Distortion-Free Stretchable Light-Emitting Diodes via Imperceptible Microwrinkles

Stretchable organic light-emitting diodes (OLEDs) have been considered as a promising technology for next-generation free-form and wearable displays. However, an approach to ensure both high device performance and high resolution has not yet been suggested. While introducing a wrinkled structure in the active pixel areas is a decent method, the formation of out-of-plane macroscopic wrinkles having a wavelength of a few hundred mu m has caused distortion in the shape of the pixel, which is a critical drawback for a matrix-configured display demanding a sharp pixel definition. Herein, microwrinkled OLEDs are fabricated to define a distortion-free pixel by direct deposition of OLEDs on biaxially prestretched elastomeric substrate, being feasible by a low-temperature-based solution process. The total thickness of the device can be significantly reduced up to 350 nm, producing the imperceptible microwrinkles having a wavelength under 20 mu m. The microwrinkled OLEDs show a luminance over 8000 cd m(-2) and maximum current efficiency of 7.76 cd A(-1), which is comparable to the device without wrinkled structure. Finally, a stretchable 4 x 4 OLED pixel array with a microwrinkled structure is demonstrated showing sharply defined square-patterned emission, proving the potential in the future high-resolution stretchable display.N

A 6.4Gbps On-Chip Eye Opening Monitor Circuit for Signal Integrity Analysis of High Speed Channel

In this paper, an on-chip eye opening monitor circuit has been proposed with 4ps time and 4mv voltage resolutions for analyzing signal integrity of on-chip high speed channel. The proposed eye opening monitor circuit can detect the maximum 6.4Gbps data rate and give eye diagrams depending on on-chip high speed channel conditions. The performance of the proposed eye opening monitor circuit was verified by using a general spice simulations and showed the variations of eye diagram of 6.4 Gbps random data when on-die terminations of on-chip high speed channel was changed from 50 ohm to 80 ohm

Advancements in Electronic Materials and Devices for Stretchable Displays

A stretchable display would be the ultimate form factor for the next generation of displays beyond the curved and foldable configurations that have enabled the commercialization of deformable electronic applications. However, because conventional active devices are very brittle and vulnerable to mechanical deformation, appropriate strategies must be developed from the material and structural points of view to achieve the desired mechanical stretchability without compromising electrical properties. In this regard, remarkable findings and achievements in stretchable active materials, geometrical designs, and integration enabling technologies for various types of stretchable electronic elements have been actively reported. This review covers the recent developments in advanced materials and feasible strategies for the realization of stretchable electronic devices for stretchable displays. In particular, representative strain-engineering technologies for stretchable substrates, electrodes, and active devices are introduced. Various state-of-the-art stretchable active devices such as thin-film transistors and electroluminescent devices that consist of stretchable matrix displays are also presented. Finally, the future perspectives and challenges for stretchable active displays are discussed.N

Photovoltaic powered solar hydrogen production coupled with waste SO2 valorization enabled by MoP electrocatalysts

In this study, we demonstrated high-rate H2 generation by coupling with the sulfite oxidation reaction (SOR) as an alternative to the oxygen evolution reaction for solar H2 production. The emerging and cost-effective molybdenum phosphide electrocatalyst was appropriately optimized and used as a bifunctional catalyst in an alkaline electrolyte for both SOR and HER. Powered by state-of-the-art perovskite–Si tandem photovoltaics, a remarkable photocurrent density of over 17 mA cm−2 was achieved in the HER coupled with the SOR. In addition to the significantly enhanced photocurrent, the SOR can further reduce the overall cost of solar H2 production owing to the elimination of the expensive membranes required for H2 and O2 gas separation. Considering the high global demand for desulfurization via the SOR, the strategy proposed here will enable practical H2 production from renewable sources while effectively converting the toxic SO2 gas into a value-added product for the chemical industry

Visualization 2

Visualization 2 shows seamless display using cylindrical lens pair for actual image with different viewing direction

Ultraflexible and transparent electroluminescent skin for real-time and super-resolution imaging of pressure distribution

The ability to image pressure distribution over complex three-dimensional surfaces would significantly augment the potential applications of electronic skin. However, existing methods show poor spatial and temporal fidelity due to their limited pixel density, low sensitivity, or low conformability. Here, we report an ultraflexible and transparent electroluminescent skin that autonomously displays super-resolution images of pressure distribution in real time. The device comprises a transparent pressure-sensing film with a solution-processable cellulose/nanowire nanohybrid network featuring ultrahigh sensor sensitivity (>5000 kPa(-1)) and a fast response time (<1 ms), and a quantum dot-based electroluminescent film. The two ultrathin films conform to each contact object and transduce spatial pressure into conductivity distribution in a continuous domain, resulting in super-resolution (>1000 dpi) pressure imaging without the need for pixel structures. Our approach provides a new framework for visualizing accurate stimulus distribution with potential applications in skin prosthesis, robotics, and advanced human-machine interfaces. Electronic skin that spatially maps pressure distribution through imaging shows limited performance despite improvements to data acquisition. Here, the authors report ultraflexible, transparent electroluminescent skin capable of high-resolution imaging of pressure distribution over 3D surfaces.Y

Nur77 upregulates HIF-α by inhibiting pVHL-mediated degradation

In this study, we investigated the role of Nur77, an orphan nuclear receptor, in HIF-α transcriptional activity. We found that Nur77 associates and stabilizes HIF-1α via indirect interaction. Nur77 was found to interact with pVHL in vivo via the α-domain of pVHL. By binding to pVHL, Nur77 competed with elongin C for pVHL binding. Moreover, Nur77-binding to pVHL inhibited the pVHL-mediated ubiquitination of HIF-1α and ultimately increased the stability and transcriptional activity of HIF-1α. The ligand-binding domain of Nur77 was found to interact with pVHL and the expression of this ligand-binding domain was sufficient to stabilize and transactivate HIF-1α. Under the conditions that cobalt chloride was treated or pVHL was knocked down, Nur77 could not stabilize HIF-α. Moreover, Nur77 could not further stabilize HIF-2α in A498/VHL stable cells, which is consistent with our finding that Nur77 indirectly stabilizes HIF-α by binding to pVHL. Thus, our results suggest that an orphan nuclear receptor Nur77 binds to pVHL, thereby stabilizes and increases HIF-α transcriptional activity under the non-hypoxic conditions