Large-area formation of self-aligned crystalline domains of organic semiconductors on transistor channels using CONNECT.

The electronic properties of solution-processable small-molecule organic semiconductors (OSCs) have rapidly improved in recent years, rendering them highly promising for various low-cost large-area electronic applications. However, practical applications of organic electronics require patterned and precisely registered OSC films within the transistor channel region with uniform electrical properties over a large area, a task that remains a significant challenge. Here, we present a technique termed "controlled OSC nucleation and extension for circuits" (CONNECT), which uses differential surface energy and solution shearing to simultaneously generate patterned and precisely registered OSC thin films within the channel region and with aligned crystalline domains, resulting in low device-to-device variability. We have fabricated transistor density as high as 840 dpi, with a yield of 99%. We have successfully built various logic gates and a 2-bit half-adder circuit, demonstrating the practical applicability of our technique for large-scale circuit fabrication.

Photoresponse Analysis of All-Inkjet-Printed Single-Walled Carbon Nanotube Thin-Film Transistors for Flexible Light-Insensitive Transparent Circuit Applications.

We report daylight-stable, transparent, and flexible single-walled carbon nanotube thin-film transistors (SWCNT TFTs) using an all-inkjet printing process. Although most of the previous reports classified SWCNT TFTs as photodetectors, we demonstrated that SWCNT films actually show two different types of photoresponses depending on the power levels of light sources. The electrical characteristics of SWCNT TFTs show no significant change under daily illumination conditions such as halogen lamps and sunlight, while under high-power laser illumination, they change as reported in the previous results. In addition, the low-temperature solution process of the SWCNT with its one-dimensional nature allows us to realize highly transparent and flexible TFTs and logic circuits on plastic substrates. Our result will provide new insights into utilizing SWCNT TFTs for light-insensitive transparent and flexible electronic applications.

A Case of Treated Penile Melanoma with Gastric Recurrence.

Melanoma is a very aggressive skin cancer that could metastasize to any organ in the body. The treatment of melanomas includes surgical resection, chemotherapy, and immunotherapy. After resections, melanomas could recur at the previous site or present as a distant metastatic lesion. The symptoms of melanoma are vague and primarily occur because of the local disruption of the tissue architecture. Presented here is a case of gastric melanoma that presented with abdominal discomfort and melena in a patient with a history of penile melanoma that was completely resected 3 years earlier. This case illustrates the importance of having metastatic lesions to the intestinal tract as a differential for a patient with gastrointestinal hemorrhage.

Spontaneous Resolution of IgG4-Related Hepatic Inflammatory Pseudotumor Mimicking Malignancy.

Hepatic inflammatory pseudotumor (IPT) is characterized by a well-circumscribed benign tumor mimicking or often mistaken for a malignant lesion. A 48-year-old male presented to the hospital with complaints of epigastric pain, with initial laboratory findings showing mildly elevated alkaline phosphatase (140 U/L) with normal AST, ALT, bilirubin, and lipase, a CD4 count of 384, and an HIV viral load of > 10 million copies. The total IgG level was elevated to 2,228 mg/dL (normal IgG4 level 114 mg/dL). Contrast-enhanced MRI of the abdomen showed heterogeneous mass-like infiltration in the right lobe of the liver measuring 9.6 cm. The liver mass was biopsied which showed dense collagenous fibrosis with abundant lymphoplasmacytic infiltrates with 18 IgG4-positive plasma cells per high-power field. The patient was not given any treatment for this IPT. For more than 1 year of follow-up triple-phase CT scan of the liver was repeated, which showed no liver mass. As radiological images of hepatic IPTs, including IgG4-related hepatic IPT, mimic liver malignancy, histological analysis of the biopsy remains the cornerstone for the diagnosis. Symptomatic patients with IgG4-related hepatic IPT have shown improvement with corticosteroid use; however, spontaneous resolution has also been reported like in the present case.

One-Step Interface Engineering for All-Inkjet-Printed, All-Organic Components in Transparent, Flexible Transistors and Inverters: Polymer Binding.

We report a one-step interface engineering methodology which can be used on both polymer electrodes and gate dielectric for all-inkjet-printed, flexible, transparent organic thin-film transistors (OTFTs) and inverters. Dimethylchlorosilane-terminated polystyrene (PS) was introduced as a surface modifier to cured poly(4-vinylphenol) dielectric and poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) electrodes without any pretreatment. On the untreated and PS interlayer-treated dielectric and electrode surfaces, 6,13-bis(triisopropylsilylethynyl)pentacene was printed to fabricate OTFTs and inverters. With the benefit of the PS interlayer, the electrical properties of the OTFTs on a flexible plastic substrate were significantly improved, as shown by a field-effect mobility (µFET) of 0.27 cm2 V-1 s-1 and an on/off current ratio (Ion/Ioff) of greater than 106. In contrast, the untreated systems showed a low µFET of less than 0.02 cm2 V-1 s-1 and Ion/Ioff ∼ 104. Additionally, the all-inkjet-printed inverters based on the PS-modified surfaces exhibited a voltage gain of 7.17 V V-1. The all-organic-based TFTs and inverters, including deformable and transparent PEDOT:PSS electrodes with a sheet resistance of 160-250 Ω sq-1, exhibited a light transmittance of higher than 70% (at wavelength of 550 nm). Specifically, there was no significant degradation in the electrical performance of the interface engineering-assisted system after 1000 bending cycles at a radius of 5 mm.

Transparent Large-Area MoS2 Phototransistors with Inkjet-Printed Components on Flexible Platforms.

Two-dimensional (2D) transition-metal dichalcogenides (TMDCs) have gained considerable attention as an emerging semiconductor due to their promising atomically thin film characteristics with good field-effect mobility and a tunable band gap energy. However, their electronic applications have been generally realized with conventional inorganic electrodes and dielectrics implemented using conventional photolithography or transferring processes that are not compatible with large-area and flexible device applications. To facilitate the advantages of 2D TMDCs in practical applications, strategies for realizing flexible and transparent 2D electronics using low-temperature, large-area, and low-cost processes should be developed. Motivated by this challenge, we report fully printed transparent chemical vapor deposition (CVD)-synthesized monolayer molybdenum disulfide (MoS2) phototransistor arrays on flexible polymer substrates. All the electronic components, including dielectric and electrodes, were directly deposited with mechanically tolerable organic materials by inkjet-printing technology onto transferred monolayer MoS2, and their annealing temperature of <180 °C allows the direct fabrication on commercial flexible substrates without additional assisted-structures. By integrating the soft organic components with ultrathin MoS2, the fully printed MoS2 phototransistors exhibit excellent transparency and mechanically stable operation.

Silver nanowire-embedded PDMS with a multiscale structure for a highly sensitive and robust flexible pressure sensor.

The development of highly sensitive pressure sensors with a low-cost and facile fabrication technique is desirable for electronic skins and wearable sensing devices. Here a low-cost and facile fabrication strategy to obtain multiscale-structured elastomeric electrodes and a highly sensitive and robust flexible pressure sensor is presented. The principles of spontaneous buckle formation of the PDMS surface and the embedding of silver nanowires are used to fabricate the multiscale-structured elastomeric electrode. By laminating the multiscale-structured elastomeric electrode onto the dielectric layer/bottom electrode template, the pressure sensor can be obtained. The pressure sensor is based on the capacitive sensing mechanism and shows high sensitivity (>3.8 kPa(-1)), fast response and relaxation time (<150 ms), high bending stability and high cycle stability. The fabrication process can be easily scaled up to produce pressure sensor arrays and they can detect the spatial distribution of the applied pressure. It is also demonstrated that the fingertip pressure sensing device can sense the pressure distribution of each finger, when grabbing an object.

Flexible high-performance all-inkjet-printed inverters: organo-compatible and stable interface engineering.

High-performance all-inkjet-printed organic inverters are fabricated on flexible substrates. By introducing end-functionalized polystyrene on both surfaces of inkjet-printed source/drain Ag electrodes and poly(4-vinylphenol) dielectrics, organic-compatible and hydroxyl-free interfaces between those layers and 6,13-bis(triisopropylsilylethynyl)pentacene drastically reduce the interfacial trap and contact resistance. The resulting organic inverters show a full up-down switching performance and a high voltage gain of 19.8.