Scanning Electron Microscope/Transmission Electron Microscopy
CABER has access to a range of equipment within the recently launched MSSI Microscopy Suite. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) are powerful techniques for characterising biomaterial surfaces.
In these microscopes, electrons are directed through a series of lenses onto a sample. Many different types of electrons are then detected by various detectors. With the recent developments in the electron source and the advancement in the technologies of the detectors, higher resolutions have been achieved that can be utilised to examine beam sensitive material, nanomaterials and crystalline structure.
Figure: Scanning Electron / Transmission Electron Microscopy facilities available
A JEOL JCM-5700 CarryScope and a Hitachi SU-70
HRSEM are available for SEM imaging. The Hitachi SU-70 is a multipurpose, high
resolution, scanning electron microscope with a thermal field emission source.
With upper and lower detectors, secondary electron imaging with a resolution of
1 nm can be achieved whilst keeping topographical data. There is also a
dedicated back scattered electron (BSE) detector, allowing for images with
contrast relating to the atomic weight of the elements in the sample. Both
energy dispersive X-ray spectroscopy (EDS) and wavelength dispersive X-ray
spectroscopy (WDS) are available to determine the elemental composition of a
specimen or area of interest. Electron back scattered diffraction detector
(EBSD) can be used to investigate and map crystal grain boundaries in materials
down to ~0.1 um.
TEM analysis is provided via a JEOL JEM-2100F high resolution, electron
microscope with a field emission source. Standard analysis techniques available
include bright-/dark field imaging, high resolution lattice imaging and electron
diffraction. In addition, there is a STEM attachment, which simultaneously
obtains bright field (BF) and high angle annular dark field (HAADF) atomic
resolution images. The microscope also includes an SEI/BSE detector enabling
topographical data to be collected. The energy dispersive X-ray analyser allows
qualitative/quantitative elemental composition analysis even at atomic
resolution.