High-Yield Large-Scale Suspended Graphene Membranes over Closed Cavities for Sensor Applications.

Suspended membranes of monatomic graphene exhibit great potential for applications in electronic and nanoelectromechanical devices. In this work, a "hot and dry" transfer process is demonstrated to address the fabrication and patterning challenges of large-area graphene membranes on top of closed, sealed cavities. Here, "hot" refers to the use of high temperature during transfer, promoting the adhesion.

Button shear testing for adhesion measurements of 2D materials.

Two-dimensional (2D) materials are considered for numerous applications in microelectronics, although several challenges remain when integrating them into functional devices. Weak adhesion is one of them, caused by their chemical inertness. Quantifying the adhesion of 2D materials on three-dimensional surfaces is, therefore, an essential step toward reliable 2D device integration.

Stacking Polymorphism in PtSe Drastically Affects Its Electromechanical Properties.

PtSe is one of the most promising materials for the next generation of piezoresistive sensors. However, the large-scale synthesis of homogeneous thin films with reproducible electromechanical properties is challenging due to polycrystallinity. It is shown that stacking phases other than the 1T phase become thermodynamically available at elevated temperatures that are common during synthesis.

Nanoelectromechanical Sensors Based on Suspended 2D Materials.

The unique properties and atomic thickness of two-dimensional (2D) materials enable smaller and better nanoelectromechanical sensors with novel functionalities. During the last decade, many studies have successfully shown the feasibility of using suspended membranes of 2D materials in pressure sensors, microphones, accelerometers, and mass and gas sensors. In this review, we explain the different sensing concepts and give an overview of the relevant material properties, fabrication routes, and device operation principles.

Gate-tunable graphene-based Hall sensors on flexible substrates with increased sensitivity.

We demonstrate a novel concept for operating graphene-based Hall sensors using an alternating current (AC) modulated gate voltage, which provides three important advantages compared to Hall sensors under static operation: (1) The sensor sensitivity can be doubled by utilizing both n- and p-type conductance. (2) A static magnetic field can be read out at frequencies in the kHz range, where the 1/f noise is lower compared to the static case. (3) The off-set voltage in the Hall signal can be reduced.

Unfavorable Structural and Functional Outcomes in Myelin Oligodendrocyte Glycoprotein Antibody-Associated Optic Neuritis.

Background: Recurrent optic neuritis (rON) associated with myelin oligodendrocyte glycoprotein (MOG)-specific antibodies has been initially reported to show a better clinical outcome than aquaporin-4 (AQP4)-seropositive ON in neuromyelitis optica spectrum disorder (NMOSD). Here, we characterize clinical and neuroimaging findings in severe cases of MOG antibody-positive and AQP4 antibody-negative bilateral rON.

Methods: Three male adults with rON (ages 18, 44, and 63 years) were evaluated with optical coherence tomography (OCT), MRI, cerebrospinal fluid (CSF), and serological studies.

Multicenter reliability of semiautomatic retinal layer segmentation using OCT.

Objective: To evaluate the inter-rater reliability of semiautomated segmentation of spectral domain optical coherence tomography (OCT) macular volume scans.

Methods: Macular OCT volume scans of left eyes from 17 subjects (8 patients with MS and 9 healthy controls) were automatically segmented by Heidelberg Eye Explorer (v1.9.

Retinal Ganglion Cell Topography in Patients With Visual Pathway Pathology.

Background: To investigate and quantify the impact of intracranial lesions at different locations within the visual pathway on the ganglion cell layer-inner plexiform layer (GCL-IPL) complex and the retinal nerve fiber layer (RNFL).

Methods: Patients with intracranial lesions affecting the optic chiasm (Group I) or the optic tract and/or lateral geniculate nucleus (Group II) were included. All patients received kinetic visual field assessment and underwent spectral domain optical coherence tomography.

Optical Coherence Tomography in Multiple Sclerosis.

Retinal optical coherence tomography (OCT) has recently become a vital tool for clinicians and researchers in ophthalmology and, increasingly, in neurology. Optical coherence tomography is quickly and easily performed, well-tolerated by patients, and allows high-resolution viewing of unmyelinated axons and other retinal structures in vivo. These factors have led OCT to find favor as a method of quantifying neuroaxonal loss in multiple sclerosis (MS), and the increasing acceptance of the anterior visual pathway as a model to investigate MS in humans.

Retinal thickness measured with optical coherence tomography and risk of disability worsening in multiple sclerosis: a cohort study.

Background: Most patients with multiple sclerosis without previous optic neuritis have thinner retinal layers than healthy controls. We assessed the role of peripapillary retinal nerve fibre layer (pRNFL) thickness and macular volume in eyes with no history of optic neuritis as a biomarker of disability worsening in a cohort of patients with multiple sclerosis who had at least one eye without optic neuritis available.

Methods: In this multicentre, cohort study, we collected data about patients (age ≥16 years old) with clinically isolated syndrome, relapsing-remitting multiple sclerosis, and progressive multiple sclerosis.

Retinal pathology in idiopathic moyamoya angiopathy detected by optical coherence tomography.

Objective: To investigate whether patients with moyamoya angiopathy without obvious retinal pathologies such as retinal infarctions or the congenital morning glory anomaly may have subtle subclinical retinal changes.

Methods: In this cross-sectional study, spectral domain optical coherence tomography was used to analyze the retinal morphology of 25 patients with idiopathic moyamoya angiopathy and 25 age- and sex-matched healthy controls. We analyzed the retinal vasculature with blue laser autofluorescence, lipofuscin deposits with MultiColor confocal scanning laser ophthalmoscopy, and the optic nerve head (ONH) volume with a custom postprocessing algorithm.