Transmission electron microscopes can image at substantially better resolution than light microscopes because electrons have a shorter de Broglie wavelength. This allows the instrument to record exquisite detail, down to a single column of atoms, which is thousands of times smaller than a resolvable object observed with a light microscope. Transmission electron microscopy is an important analytical technique in the physical, chemical, and biological sciences.
Principle and Methodology of TEM
The Transmission Electron Microscope (TEM) operates similarly to a light microscope but uses a beam of electrons to focus on a specimen. Electrons have a shorter wavelength than light, and the resolution power increases as the electron illuminates the specimen. This results in a resolution power of about 1000 times higher than that of a light microscope, as the electron’s wavelength is about 0.005nm, which is 100,000 times shorter than light. Therefore, TEM offers better resolution than a light microscope.
Instrumentation of TEM
TEMs consist of five basic components:
- High voltage source.
- Vacuum system
- Microscope column
- Detectors (such as image cameras and spectrometers)
- Control computers and software.
Applications of TEM
TEM is applied in a wide range of fields. From biology, microbiology, nanotechnology, forensics, and so on. Some of these applications are:
- Visualize and examine the cell structures of bacteria, viruses, and fungi.
- To see bacterial flagella and plasmids
- View the shapes and sizes of microbial cell organelles.
- To investigate and distinguish between plant and animal cells.
- It’s also used in nanotechnology to investigate nanoparticles like ZnO nanoparticles.
- It detects and identifies fractures and broken microparticles, allowing the particles to repair themselves.
