitable patterning technique is challenging as conventional lithographic processes are either detrimental to the perovskite layer or lack compatibility with scalable fabrication processes used in the manufacturing of printed electronics. In this work, a complete bottom‐up patterning method is proposed based on de‐wetting from a hydrophobic molecular template, which constrains the perovskite ink to directly crystallize in selected hydrophilic regions. Octadecylphosphonic acid molecules are used as the hydrophobic template and are effectively transferred onto metal‐oxide substrates via micro‐contact printing. This allows for a low‐cost, rapid, and scalable micron‐scale patterning of perovskite thin films. Facile control over light transmittance is demonstrated by adjusting the amount of exposed area and the corresponding spectral shape changes shift the film's appearance toward being color‐neutral. Finally, the method's scalability and versatility are shown by fabricating 25 cm2 patterned films over rigid and flexible substrates. [ABSTRACT FROM AUTHOR]

Over the past decade, the power conversion efficiency of halide perovskite solar cells has shown a rapid increase to 26.1%. The significant efficiency growth and the relative simplification of the technology for obtaining thin-film solar cells due to liquid printing methods determine the high potential for the low-cost perovskite solar cells manufacturing. However, efficient use of cell geometry is comparable to the size of standard crystalline-Si wafers (156:156 mm and more). Therefore, modular geometry similar to amorphous-Si solar cell approaches is used to scale perovskite solar cells. Serial electrical connection of thin-film cells requires precise processing of the conductive layers that form the device p-i-n structure. The subject of research is the development of a full pulsed laser scribing cycle for inverted perovskite solar cells. In this work, we propose a study of a laser-patterning technology In2O3:SnO2 (ITO) conductive layer and a photoactive perovskite layer Cs0,2(CH(NH2)2)0,8PbI3. Process regimes of transparent conducting electrodes based on ITO and halide perovskite layer Cs0,2(CH(NH2)2)0,8PbI3 laser patterning were obtained. The optimal parameters for the multipass mode processing of ITO and perovskite layer were determined. The cell was electrically isolated at a scribe line width of 30 μm. [ABSTRACT FROM AUTHOR]