Docosahexaenoic acid (DHA) promotes recovery from postoperative ileus and the repair of the injured intestinal barrier through mast cell-nerve crosstalk.

The objective of this study was to investigate the neuroimmune mechanisms implicated in the enhancement of gastrointestinal function through the administration of oral DHA. Mast cell-deficient mice (KitW-sh) and C57BL/6 mice were used to establish postoperative ileus (POI) models. To further validate our findings, we conducted noncontact coculture experiments involving dorsal root ganglion (DRG) cells, bone marrow-derived mast cells (BMMCs) and T84 cells. Furthermore, the results obtained from investigations conducted on animals and cells were subsequently validated through clinical trials. The administration of oral DHA had ameliorative effects on intestinal barrier injury and postoperative ileus. In a mechanistic manner, the anti-inflammatory effect of DHA was achieved through the activation of transient receptor potential ankyrin 1 (TRPA1) on DRG cells, resulting in the stabilization of mast cells and increasing interleukin 10 (IL-10) secretion in mast cells. Furthermore, the activation of the pro-repair WNT1-inducible signaling protein 1 (WISP-1) signaling pathways by mast cell-derived IL-10 resulted in an enhancement of the intestinal barrier integrity. The current study demonstrated that the neuroimmune interaction between mast cells and nerves played a crucial role in the process of oral DHA improving the intestinal barrier integrity of POI, which further triggered the activation of CREB/WISP-1 signaling in intestinal mucosal cells.

Programmable, High-resolution Printing of Spatially Graded Perovskites for Multispectral Photodetectors.

Micro/nanostructured perovskites with spatially graded compositions and bandgaps are promising in filter-free, chip-level multispectral, and hyperspectral detection. However, achieving high-resolution patterning of perovskites with controlled graded compositions is challenging. Here, a programmable mixed electrohydrodynamic printing (M-ePrinting) technique is presented to realize the one-step direct-printing of arbitrary spatially graded perovskite micro/nanopatterns for the first time. M-ePrinting enables in situ mixing and ejection of solutions with controlled composition/bandgap by programmatically varying driving voltage applied to a multichannel nozzle. Composition can be graded over a single dot, line or complex pattern, and the printed feature size is down to 1 µm, which is the highest printing resolution of graded patterns to the knowledge. Photodetectors based on micro/nanostructured perovskites with halide ions gradually varying from Br to I are constructed, which successfully achieve multispectral detection and full-color imaging, with a high detectivity and responsivity of 3.27 × 1015 Jones and 69.88 A W-1, respectively. The presented method provides a versatile and competitive approach for such miniaturized bandgap-tunable perovskite spectrometer platforms and artificial vision systems, and also opens new avenues for the digital fabrication of composition-programmable structures.

Systematic evaluation of guidelines for laparoscopic surgery and endoscopic management for colon cancer.

PURPOSE: To understand the methodological quality of recent guidelines for laparoscopic surgery and endoscopic management for colon cancer and to analyze the heterogeneity and possible reasons for the main recommendations. METHODS: A systematic and comprehensive search of databases and relevant websites was conducted to collect guidelines for laparoscopic surgery for colon cancer in the last 10 years that met the inclusion criteria. The AGREE II manual was used to evaluate the included guidelines and to assess and analyze the heterogeneity and reasons for key recommendations about the surgery. RESULTS: A total of fifteen guidelines were included in this study. Only two guidelines had an overall score greater than 60% and were recommended for clinical use. Eleven guidelines had an overall score of 30-60%, and two guidelines had an overall score of less than 30%. Further analysis of the reasons for heterogeneity in the guideline recommendations and evidence was performed for nine guidelines. This study found that only 36.1% of the evidence levels recommended in the guidelines were high. Significant heterogeneity exists in the main recommendations, mainly because the relevant content is not mentioned or described in detail. CONCLUSION: The quality of guidelines for laparoscopic colon cancer surgery is variable, and there is significant heterogeneity among key recommendations. And the level of evidence underlying the recommendations was generally not high. Further guideline updates should address the causes of the above heterogeneity.

High density, addressable electrohydrodynamic printhead made of a silicon plate and polymer nozzle structure.

Electrohydrodynamic (EHD) printing is a promising micro/nanofabrication technique, due to its ultra-high resolution and wide material applicability. However, it suffers from low printing efficiency which urgently calls for a high density and addressable nozzle array. This paper presents a nozzle array chip made of a silicon plate and polymer nozzle structure, where the large silicon plate is conducive to a uniform spatial electric field distribution, and the polymer SU8 nozzle can inhibit tip discharge due to its insulating character and liquid flooding as SU8 is hydrophobic. By carefully designing the nozzle array structure via simulation, and fabricating it through MEMS technology, a high-density nozzle array chip has been achieved which can generate very uniform dots without crosstalk. Meanwhile, by adding extractors underneath the nozzle array, and utilizing a digital switch array to tune their on/off state, addressable printing has been realized. This novel printhead design has solved the discharge, liquid flooding, and crosstalk behavior in EHD nozzle arrays, and is compatible with traditional silicon-based MEMS technology, which will promote the practical applications of EHD printing in micro/nanoelectronics, biomedical/energy devices, etc.

Mode-tunable, micro/nanoscale electrohydrodynamic deposition techniques for optoelectronic device fabrication.

The rapid development of fascinating new optoelectronic materials and devices calls for the innovative production of micro/nanostructures in a high-resolution, large-scale, low-cost fashion, preferably compatible with flexible/wearable applications. Powerful electrohydrodynamic (EHD) deposition techniques, which generate micro/nanostructures using high electrical forces, exhibit unique advantages in high printing resolution (<1 µm), tunable printing modes (electrospray for films, electrospinning for fibers and EHD jet printing for dots), and wide material applicability (viscosity 1-10 000 cps), making them attractive in the fabrication of high-density and high-tech optoelectronic devices. This review highlights recent advances related to EHD-deposited optoelectronics, ranging from solar cells, photodetectors, and light-emitting diodes, to transparent electrodes, with detailed descriptions of the EHD-based jetting mechanism, ink formulation requirements and corresponding jetting modes to obtain functional micro/nanostructures. Finally, a brief summary and an outlook on the future perspectives are proposed.

SNHG3 Affects Gastric Cancer Development by Regulating SEPT9 Methylation.

Background: Gastric cancer (GC) is a common malignancy that can be formed by methylation-induced deactivation of tumor silencer genes, which is one of the key mechanisms of tumorigenesis. SEPT9 methylation, a symptomatic marker for tumors, can downregulate gene expression. Long noncoding RNA small nucleolar host gene 3 (lncRNA SNHG3) is a new type of lncRNA related to cancer. Our study investigated the mechanism of SNHG3 regulation of SEPT9 methylation and its effects on the growth, metastasis, and spread of gastric cancer cells. Methods: Quantitative real-time PCR (qRT-PCR) was used to detect SNHG3 and miR-448 in gastric cancer, and a dual-luciferase experiment verified the effects of SNHG3, miR-448, and DNMT1. After abnormally expressing SNHG3, miR-448, and DNMT1 alone or together, methylation-specific PCR was performed to determine the methylation of SEPT9, Western blotting was performed to detect the expression of DNA methyltransferase 1 (DNMT1) and SEPT9, and Transwell, scratch, and CCK-8 assays were performed to reveal the invasion, migration, and cell growth of gastric cancer cells. Results: We found that SNHG3 was upregulated in gastric cancer and that SNHG3 knockdown or miR-448 overexpression inhibited SEP9 methylation and therefore increased its expression, thereby inhibiting the growth, metastasis, and spread of gastric cancer cells. Conclusion: Our study indicates that SNHG3 regulates SEPT9 methylation by targeting miR-448/DNMT1 and subsequently affecting the occurrence and development of gastric cancer.

Distinct Performance of Methylated SEPT9 in Upper and Lower Gastrointestinal Cancers and Combined Detection with Protein Markers.

Background: The performance of methylated SEPT9 (mSEPT9) in lower gastrointestinal (GI) cancer (colorectal cancer) has been extensively investigated; however, its performance in upper GI cancer (esophageal cancer and gastric cancer) and the comparison with lower GI cancer have rarely been studied. Methods: A total of 1854 subjects, including 344 upper GI cancer patients, 459 lower GI cancer patients, and 1051 noncancer subjects, were recruited in this prospective cohort study. A modified single polymerase chain reaction test for detecting mSEPT9 was used for plasma detection. Results: The sensitivity of mSEPT9 for upper and lower GI cancers was 45.3% and 74.8%, and the corresponding specificities were 85.6% and 86.5%, with areas under curve (AUC) of 0.71 and 0.80, respectively. mSEPT9 exhibited lower sensitivity in stage I than stage II-IV cancer, while no difference in sensitivity was observed for different locations in upper or lower GI cancer. No difference in sensitivity was found among gross classifications, pathological classifications, and differentiation in upper GI cancer, but a higher sensitivity in infiltrative cancer and moderate and poorly differentiated cancers was observed in the lower GI. No difference in sensitivity was found between male and female in both cancers, while sensitivity increased with age for both cancers. Cancer antigen 724 (CA724) showed the highest sensitivity for upper GI cancers, and carcinoembryonic antigen (CEA) showed the highest sensitivity for lower GI cancers. The combination of CA724 with mSEPT9 increased the sensitivity to 67.5% in upper GI cancers, and the combination of mSEPT9 with CEA increased the sensitivity to 85.4% in lower GI cancers, with an AUC of 0.90 and 0.95, respectively. Conclusions: mSEPT9 exhibited a higher sensitivity in lower GI cancers than upper GI cancers. The combination of mSEPT9 with protein markers significantly enhanced the detection sensitivity in both cancers.

Cholesterol crystals activate NLRP3 inflammasomes and promote gallstone formation by increasing mucin secretion.

Cholesterol crystals participate in cholesterol nucleation; however, the role of cholesterol crystals in gallstone development is unknown. Mucin secretion contributes to increased size of gallstones. Cholesterol crystals activate inflammasomes and participate in many sterile inflammation related human diseases. We investigated the role of cholesterol crystals and mucins in sterile inflammation and gallstone enlargement. We found that expression of mucin 5AC (MUC5AC), NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) and interleukin-1b (IL-1b) was increased significantly in tissues adjacent to gallstones. Experiments in vitro showed that cholesterol crystals promote MUC5AC secretion; they also increase expression of NLRP3, NLR family CARD domain-containing 4 (NLRC4), apoptosis-associated speck-like protein containing caspase recruitment domain (ASC), and cleaved caspase-1 in biliary epithelial cells. Inhibition of Inflammasomes by NLRP3, ASC or caspase-1 small interfering RNAs reduced MUC5AC secretion. Also, the IL-1 receptor antagonist, IL1RA, and caspase-1 inhibitor, Ac-YVAD, both inhibited MUC5AC secretion induced by cholesterol crystals. We found that inflammasome activation participates in cholesterol crystal induced mucin secretion and gallstone development.

Flexible Metamaterial Electronics.

Over the last decade, extensive efforts have been made on utilizing advanced materials and structures to improve the properties and functionalities of flexible electronics. While the conventional ways are approaching their natural limits, a revolutionary strategy, namely metamaterials, is emerging toward engineering structural materials to break the existing fetters. Metamaterials exhibit supernatural physical behaviors, in aspects of mechanical, optical, thermal, acoustic, and electronic properties that are inaccessible in natural materials, such as tunable stiffness or Poisson's ratio, manipulating electromagnetic or elastic waves, and topological and programmable morphability. These salient merits motivate metamaterials as a brand-new research direction and have inspired extensive innovative applications in flexible electronics. Here, such a groundbreaking interdisciplinary field is first coined as "flexible metamaterial electronics," focusing on enhancing and innovating functionalities of flexible electronics via the design of metamaterials. Herein, the latest progress and trends in this infant field are reviewed while highlighting their potential value. First, a brief overview starts with introducing the combination of metamaterials and flexible electronics. Then, the developed applications are discussed, such as self-adaptive deformability, ultrahigh sensitivity, and multidisciplinary functionality, followed by the discussion of potential prospects. Finally, the challenges and opportunities facing flexible metamaterial electronics to advance this cutting-edge field are summarized.

Critical Size/Viscosity for Coffee-Ring-Free Printing of Perovskite Micro/Nanopatterns.

Inkjet printing is the most encouraging method for patterning and integrating perovskite materials into microminiature application scenarios. However, it is still challenging to achieve high-resolution, coffee-ring-free, and perfect crystallized patterns. Here, a strategy based on powerful electrohydrodynamic printing and droplet viscosity-size coordinate regulation is developed to solve the above problems. By adding a long-chain polymer poly(vinylpyrrolidone) (PVP) into perovskite precursor to tune ink viscosity and introducing electrohydrodynamic printing to print the high-viscosity ink into droplets of different sizes, we can manipulate the inside flowing resistance and outside evaporation rate of a droplet, thus revealing a critical size/viscosity under which the coffee ring effect is inhibited, showing immense potential and significance for high-quality patterning. In addition, the long-chain polymer benefits droplet spatial limitation and uniform crystallization. The as-printed luminous patterns demonstrate high resolution (structure size ∼1 µm), excellent brightness, pleasant uniformity, and fascinating compatibility with flexible substrates, which is promising for future perovskite optoelectronic device applications.

Systematic evaluation of the diagnostic approach of inflammatory bowel disease guidelines.

OBJECTIVE: To collect and evaluate the diagnostic approach of inflammatory bowel disease (IBD) guidelines and provide useful feedback for guideline developers and evidence-based clinical information to help physicians make decisions. METHODS: Diagnostic guidelines for IBD were retrieved by performing systemic and manual searches. Qualified clinical practice guidelines (CPGs) were included and then evaluated by four well-trained evaluators using the AGREE II instrument. To reduce the bias generated in this process, we used the Measurement Scale of Rate of Agreement (MSRA) tool to interpret the results. Guidelines with good recommendation distributions among the diagnostic field were further reclassified and evaluated. RESULTS: Fifteen diagnostic CPGs for IBD were identified and evaluated, and 70.3% (11/15) of the CPGs were above the recommended level. We observed heterogeneity among the diagnostic CPGs for IBD and discrepancies among different domains in one specific guideline. Potential improvements were identified in the fields of stakeholder involvement, rigour of development and applicability. By further analysing the heterogeneity of the recommendations and evidence in 5 UC-CPGs, we found the following issues: no discussion of diagnosing severe complications of UC, disputed significance of serologic and genetic diagnoses of UC, insufficient attention towards medical histories/physical examinations/differential diagnoses and discrepancy in classification criteria. CONCLUSION: The included diagnostic CPGs for IBD were generally of good quality, but heterogeneity was identified. Addressing these issues will provide useful feedback for the guideline updating process, and it will also benefit current clinical practice and eventually patient outcome.

Appraisal of the diagnostic procedures of acute pancreatitis in the guidelines.

OBJECTIVES: The purpose of this study was to comprehensively assess the heterogeneity of procedures in the diagnostic guidelines for acute pancreatitis and to identify gaps limiting knowledge in diagnosing this disease. METHODS: A systematic search of a number of databases was performed to determine the guidelines for the diagnosis of acute pancreatitis in patients with severe pancreatitis. The guidelines for the diagnosis of severe pancreatitis were evaluated by AGREE II. The Measurement Scale of Rate of Agreement (MSRA) was used to assess the guidelines (2015-2020) and extract evidence supporting these recommendations for analysis. RESULTS: Seven diagnostic guidelines for acute pancreatitis were included. Only the 2019 WSES Guidelines for the Management of Severe Acute Pancreatitis and the Japanese Guidelines for the Management of Acute Pancreatitis: Japanese Guidelines 2015 had a total score of more than 60%, which is worthy of clinical recommendation. The average scores of the Scope and Purpose domain and the Clarity and Expression domain were the highest at 71.62% and 75.59%, respectively, while the average score of the Applicability area was the lowest at 16.67%. The included guidelines were further analyzed to determine the heterogeneity of the diagnosis of acute pancreatitis. The main reasons for the heterogeneity were the citation of low-quality evidence, the presence of far too many indicators for the classification of acute pancreatitis, unclear depictions of the standard, and poorly comprehensive recommendations for the diagnosis of the aetiology in the primary diagnosis of acute pancreatitis, the severity classification, the aetiological diagnosis, and the diagnosis of comorbidities. CONCLUSIONS: The quality of different diagnostic guidelines for severe pancreatitis is uneven. The recommendations are largely based on low-quality evidence, and the guidelines still have much room for improvement to reach a high level of quality. The diagnostic procedures for acute pancreatitis vary widely in different guidelines. There are large differences between them, and resolving the abovementioned reasons would be a very wise choice for guideline developers to revise and upgrade the guidelines in the future.

Laser-Induced Interfacial Spallation for Controllable and Versatile Delamination of Flexible Electronics.

The control of interface status is greatly critical to release large-area, ultrathin flexible electronics from the donor wafer to achieve mechanical flexibility. This paper discovers a laser-induced interfacial spallation process for controllable and versatile delamination of polyimide (PI) films from transparent substrates and makes a comprehensive mechanism study of the controllability of interfacial delamination after laser irradiations. Microscopic observations show that backside irradiations will result in the formation of nanocavities around the PI-glass interface, enabling a significant decrease in interface adhesion. Theoretical calculations indicate that gas products generated from thermal decomposition of PI will cause hydrodynamic spallation of molten PI around the interface. The controllable spallation behavior benefits the formation/elimination of fibrous microconnections between the PI film and glass substrate. A substantial regulation of interfacial micromorphologies can achieve precise control of interface adhesion, mass production of functional nanostructures, and nondestructive peeling of ultrathin flexible devices. The results could be useful for the fabrication of flexible electronics and biomimetic surfaces.

Evaluation of guidelines for the management of perianal fistulas in Crohn's disease.

INTRODUCTION: The occurrence of perineal fistula is a significant evesnt in the evolution of Crohn's disease. Approximately 21% to 23% of patients develop perineal fistula at least once in their lifetime, approximately 30% of patients have cases of recurrence, and the refractory and recurrent perineal lesions of Crohn's disease impose a great economic burden on patients. The main purpose of this review was to investigate the quality of guidelines for perineal fistula in Crohn's disease. AREA COVERED: Relevant websites and databases were systematically searched to identify and select clinical guidelines related to perineal fistulas in Crohn's disease. Four independent reviewers assessed the eligible guidelines using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) and used intraclass correlation coefficients (ICC) to measure the agreement among the guideline reviewers. CONCLUSION: There is much room for improvement in the quality of guidelines for the management of perineal fistulas in Crohn's disease. The recommendations and evidence for guidelines for the management of perineal fistulas in Crohn's disease are quite heterogeneous, and guideline-developers would be well advised to address the above issues during future guideline development.

Heterogeneity of nutrition care procedures in nutrition guidelines for cancer patients.

OBJECTIVES: The aim of this study was to systematically assess the nutrition care procedures in nutrition guidelines for cancer patients and identify gaps limiting evidence-based practise. METHODS: A systematic search of databases and websites was conducted to identify nutrition guidelines for cancer patients. The quality of the eligible guidelines was evaluated by using the Appraisal of Guidelines for Research and Evaluation (AGREE II). The Measurement Scale of Rate of Agreement (MSRA) was used to assess the scientific agreement of formulated recommendations for nutrition care procedures in the guidelines (2017-2019), and evidence supporting these recommendations was extracted and analysed. RESULTS: Seventeen nutrition guidelines for cancer patients were identified. Only European Society for Clinical Nutrition and Metabolism (ESPEN) and Australian guidelines have a total quality score of more than 60%, which is worthy of clinical recommendation. Twelve guidelines (2017-2019) were included to further analyse the heterogeneity and causes of nutrition care procedures, and we found that the content and tools of nutrition screening and assessment, the application of immune nutrients, and the selection of nutritional support pathways were heterogeneous. The main reasons for the heterogeneity of nutrition care procedures were insufficient attention to nutrition risk screening, differences in recommendations for nutrition assessment, immune nutrients and nutritional support, unreasonable citation of screening and assessment evidence, preference of developers, and lack of evidence of high-quality research on energy and nitrogen demand. In addition, the fairness and propensity of the guidelines for the selection of evidence for different cancer patients are also potential reasons for the heterogeneity of nutritional care procedures. CONCLUSIONS: The quality of the nutrition guidelines for cancer patients was highly variable. The nutrition care procedures were heterogeneous among the different guidelines in the last 3 years. Specific improvement of the factors leading to the heterogeneity of nutrition care procedures will be a reasonable and effective way for developers to upgrade the nutrition care procedures in the guidelines for cancer patients.

Charged Satellite Drop Avoidance in Electrohydrodynamic Dripping.

The quality of electrohydrodynamic jet (e-jet) printing is crucially influenced by the satellite drop formed when the primary drop detaches from the meniscus. If the satellite drop falls onto the substrate, the patterns on the substrate will be contaminated. The electric charge carried by the satellite drop leads to more complex satellite/meniscus interaction than that in traditional inkjet printing. Here, we numerically study the formation and flight behavior of the charged satellite drop. This paper discovered that the charge relaxation time (CRT) of the liquid determines the electric repulsion force between the satellite drop and meniscus. The satellite drop will merge with the meniscus at long CRT, and fail to merge and deteriorate the printing quality at short CRT. The simulations are adopted to discover the mechanism of generation and flight behavior of charged satellite drops. The results show that the critical CRT decreases with the dielectric constant of the liquid and the supplied flow rate. Namely, for small dielectric constant and fixed CRT, the satellite drop is less likely to merge with the meniscus, and for high flow rate, the satellite drop is prone to merge with the meniscus due to the delay of necking thread breakup. These results will help to choose appropriate parameters to avoid the satellite drop from falling onto the substrate.

Experimental Study of the Influence of Ink Properties and Process Parameters on Ejection Volume in Electrohydrodynamic Jet Printing.

Electrohydrodynamic jet (e-jet) printing has very promising applications due to its high printing resolution and material compatibility. It is necessary to know how to choose the printing parameters to get the right ejection volume. The previous scaling law of the ejection volume in e-jet printing borrows the scaling law of the ejection volume of an unstable isolated droplet charged to the Rayleigh limit. The influence of viscosity, applied voltage amplitude, and nozzle-to-substrate distance on the ejection volume in e-jet printing was not taken into account in the scaling law. This study investigated the influence of viscosity, conductivity, applied voltage, and nozzle-to-substrate distance on the ejection volume. The ejection volume increases with viscosity and decreases with applied voltage and nozzle-to-substrate distance. The average electric field was kept unchanged while changing the nozzle-to-substrate distance by changing the applied voltage according to the electric field model of a semi-infinite wire perpendicular to an infinite large planar counter electrode. The ejection volume decreases with conductivity as V ~ K - 0.6 , which is different from the previous scaling law, which concludes that V ~ K - 1 . Finally, a model about the relation between the ejection volume and four parameters was established by regression analysis using a third-order polynomial. Two more experiments were done, and the predicted results of the fitted model accorded well with the experiments. The model can be used to choose the ink properties and process parameters to get the right ejection volume.

Large-Scale Direct-Writing of Aligned Nanofibers for Flexible Electronics.

Nanofibers/nanowires usually exhibit exceptionally low flexural rigidities and remarkable tolerance against mechanical bending, showing superior advantages in flexible electronics applications. Electrospinning is regarded as a powerful process for this 1D nanostructure; however, it can only be able to produce chaotic fibers that are incompatible with the well-patterned microstructures in flexible electronics. Electro-hydrodynamic (EHD) direct-writing technology enables large-scale deposition of highly aligned nanofibers in an additive, noncontact, real-time adjustment, and individual control manner on rigid or flexible, planar or curved substrates, making it rather attractive in the fabrication of flexible electronics. In this Review, the ground-breaking research progress in the field of EHD direct-writing technology is summarized, including a brief chronology of EHD direct-writing techniques, basic principles and alignment strategies, and applications in flexible electronics. Finally, future prospects are suggested to advance flexible electronics based on orderly arranged EHD direct-written fibers. This technology overcomes the limitations of the resolution of fabrication and viscosity of ink of conventional inkjet printing, and represents major advances in manufacturing of flexible electronics.

Flexible small-channel thin-film transistors by electrohydrodynamic lithography.

Small-channel organic thin-film transistors (OTFTs) are an essential component of microelectronic devices. With the advent of flexible electronics, the fabrication of OTFTs still faces numerous hurdles in the realization of highly-functional, devices of commercial value. Herein, a concise and efficient procedure is proposed for the fabrication of flexible, small-channel organic thin-film transistor (OTFT) arrays on large-area substrates that circumvents the use of photolithography. By employing a low-cost and high-resolution mechano-electrospinning technology, large-scale micro/nanofiber-based patterns can be digitally printed on flexible substrates (Si wafer or plastic), which can act as the channel mask of TFT instead of a photolithography reticle. The dimensions of the micro/nanochannel can be manipulated by tuning the processing parameters such as the nozzle-to-substrate distance, applied voltage, and fluid supply. The devices exhibit excellent electrical properties with high mobilities (∼0.62 cm2 V-1 s-1) and high on/off current ratios (∼2.47 × 106), and they are able to maintain stability upon being bent from 25 mm to 2.75 mm (bending radius) over 120 testing cycles. This electrohydrodynamic lithography-based approach is a digital, programmable, and reliable alternative for easily fabricating flexible, small-channel OTFTs, which can be integrated into flexible and wearable devices.

Buckling-driven self-assembly of self-similar inspired micro/nanofibers for ultra-stretchable electronics.

Self-similar structures are capable of highly enhancing the deformability of stretchable electronics. We presented a self-assembly method based on the tunable buckling of serpentine fiber-based interconnects (FiberBIs), which are deposited using our presented helix electrohydrodynamic printing (HE-printing) technique, to fabricate self-similar structures with enhanced stretchability (up to 250%). It provides a low-cost, printing-based approach for the generation of large-scale self-similar FiberBIs. Distinct buckling behaviors and modes occur under specific conditions. To elucidate the mechanics governing this phenomenon, we present detailed experimental and theoretical studies of the buckling mechanics of serpentine microfibers on compliant substrates. Firstly, the effect of the magnitude and direction of prestrain on the buckling behavior of a fiber-on-substrate is discussed. Secondly, the critical geometry of a serpentine fiber as a key parameter for fabricating uniform self-similar fibers is also figured out. Finally, the cross-sectional geometry of the fiber as a judgment criterion for determining the in-surface or out-of-surface buckling of the fiber is established. The investigation can guide the fabrication process of large-scale self-similar structures for high-performance electronic devices with extreme stretchability.