Nanomaterial integration in micro LED technology: Enhancing efficiency and applications

The micro-light emitting diode (µLED) technology is poised to revolutionise display applications through the introduction of nanomaterials and Group III-nitride nanostructures. This review charts state-of-the-art in this important area of micro-LEDs by highlighting their key roles, progress and concerns. The review encompasses details from various types of nanomaterials to the complexity of gallium nitride (GaN) and III nitride nanostructures. The necessity to integrate nanomaterials with III-nitride structures to create effective displays that could disrupt industries was emphasised in this review. Commercialisation challenges and the economic enhancement of micro-LED integration into display applications using monolithic integrated devices have also been discussed. Furthermore, different approaches in micro-LED development are discussed from top-down and bottom-up approaches. The last part of the review focuses on nanomaterials employed in the production of micro-LED displays. It also highlights the combination of III-V LEDs with silicon LCDs and perovskite-based micro-LED displays. There is evidence that efficiency and performance have improved significantly since the inception of the use of nanomaterials in manufacturing these

5 European & African Conference on Wind Engineering

The 5th European-African Conference of Wind Engineering is hosted in Florence, Tuscany, the city and the region where, in the early 15th century, pioneers moved the first steps, laying down the foundation stones of Mechanics and Applied Sciences (including fluid mechanics). These origins are well reflected by the astonishing visionary and revolutionary studies of Leonardo Da Vinci, whose kaleidoscopic genius intended the human being to become able to fly even 500 years ago… This is why the Organising Committee has decided to pay tribute to such a Genius by choosing Leonardo's "flying sphere" as the brand of 5th EACWE

Creation and Application of Routines for Determining Physical Properties of Asteroids and Exoplanets from Low Signal-To-Noise Data Sets

Astronomy is a data heavy field driven by observations of remote sources reflecting or emitting light. These signals are transient in nature, which makes it very important to fully utilize every observation. This however is often difficult due to the faintness of these observations, often are only slightly above the level of observational noise. We present new or adapted methodologies for dealing with these low signal-to-noise scenarios, along with practical examples including determining exoplanet physical properties, periodicities in asteroids, and the rotational and orbital properties of the multiple asteroid system 2577 Litva

ICR ANNUAL REPORT 2020 (Volume 27)[All Pages]

This Annual Report covers from 1 January to 31 December 202

Cavitation-enhanced permeability in a vessel on a chip

Methods combining ultrasound and microbubbles (USMB) offer the unique capability of non-invasively, locally and transiently increase endothelial permeability [1]. This is crucial for the delivery of pharmaceutical agents, injected into the blood circulation, since the real efficiency of a therapy depends on the rate and ability of a macromolecules to cross the endothelial barrier and reach the intended target. Molecule passage through this biological barrier is hampered by the endothelium, lining the innermost surface of blood vessels, consisting of a continuum layer of specialized cells close together to form a size-selective membrane. In this contest, cavitation-assisted permeation shows promise for reversibly altering the barrier integrity, opening gaps between endothelial cells and doing so facilitating the diffusion of pharmaceutical agents out of vessel. Although acoustic cavitation is already exploited in in vivo animal models for drug delivery testing, the in vitro approach offers the possibility to obtain well-controlled procedures, saving in cost and time [2]. Here, a platform integrating in vitro blood vessels and acoustic cavitation is used to test the feasibility of micro bubbles (MBs) cavitation-enhanced endothelial permeability. We induce MBs (Sonovue® contrast agent) stable cavitation, evoked by low-intensity ultrasound exposure (Mechanical Index (MI) = 0.4, 0.72), in a microfluidic device purposely designed [3] to mimic micro-blood vessel. The bio-inspired device consists in a PDMS microfluidic network with a central circular tissue compartment enclosed by two independent vascular channels mimicking the three-dimensional morphology, size and flow characteristics of a micro vessel in vivo. The device is previously cultured with Human Umbilical Vein Endothelial Cells (HUVECs) with a reliable and reproducible protocol [4] that allows endothelial cells to form a complete lumen under physiological shear stresses. Immunofluorescence microscopy is then exploited in order to monitor vascular integrity following vascular endothelial cadherin (VE-Cadherin), the most determinant protein for vascular permeability. The endothelial membrane permeability is evaluated through a dedicated optical/acoustic set-up in presence of ultrasound-activated MBs driven by 1 MHz-unfocused transducer. The basic set up is designed and adapted to host the bio-inspired device, the piezoelectric transducers within a water-filled and temperature-controlled costume chamber located on the microscope stage. Measurements of fluorescent dye diffusion towards the biological membrane has been carried out with a time lapse acquisition under a confocal microscope operated in epifluorescence mode. An image analysis on the intensity change due to fluorescence accumulation in the tissue compartment is performed to obtain quantification of permeability. Intercellular gaps were firstly identified by inspection using ImageJ software and then post-processed in order to increase the contrast and binarize the image using a threshold method with the same cut-off value for all Regions of Interest. The gap area was then quantified counting the black pixels of the central connected blob in each binarized image. The results show that MBs amplify the ultrasound effect, leading to the formation of inter-endothelial gaps, proportionally to the applied acoustic pressure, and causing barrier permeabilization. Moreover, endothelium recovery was completely achieved after 45 minutes from the USMB exposure with gap area distribution returning to the control levels. To conclude, the proposed integrated platform allows for precise and repeatable in vitro measurements of cavitation-enhanced endothelium permeability providing a novel methodology for the quantitative understanding of cavitation assisted drug delivery. [1] K. Kooiman, H. J. Vos, M. Versluis, and N. de Jong, “Acoustic behaviour of microbubbles and implications for drug delivery,” Advanced drug delivery reviews, vol. 72, pp. 28–48, 2014. [2] Peruzzi, G. Perspective on cavitation enhanced endothelial layer permeabiliry, Colloids and surface B: biointerfaces 168 (2018), 3-93 [3] S.P.Deosarkar, et al. A novel dynamic neonatal blood-brain barrier on a chip, Plos One, 10(11) (2015), p. e014272

The Halogen Bond

The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design

ICR ANNUAL REPORT 2019 (Volume 26)[All Pages]

This Annual Report covers from 1 January to 31 December 201

Electron Emission and Transport Properties Database for Spacecraft Charging Models

Modeling the rate and likelihood of spacecraft charging during spacecraft mission is critical to determine mission length, proposed spacec­raft attitude, and spacecraft design. The focus of this work is the creation and utilization of a database of secondary electron yield (SEY) measurements for a host of materials to increase accuracy in spacecraft modeling. Traditional methods of SEY data selection for input into spacecraft charging codes typically include the use of compiled materials databases incorporated in charging codes or selecting values from a specific scientific study. The SEY database allows users to select data inputs based upon the details associated with the studies used to generate the data. Qualifications of data based upon surface morphology, surface contamination, and data origin are all included as well as a brief guide to assist researchers in understanding the way to best determine which dataset would best model their craft in its proposed environment. Such qualifications of data allow for more accurate modeling and for the amount of fault tree analysis utilized in spacecraft monitoring to be decreased as a more accurate root cause analysis can be performed preflight