Search results for " microscopy"

Macroporous Scaffolds Based on Chitosan and Bioactive Molecules†

2007

Chitosan-based macroporous scaffolds for tissue engineering applications are developed by cryogelation in aqueous media. The cryogels obtained are modified using a new RGD-containing peptide developed in this laboratory. A RGD-containing peptide is chemically attached to the surface of the cryogels to improve cell adhesion to the 3D-structure chitosan-based scaffolds. The synthesis, physico-chemical, and biological evaluations of the system are described, and the optimization of the formulations is carried out by varying the reaction parameters. Fibroblasts and endothelial cells are used in cell cultures to determine cell behavior and the cytocompatibility of the macroporous cryogels. Cell …

Reflection scanning microscopy.

1992

To image nontransparent samples we have utilized a special type of scanning-probe microscope that is referred to here as a reflection scanning microscope. The reflection scanning microscope provides a method for producing a scanned point light source as well as a system for collecting the light that is reflected by the sample. The system, which uses an optical fiber coupler, is easily installed on an existing photon scanning tunneling microscope. A calculation of the coupling coefficient between the natural propagation mode of the optical fiber and the light that is reflected by the sample is presented along with a comparison between calculated and measured values of the intensity of the li…

Imaging of surface plasmon propagation and edge interaction using a photon scanning tunneling microscope

1994

We report the direct imaging of surface plasmon propagation on thin silver films using the photon scanning tunneling microscope. It is found that the surface plasmon remains tightly confined in the original launch direction with insignificant scattering to other momentum states. A propagation length of 13.2 \ensuremath{\mu}m is measured at \ensuremath{\lambda}=632.8 nm. We also present images showing the interaction of a surface plasmon with the edge of the metal film supporting it. The most remarkable feature is the absence of specularly reflected beam.

A computer controlled patterning system for scanning probe microscopes

1999

Abstract A pattern generator system for lithography based on scanning force microscopes has been developed. Patterns to be miniaturized onto a chip can be scanned or drawn by any common graphical program. The pattern file is used to control a voltage simultaneously with the microscope probe scanning the surface of the substrate. The voltage can be used in numerous different ways to manipulate the substrate, depending on the lithographic method preferred. We have demonstrated the system by adding this voltage to the z -piezo voltage of the scanner, in order to make the probe plow the pattern into a film spinned on the sample. To maintain linearity in zooming in and rotating the scanning dire…

Studies on atomic layer deposition of IRMOF-8 thin films

2015

Deposition of IRMOF-8 thin films by atomic layer deposition was studied at 260–320 C. Zinc acetate and 2,6-naphthalenedicarboxylic acid were used as the precursors. The as-deposited amorphous films were crystallized in 70% relative humidity at room temperature resulting in an unknown phase with a large unit cell. An autoclave with dimethylformamide as the solvent was used to recrystallize the films into IRMOF-8 as confirmed by grazing incidence x-ray diffraction. The films were further characterized by high temperature x-ray diffraction (HTXRD), field emission scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), time-of-flight elastic recoil detection analysis (TOF-…

Identification of Chinese fresh-water pearls using MN2+ activated cathodoluminescence

2000

Fresh-water tissue graft-cultured pearls from China were investigated using hot cathode and cold cathode cathodoluminescence microscopes. Supplementary investigations were done using X-radiography, a Scanning Electron Microscope, an optical microscope, and an Atomic Force Microscope (AFM). The results were compared with those of natural fresh-water pearls from the Mississippi river. Thin sections of fresh-water natural pearls from the Mississippi river could be distinguished from those of fresh-water tissue graft cultured pearls from China using a hot cathode cathodoluminescence microscope according to the distribution of Mn2+ as follows: (1) Fresh-water tissue graft cultured pearls from Ch…

Imaging of Located Buried Defects in Metal Samples by an Scanning Microwave Microscopy

2011

Abstract A non-destructive method is proposed to detect the located buried defects using scanning microwave microscopy. Based on the “skin effect”, our recent developments authorize 3D tomography with nanometric resolution. This technique associates the electromagnetic microwave measurement using a Vector Network Analyzer (VNA) with the nanometer-resolution positioning capabilities of an Atomic Force Microscope. At each used frequency, an incident electromagnetic wave is send to the sample and the reflected wave gives information on a specific depth layer in the material. With a large bandwidth of frequencies, a 3D tomography is allowed inside the material. With characteristic tools of nano…

<title>Scanning probe microscopy of nanocrystalline iridium oxide thin films</title>

2003

Structural investigations of nanocrystalline iridium oxide thin films, prepared by dc magnetron sputtering technique were performed by scanning probe microscopy (SPM). SPM studies, using both atomic force microscopy (AFM) and scanning tunnelling microscopy (STM), indicate that the thin films are composed of grains with a size of about 20-50 nm. Fine crystallinity and small RMS microroughness of the films, being well below 2 nm, make iridium oxide thin films promising candidates for nanolithographic applications. The possibility to perform nanolithograhpic processes at a scale of less than 150 nm was successfully examined in AFM and STM modes.© (2003) COPYRIGHT SPIE--The International Societ…

Watching Ions Move: Scanning Probe Microscopy on Perovskite Solar Cells

2018

Field-induced tip–sample oxygen transfer in scanning tunneling microscopy on TiO2(110) (1 1).

2008

International audience; A study on the field-induced tip–surface oxygen transfer at room temperature and its influence on the tunneling conditions for stable STM imaging of the TiO2(110) (1 1) surface is reported. A simple model of field-induced transfer is applied to tungsten and platinum–iridium tips. The oxygen transition rates from the sample to the tip or from the tip to the sample depend on the oxygen desorption barriers formed at tunneling distance. For stable imaging the applied bias voltage has to balance the oxygen transfer probabilities in both directions. In the case of Pt/Ir tips, the tunneling conditions for images with clear evidence of bridging oxygen point defects have been…