Search

Encapsulating materials for light‐emitting diodes (LEDs) with optical‐grade polymeric resin is essential to protect from external environments and to improve light‐extraction efficiency (LEE) in micro‐scale LED (µ‐LED). In addition, the formation of microlens can further enhance the optical performance of µ‐LED. However, previously developed materials have limitations due to a lack of rheological properties and thermal stability. Here, the fabrication of sol–gel derived phenyl siloxane hybrid (PSH) that has a high refractive index (n), for use as an encapsulating material for µ‐LEDs is reported. Fumed silica nanoparticles (FSNs) are mixed with the PSH to yield siloxane/silica nanocomposites that have thixotropic properties, which enable the formation of microlens arrays. Optimizing the concentration of FSN in the nanocomposites yields a siloxane/silica nanocomposite that has a high n = 1.590 at 486 nm, high thixotropic index = 3.956, and increased optical haze (79.83% at 550 nm) makes light scattering. The use of PSH significantly increases the LEE of the LED (124.6% increase compared to an LED that does not use it). Finally, the siloxane/silica nanocomposite is used to direct‐dispense microlenses on µ‐LEDs in arrays. The encapsulation strategy can increase both the LEE and reliability of µ‐LEDs. [ABSTRACT FROM AUTHOR]

This study conducted a rapid review to evaluate active air sampling and analytical methods for characterizing outdoor air microplastics in urban areas. We synthesized information from 35 peer-reviewed journal articles. Studies utilizing active sampling methods were able to provide detailed data on inhalation concentrations and doses. The analytical techniques reviewed were categorized into microscopy, Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and mass spectrometry, including pyrolysis–gas chromatography (Py-GC). While conventional FTIR and Raman spectroscopy can identify microplastics in total suspended particles, advanced instruments such as µRaman and SEM are crucial for analyzing inhalable microplastics (e.g., particles smaller than 10 µm). Characterizing the shapes and colours of microplastics can provide qualitative estimates of their sources, with fibres and the colour black being the most predominant characteristics. Establishing dose–response relationships for health effects requires quantitative analyses; thus, combining techniques like µRaman with Py-GC is essential for comprehensive human risk assessments. Future studies should focus on identifying and quantifying inhalable microplastic compounds that are relevant to human health. [ABSTRACT FROM AUTHOR]

Over the past few years, earth-abundant transition metal-catalyzed hydrosilylation has emerged as an ideal strategy for the synthesis of organosilanes. The success in this area of research has expanded to the advancements of alkyne dihydrosilylation reactions, offering broadened synthetic applications through the selective installation of two silyl groups. In particular, catalysts based on Fe, Co, and Ni have engendered enabling platforms for mild transformations with a range of distinct regioselectivity. This mini-review summarizes recent advances in this research field, highlighting the unique features of each system from both synthetic and mechanistic perspectives. [ABSTRACT FROM AUTHOR]

In this study, we introduce the world's first development of a full‐color micro‐LED display utilizing a Simultaneous Transfer and Bonding (SITRAB) process and a novel SITRAB film. Developed micro‐LED display involves R/G/B micro‐LED chips measuring 35 × 20 µm 2, arranged into a display resolution of 32 × 32, with a pixel pitch of 324 µm and a subpixel pitch of 50 µm. The micro‐LED display utilizes a glass substrate and aluminum wiring. A key innovation in our process is the use of indium solder for low‐temperature bonding, significantly enhancing the assembly process's efficiency and reliability. The SITRAB film, a specially developed material by ourselves, removes the surface oxide of indium solders, facilitating effective bonding between the micro‐LEDs and the display electrodes. Post‐curing of this SITRAB film further enhances the shear strength of the micro‐LEDs. An average shear strength of approximately 5.45 gf (about 32 MPa), significantly surpassing the tensile strength of indium. These advancements not only demonstrate the feasibility of the SITRAB process and the new film material in creating high‐quality micro‐LED displays but also significantly boost the reliability of these displays. [ABSTRACT FROM AUTHOR]

Micro light‐emitting diodes (µLEDs) have been considered as next‐generation display technologies, but they suffer from low productivity due to poor heat dissipation, high electrical resistance, and repair difficulty of conventional µLED bonding methods. Simultaneous transfer and bonding (SITRAB) technology enables electrically/thermally conductive soldering for high‐resolution µLED displays. In this study, the transfer, bonding, and repair of InGaN/GaN µLEDs via the SITRAB method are reported. µLEDs grown on sapphire substrates are assembled on a backplane via the SITRAB process. The SITRAB‐based repair of defective pixels is demonstrated by transferring redundant LEDs to the display substrates. [ABSTRACT FROM AUTHOR]

Wireless modules that provide telecommunications and power-harvesting capabilities enabled by radio-frequency (RF) electronics are vital components of skin-interfaced stretchable electronics1–7. However, recent studies on stretchable RF components have demonstrated that substantial changes in electrical properties, such as a shift in the antenna resonance frequency, occur even under relatively low elastic strains8–15. Such changes lead directly to greatly reduced wireless signal strength or power-transfer efficiency in stretchable systems, particularly in physically dynamic environments such as the surface of the skin. Here we present strain-invariant stretchable RF electronics capable of completely maintaining the original RF properties under various elastic strains using a ‘dielectro-elastic’ material as the substrate. Dielectro-elastic materials have physically tunable dielectric properties that effectively avert frequency shifts arising in interfacing RF electronics. Compared with conventional stretchable substrate materials, our material has superior electrical, mechanical and thermal properties that are suitable for high-performance stretchable RF electronics. In this paper, we describe the materials, fabrication and design strategies that serve as the foundation for enabling the strain-invariant behaviour of key RF components based on experimental and computational studies. Finally, we present a set of skin-interfaced wireless healthcare monitors based on strain-invariant stretchable RF electronics with a wireless operational distance of up to 30 m under strain.Stretchable radio-frequency electronics based on a dielectro-elastic elastomer is demonstrated to be capable of completely maintaining operating frequencies unaffected by strain and shows superior electrical, mechanical and thermal properties compared with conventional stretchable substrate materials. [ABSTRACT FROM AUTHOR]

In this study, we present the development of a highly reliable 64 × 64 Mini‐LED display, where the LED array is transferred/bonded onto a glass substrate using SITRAB technology and materials. The display substrate was fabricated by patterning two layers of Cu on top of heat‐resistant glass with a thickness of 500 μm. We applied SITRAB solder paste containing type 6 solder powder based on a resin matrix to the display substrate using screen printing. Subsequently, we transferred and bonded the 64 × 64 color LED array using the SITRAB process. The pixel pitch is 450 μm, corresponding to a 78" 4K display. No bad pixels were found among a total of 12288 LEDs. We analyzed the shear strength and reliability test results of LED chips bonded using SITRAB materials and processes. By applying SITRAB materials, the shear strength of the LED chips was increased by 27% before and 45% after reliability testing compared to the chips without added resin. [ABSTRACT FROM AUTHOR]

We used simultaneous transfer and bonding (SITRAB) technology to fabricate a full‐color Mini‐LED display on a flexible substrate. SITRAB technology is ETRI's patented technology that integrates transfer and bonding into a single process. We adopted a 25 μm‐thick polyimide film as the display substrate. RIGIB Mini‐LEDs were arrayed on a glass carrier as a 32 × 32 array. RIGS Mini‐LEDs on twelve glass carriers were transfer‐bonded to the display substrate through a tiling process. The fabricated display consists of 64 × 64 color pixels, which are connected in a passive matrix [ABSTRACT FROM AUTHOR]

We developed a simultaneous transfer and bonding (SITRAB) process based on laser‐assisted bonding with compression (LABC) and our proprietary SITRAB adhesive technology. As its name implies, the SITRAB process performs transfer and bonding simultaneously, unlike the conventional sequential process, in which transfer is followed by the bonding process. SITRAB's process time is less than 6 s. The SITRAB adhesive was developed in the form of a paste and a film, and an appropriate type of adhesive can be applied depending on the applications. The adhesive was proved to be applied as SnAg and In solders during the SITRAB process. Two 35 × 35 arrays of 80 µm × 130 µm sized mini LEDs with a 288 µm pitch with SnAg or In interconnects have been successfully processed. The repair process based on SITRAB technology was proposed and confirmed experimentally. [ABSTRACT FROM AUTHOR]

Metformin, a potent AMPK activator is the most commonly used drug for diabetes. According to recent reports, metformin lowers the risk of diabetic complications and inflammatory diseases. We found the expression levels of AMPK subunits including PRKAA1, PRKAA2, PRKAB1 and PRKAB2 are decreased in skin biopsies of dermatitis patients from multiple datasets. Interestingly, metformin treatment ameliorates dermatitis symptom in animal model of dermatitis using O-tetradecanoylphorbol-13-acetate (TPA). Especially, the levels of epidermis and dermis thickness were decreased by metformin. We found NFκB activity as well as of gene expression associated with collagen synthesis are attenuated by metformin treatment. These results suggest that metformin treatment alleviates animal model of dermatitis. [ABSTRACT FROM AUTHOR]

Nintedanib, a receptor tyrosine kinase (RTK) inhibitor has been developed as therapeutics for idiopathic pulmonary fibrosis and non-small lung cancer. We found that the expression levels of RTK, especially VEGFR1 is increased in skin biopsies of dermatitis patients from multiple independent datasets. Moreover, VEGFR1 is highly expressed by infiltrated cells in dermis from oxazolone (OXA) treated mice. Interestingly, nintedanib alleviates dermatitis symptom in OXA-induced animal model. Especially, levels of epidermis thickness, infiltrated immune cells including mast cells and eosinophils were decreased from mice cotreated with nintedanib and OXA compared with OXA treated mice. Moreover, serum IgE and Th2 cytokines including IL-4 and IL-13 were decreased by nintedanib treatment. These results suggest an evidence that nintedanib alleviates animal model of dermatitis. [ABSTRACT FROM AUTHOR]

Traditional technologies for virtual reality (VR) and augmented reality (AR) create human experiences through visual and auditory stimuli that replicate sensations associated with the physical world. The most widespread VR and AR systems use head-mounted displays, accelerometers and loudspeakers as the basis for three-dimensional, computer-generated environments that can exist in isolation or as overlays on actual scenery. In comparison to the eyes and the ears, the skin is a relatively underexplored sensory interface for VR and AR technology that could, nevertheless, greatly enhance experiences at a qualitative level, with direct relevance in areas such as communications, entertainment and medicine1,2. Here we present a wireless, battery-free platform of electronic systems and haptic (that is, touch-based) interfaces capable of softly laminating onto the curved surfaces of the skin to communicate information via spatio-temporally programmable patterns of localized mechanical vibrations. We describe the materials, device structures, power delivery strategies and communication schemes that serve as the foundations for such platforms. The resulting technology creates many opportunities for use where the skin provides an electronically programmable communication and sensory input channel to the body, as demonstrated through applications in social media and personal engagement, prosthetic control and feedback, and gaming and entertainment. Interfaces for epidermal virtual reality technology are demonstrated that can communicate by programmable patterns of localized mechanical vibrations. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) derived from bone marrow, adipose tissue, and most connective tissues have been recognized as promising sources for cell-based therapies. MSCs have also been detected in human pancreatic tissue, including endocrine and exocrine cells. These adult human pancreas-derived MSCs have generated a great deal of interest owing to their potential use in the differentiation of insulin-producing cells for diabetes treatment. In the present study, we isolated MSCs from the adult human exocrine pancreas to determine whether isolated MSCs have the potential to differentiate into pancreatic endocrine cells and, therefore, whether they can be used in stem cell-based therapies. Pancreatic tissue was digested by collagenase and an enriched exocrine-cell fraction was obtained by density-gradient separation. Crude exocrine cells were methodically cultured in suspension and then in adherent culture. We expanded the human pancreatic exocrine-derived MSCs (hpMSCs) by cell passaging in culture and confirmed by flow cytometry that >90% expressed human classic surface markers of MSCs. Interestingly, these cells expressed pancreatic transcription factors, such as Pdx1, Ngn3, and MafA, similar to pancreatic progenitor cells. These results indicated that hpMSCs can be used for the differentiation of pancreatic endocrine cells and may be used in type 1 diabetes treatment. [ABSTRACT FROM AUTHOR]

An epoxy-based solder paste (ESP) is a promising alternative to conventional solder pastes to improve the reliability of fine-pitch electrical joining because the epoxy encapsulates the solder joint. However, development of an appropriate epoxy formulation and investigation of its reaction mechanism with solder powder is challenging. In this study, we demonstrate a newly designed ESP consisting of diglycidyl ether of bisphenol F (DGEBF) resin, Sn-3.0 Ag-0.5 Cu (SAC305) solder powder, and L-glutamic acid (Glu), which is a proteinogenic amino acid for biosynthesis of proteins in living systems. The mechanism of the thermochemical reaction was explored and tentatively proposed, which reveals that the products of the reaction between SAC305 and Glu function as catalysts for the etherification of epoxides and alcohols produced by chemical bonding between DGEBF and Glu, consequently leading to highly crosslinked polymeric networks and an enhancement of impact resistance. Our findings provide further insight into the mechanism of the reaction between various formulations comprising an epoxy, amino acid, and solder powder, and their potential use as ESPs for electrical joining. [ABSTRACT FROM AUTHOR]

Developing dermatitis therapeutics has been faced with challenges including adverse effects of topical steroid and high cost of new developing drugs. Here, we found the expression levels of dopamine receptor D2 is higher in skin biopsies of dermatitis patients and an oxazolone-induced animal model of dermatitis. We used perphenazine, an FDA-approved dopamine receptor antagonist to determine the therapeutic effect. Two different animal models including 12-o-tetradecanoylphorbol-13-acetate (TPA) and oxazolone (OXA)-induced dermatitis were employed. TPA and OXA-mediated ear swelling was attenuated by perphenazine. Moreover, perphenazine inhibited infiltrated mast cells into lesion area. We found levels of serum IgE, histamine and cytokines are decreased in mice cotreated with perphenazine and OXA compared to OXA-treated mice. Overall, this is a first study showing that the FDA-approved, anti-psychotic drug, perphenazine, alleviates animal models of dermatitis. [ABSTRACT FROM AUTHOR]

Glucose metabolism is a key metabolic pathway that orchestrates cellular homeostasis by generating ATP, nucleotides, and amino acids. Abnormal glucose signaling has been found in many diseases including cancers and inflammatory diseases. According to recent report, glycolysis contributes to pathogenesis of psoriasis and ablation of Glut1 attenuates animal models of psoriasis. While we were screening a molecular target for atopic dermatitis, we found the levels of glucose transporters including Glut1 (SLC2a1) and Glut3 (SLC2a3) are highly expressed in skin biopsies of dermatitis patients from multiple datasets. We demonstrated that administration of 2-deoxy-d-glucose (2DG) ameliorates animal models of 12-o-tetradecanoylphorbol-13-acetate (TPA) and oxazolone induced dermatitis using morphological and histological analysis. These results suggest that inhibition of glucose metabolism ameliorates dermatitis in animal models. [ABSTRACT FROM AUTHOR]