Functionalized MXene ink enables environmentally stable printed electronics.

Establishing dependable, cost-effective electrical connections is vital for enhancing device performance and shrinking electronic circuits. MXenes, combining excellent electrical conductivity, high breakdown voltage, solution processability, and two-dimensional morphology, are promising candidates for contacts in microelectronics. However, their hydrophilic surfaces, which enable spontaneous environmental degradation and poor dispersion stability in organic solvents, have restricted certain electronic applications. Herein, electrohydrodynamic printing technique is used to fabricate fully solution-processed thin-film transistors with alkylated 3,4-dihydroxy-L-phenylalanine functionalized Ti3C2Tx (AD-MXene) as source, drain, and gate electrodes. The AD-MXene has excellent dispersion stability in ethanol, which is required for electrohydrodynamic printing, and maintains high electrical conductivity. It outperformed conventional vacuum-deposited Au and Al electrodes, providing thin-film transistors with good environmental stability due to its hydrophobicity. Further, thin-film transistors are integrated into logic gates and one-transistor-one-memory cells. This work, unveiling the ligand-functionalized MXenes' potential in printed electrical contacts, promotes environmentally robust MXene-based electronics (MXetronics).

Machine Learning-Based Development of Nomogram for Hepatocellular Carcinoma to Predict Acute Liver Function Deterioration After Drug-Eluting Beads Transarterial Chemoembolization.

RATIONALE AND OBJECTIVES: Acute liver function deterioration (ALFD) following drug-eluting beads transarterial chemotherapy embolism (DEB-TACE) was considered a risk factor for prognosis in patients with hepatocellular carcinoma (HCC). In this study, we aimed to develop and validate a nomogram for the prediction of ALFD after DEB-TACE. MATERIALS AND METHODS: A total of 288 patients with HCC from a single center were randomly divided into a training dataset (n = 201) and a validation dataset (n = 87). The univariate and multivariate logistic regression analyses were performed to determine risk factors for ALFD. The least absolute shrinkage and selection operator (LASSO) was applied to identify the key risk factors and fit a model. The performance, calibration, and clinical utility of the predictive nomogram were assessed using receiver operating characteristic curves, calibration curves, and decision curve analysis (DCA). RESULTS: LASSO regression analysis determined six risk factors with fibrosis index based on four factors (FIB-4) as the independent factor for the occurrence of ALFD after DEB-TACE. Gamma-glutamyltransferase, FIB-4, tumor extent, and portal vein invasion were integrated into the nomogram. In both the training and validation cohorts, the nomogram demonstrated promising discrimination with AUC of 0.762 and 0.878, respectively. The calibration curves and DCA revealed good calibration and clinical utility of the predictive nomogram. CONCLUSION: The nomogram-based risk of ALFD stratification may improve clinical decision-making and surveillance protocols for patients with a high risk of ALFD after DEB-TACE.

Amorphous Fluorinated Acrylate Polymer Dielectrics for Flexible Transistors and Logic Gates with High Operational Stability.

Fluorinated amorphous polymeric gate-insulating materials for organic thin-film transistors (OTFTs) not only form hydrophobic surfaces but also significantly reduce traps at the interface between the organic semiconductor and gate insulator. Therefore, these polymeric materials can enhance the OTFT's operation stability. In this study, we synthesized a new polymeric insulating material series composed of acrylate and fluorinated functional groups (with different ratios) named MBHCa-F and used them as gate insulators for OTFTs and in other applications. The insulating features of the MBHCa-F polymers, including surface energy, surface atomic content properties, dielectric constant, and leakage current, were clearly analyzed with respect to the content of the fluorinated functional groups. At higher fluorine-based functional group content, the polymeric series exhibited higher fluorine-based contents at the surface and superior electrical properties, such as field-effect mobility and driving stability, at OTFTs. Therefore, we believe that this study provides a substantial method for synthesizing polymeric insulating materials to enhance the operational stability and electrical performance of OTFTs.

Electrohydrodynamic-Jet-Printed Phthalimide-Derived Conjugated Polymers for Organic Field-Effect Transistors and Logic Gates.

A π-conjugated polymer semiconductor, PBDTTTffPI, was synthesized for use as an organic semiconductor suitable for electrohydrodynamic (EHD) jet printing technology. Bulky alkylation of the polymer gave PBDTTTffPI good solubility in several organic solvents. EHD jet printing using PBDTTTffPI ink produced direct patterns of polymer semiconductors while maintaining smooth surface morphologies and crystal structures similar to those of spin-coated PBDTTTffPI films. EHD-jet-printed PBDTTTffPI was appropriate for use as a semiconductor layer in organic field-effect transistors (OFETs) and logic gates. OFETs that used EHD-jet-printed PBDTTTffPI had better electrical characteristics than devices that used spin-coated semiconductor films. When a dielectric material (Al2O3) with a high dielectric constant was introduced, the jet-printed PBDTTTffPI operated well at low voltages. Integrated devices such as inverters, NAND gates, and NOR gates were fabricated by printing PBDTTTffPI patterns and showed good switching behaviors. Therefore, the use of printable PBDTTTffPI provides an advance toward fabrication of practical integrated arrays in next-generation devices.

Mass-Synthesized Solution-Processable Polyimide Gate Dielectrics for Electrically Stable Operating OFETs and Integrated Circuits.

Polyimides (PIs) are widely utilized polymeric materials for high-temperature plastics, adhesives, dielectrics, nonlinear optical materials, flexible hard-coating films, and substrates for flexible electronics. PIs can be facilely mass-produced through factory methods, so the industrial application value is limitless. Herein, we synthesized a typical poly(amic acid) (PAA) precursor-based solution through an industrialized reactor for mass production and applied the prepared solution to form thin films of PI using thermal imidization. The deposited PI thin films were successfully applied as gate dielectrics for organic field-effect transistors (OFETs). The PI layers showed suitable characteristics for dielectrics, such as a smooth surface, low leakage current density, uniform dielectric constant (k) values regardless of frequency, and compatibility with organic semiconductors. Utilizing this PI layer, we were able to fabricate electrically stable operated OFETs, which exhibited a threshold voltage shift lower than 1 V under bias-stress conditions and a field-effect mobility of 4.29 cm2 V-1 s-1. Moreover, integrated logic gates were manufactured using these well-operated OFETs and displayed suitable operation behavior.

Direct Patterned Zinc-Tin-Oxide for Solution-Processed Thin-Film Transistors and Complementary Inverter through Electrohydrodynamic Jet Printing.

The solution-processed deposition of metal-oxide semiconducting materials enables the fabrication of large-area and low-cost electronic devices by using printing technologies. Additionally, the simple patterning process of these types of materials become an important issue, as it can simplify the cost and process of fabricating electronics such as thin-film transistors (TFTs). In this study, using the electrohydrodynamic (EHD) jet printing technique, we fabricated directly patterned zinc-tin-oxide (ZTO) semiconductors as the active layers of TFTs. The straight lines of ZTO semiconductors were successfully drawn using a highly soluble and homogeneous solution that comprises zinc acrylate and tin-chloride precursors. Besides, we found the optimum condition for the fabrication of ZTO oxide layers by analyzing the thermal effect in processing. Using the optimized condition, the resulting devices exhibited satisfactory TFT characteristics with conventional electrodes and conducting materials. Furthermore, these metal-oxide TFTs were successfully applied to complementary inverter with conventional p-type organic semiconductor-based TFT, showing high quality of voltage transfer characteristics. Thus, these printed ZTO TFT results demonstrated that solution processable metal-oxide transistors are promising for the realization of a more sustainable and printable next-generation industrial technology.

Direct Printing of Asymmetric Electrodes for Improving Charge Injection/Extraction in Organic Electronics.

Engineering the energy levels of organic conducting materials can be useful for developing high-performance organic field-effect transistors (OFETs), whose electrodes must be well controlled to facilitate easy charge carrier transport from the source to drain through an active channel. However, symmetric source and drain electrodes that have the same energy levels are inevitably unfavorable for either charge injection or charge extraction. In this study, asymmetric source and drain electrodes are simply prepared using the electrohydrodynamic (EHD)-jet printing technique after the careful work function engineering of organic conducting material composites. Two types of additives effectively tune the energy levels of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate-based composites. These solutions are alternately patterned using the EHD-jet printing process, where the use of an electric field makes fine jet control that enables to directly print asymmetric electrodes. The asymmetric combination of EHD-printed electrodes helps in obtaining advanced charge transport properties in p-type and n-type OFETs, as well as their organic complementary inverters. This strategy is believed to provide useful guidelines for the facile patterning of asymmetric electrodes, enabling the desirable properties of charge injection and extraction to be achieved in organic electronic devices.

Enhanced solvent resistance and electrical performance of electrohydrodynamic jet printed PEDOT:PSS composite patterns: effects of hardeners on the performance of organic thin-film transistors.

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) is of great interest as a promising metal-free electrode material for future electronic devices. Several printing techniques have been developed to generate PEDOT:PSS patterns. In this study, we introduced a silicon-based hardener into PEDOT:PSS composites to prepare conductive ink for the purpose of fabricating solvent-resistant PEDOT:PSS composite patterns. Electrohydrodynamic (EHD) jet printing enabled the direct patterning of PEDOT:PSS and hardener composites that exhibited improved electrical conductivity and solvent resistance, which are advantageous properties for efficient charge injection when semiconductor materials are coated onto pre-deposited PEDOT:PSS composite electrodes. By using EHD jet printed PEDOT:PSS composites as source and drain electrodes, bottom-gate-bottom-contact organic thin-film transistors (OTFTs) were fabricated. The resulting OTFTs with PEDOT:PSS and hardener composite electrodes exhibited superior electrical performance compared to OTFTs with electrodes without hardener. Finally, OTFTs with both EHD jet printed electrodes and semiconductors were fabricated and analyzed.