LVEM

Electron Microscopy

Unique concept based on ISO methodology
Fully automatic and semi automatic inspection
Digital control of all components
User friendly, powerful and highly adaptive software
Windows™ based operating system

Low Voltage Electron Microscope LVEM

Electron microscopes are indispensable tools for the investigation of objects at the micro and nano scale. The LVEM can help you get the information you need. The LVEM is designed to excel across a broad range of applications such as biology, medical diagnosis, and materials science (macromolecular chemistry). Using unstained samples you are able to observe the objects close to their native state with ultra high contrast and nanometer resolutions.

Small installation space

The LVEM is a compact bench top instrument that combines high-resolution imaging with the small footprint of an optical microscope. It consists of four separate parts; the microscope, the electronics unit, the vacuum system, and the PC. Small footprint, no need for a dark room, no cooling water, easy service all this makes the instrument a multi-purpose personal or in-group electron microscope.

High contrast

The LVEM is a unique investigation tool that allows observation of objects composed of light elements (H, C, N, O, S, P) with high contrast without using heavy metal staining and shadowing. Samples composed of heavier elements can also be observed either in nanometer scale outline detail or in aggregation (lower magnification) when placed in an appropriate embedding matrix or directly on a carbon coated grid. Thus both stained and unstained samples can be observed. High contrast of light elements is achieved through a substantial decrease of electron energy (see the comparison images below). An acceleration voltage decrease from 100 kV to 5 kV significantly increases electron scattering and enhances the contrast of standard test samples (20 nm thin carbon film) by more than 10 times. The spatial resolution of the LVEM is about 2 nm in all modes.

Microptik Low Voltage Electron Microscope LVEM principle Microptik Low Voltage Electron Microscope LVEM principle
Unstained thin section of rat heart (5 kV) Unstained thin section of rat heart (80 kV)

Field emission gun (FEG) and advanced electron optics

The design of the LVEM differs considerably from that of standard TEM. The miniaturized electron optics column is oriented upside down with the electron gun at the bottom side. Low voltage electron optics projects enlarged image on an electron-sensitive YAG screen; this image – which contains details at the nanometer scale – is further magnified by optical objective of a light microscope. The YAG scintillator serves as an image converter between the electron and light optics. The maximum magnification is approx. 200,000 in TEM mode. The overall dimensions of the LVEM are comparable with those of conventional light microscopes. Observation of the results is made through binoculars or on a screen via digital camera image capture.

Image capture

Microptik Low Voltage Electron Microscope LVEM analitic software
UTEM panel
Microptik Low Voltage Electron Microscope LVEM analitic software
Scan panel

A Retiga 4000R progressive-scan CCD camera is attached to the LVEM (2048?2048 pixels). The Qcapture PRO Image Processing Software is used for acquisition, documentation, and archiving, as well as measurement and analysis of high performance image data. Various image processing procedures for pre- and post-processing, such as arithmetic operations, baseline image subtraction, filtering and smoothing procedures. Scanning images can be saved in three resolution levels – 512?512, 1024?1024 and 2048?2048 pixels. Scanning images can be formed by detecting transmitted electrons (STEM – scanning transmission electron microscopy), or backscattered electrons (BSE). IN BSE mode the combination of image signals from two detector segments enables both material and topographic contrast images.

Wide choice of imaging modes

Even though the LVEM is the smallest commercial transmission electron microscope in the world, it features all the standard imaging modes that can be found in conventional TEMs and more. The LVEM can work in transmission (TEM – Transmission Electron Microscope) or diffraction (SAED – Selected Area Electron Diffraction) modes as well as in scanning modes (STEM – Scanning Transmission Electron Microscope and SEM – Scanning Electron Microscope with BSE – Backscattered Electrons) with nanometer spatial resolution.

The following combinations are available: 
TEM (with SAED) 
TEM (with SAED) + STEM 
TEM (with SAED) + SEM 
TEM (with SAED) + STEM + SEM

Applications

LVEM is a novel solution for imaging in life sciences and materials science (macromolecular chemistry). You can read more about LVEM and other applications on this page.

Easier sample preparation techniques

Conventional preparation techniques are simplified because staining and shadowing may be avoided. The observed image is the real structure without any artifacts stemming from staining or shadowing, closer to the native state of your samples. The sample thickness should be up to 50 nm in TEM mode, up to 70 nm in STEM mode, depending on the sample material. The samples are placed on standard 3 mm discs or grids.

Technical parameters

Accelerating voltage(nominal) 5 kV
Specimen III 3 mm TEM grids
specimen exchange time approx. 3 min
Electron optics
Condenser lens permanent magnet
focal length* 4.30 mm
the smallest illuminated area 100 nm
condenser apertures III 50, 30 mm
* calculated for 5 kV
Objective lens permanent magnet
focal length* 1.26 mm
CS 0.64 mm
CC 0.89 mm
dtheoretical 1.1 nm
atheoretical 10-2 rad
objective aperture III 50, 30 mm
* calculated for 5 kV
Projection lens (TEM) electrostatic
magnification on the YAG screen 36 to 470x
Electron gun
Shottky cathode ZrO/W[100]
current density
0.2 mA sr-1
lifetime > 2,000 hours
Light optics
objective Olympus M40x NA 0.90
objective Olympus M4x NA 0.13
binocular M10x  
Olympus U-TR30-2 widefield trinocular observation tube
TEM image capture
camera Retiga 4000R CCD
2,048x2,048 pixels
digitalization 12 bits
pixel size 7.4x7.4 mm
cooling optional Peltier cooling available
SCAN modes image capture
monitor 512x512 pixels
saving image up to 2,048x2,048 pixels
digitalization 8 bits
Imaging modes
TEM
resolving power 2.5 nm
total magnification 1,500 to 195,000x
ED (electron diffraction)
minimum probe size 100 nm
diffraction lens magnification 3.5x
STEM
resolving power 2.0 nm
minimum magnification (25x25 mm) 6,000x
SEM (BSE detector)
resolving power 4 nm
minimum magnification (200x200 mm) 800x
Vacuum
Airlock system (for sample exchange)
diaphragmal pump and turbomolecular pump 10-5 mbar
Object space
ion getter pump (10 lsec-1) 10-8 mbar
Electron gun
ion getter pump (7 lsec-1) 10-9 mbar
Weights and dimensions
Electron and light optic system
weight 25 kg
dimensions (wxdxh) without camera 290x450x455/510 mm
Airlock pumping system Pfeiffer Vacuum TSH 071E
weight 15 kg
dimensions 300x300x340 mm
Control electronics
weight 19 kg
dimensions (wxdxh) 470x270x290 mm
Consumption
Control electronics in stand by (ion getter pumps only) 20 VA
Control electronics 160 VA
Including airlock pumping system 300 VA
Camera 20 VA
PC and monitors approx. 450 VA
No cooling water is required.

Images and applications

Electron Diffraction mode

Diffraction from clay particles on carbon film   Diffraction pattern from Aluminium nanoparticles on carbon film
Diffraction from Molybden oxide single crystal Diffraction from Zinc oxide single crystal  
Ant eye coated by gold in BSE   Leg of tick coated by gold in BSE
Aluminum-Tungstan alloy in BSE Polymer foam coated by gold in BSE  
TEM mode STEM mode
Microptik Low Voltage Electron Microscope LVEM application TEM mode Microptik Low Voltage Electron Microscope LVEM application STEM mode