Introduction of Nanotechnology
Applications of Nano technology
Scanning Electron Microscope
Principle
Construction
Working
Advantages
Dis-Advantages
Conclusion
References
3. Introduction of Nano-Technology
Nanotechnology:
(1) The manipulation of matter at the atomic and molecular
scale.
(2) Potential applications in electrical engineering.
(3) Enhanced performance, miniaturization, and energy
efficiency.
(4)Definition :- Nano-Technology is the creation and
utilization of materials, devices , and systems through the
control of matter on the nanometer (1 to 100 nanometers)
length scale.
4. A Famous professor of physics Dr.
Richard P. Feynman was presented
first in 1959.
Invention of the scanning tunnelling
microscope [STM] in 1981 and the
discovery of fullerences [C60] in 1985
lead to the emergence of
Nanotechnology.
The term of Nano-Technology had
coined by Nario Tangiguchi in 1974.
Introduction of Nano-Technology
5. application of nanotechnology in Electrical Engineering
Scanning Electron Microscope :-
Scanning electron microscope [SEM] is an
improved model of an electron microscope. SEM is
used to study the three dimensional image of the
specimen.
Principle :-
When the accelerated primary electrons strikes the
sample, it produces secondary electrons. These
secondary electrons are collected by a positive
charged electron detector which in turn gives a 3-
dimensional image of the sample.
6. Construction of Scanning Electron Microscope
It consists of an electron gun to
produce high energy electron beam. A
magnetic condensing lens is used to
condense the electron beam and a
scanning coil is arranged in-between
magnetic condensing lens and the
sample.
The electron detector is used to
collect the secondary electrons and
can be converted into electrical
signal. These signals can be fed into
CRO .
7. Working of Scanning Electron Microscope
1) An electron source, such as a heated
tungsten filament or a field-emission source,
generates a beam of electrons.
2) Electromagnetic lenses in the electron gun
accelerate and focus the electron beam.
3) The beam is scanned across the sample's
surface in a raster pattern using
electromagnetic scanning coils.
4) Interactions between the electron beam and
the sample surface result in the emission of
various signals, including secondary
electrons, backscattered electrons, and X-
rays.
8. 7. Signal processing and image formation algorithms use the electrical
signals to generate a two-dimensional image of the sample's surface.
8. The image can be viewed and analyzed on a display screen.
9. SEM can provide high-resolution images revealing fine details of the
sample's topography and composition.
10. Various techniques like energy-dispersive X-ray spectroscopy (EDS)
can be used to analyze the elemental composition of the sample.
11. SEM is widely used in scientific research, materials science,
semiconductor analysis, and other fields for its ability to provide detailed
surface imaging and analysis.
5. Different detectors, such as secondary electron detectors and
backscattered electron detectors, collect these signals.
6. The collected signals are amplified and converted into electrical signals.
9. Advantages of Scanning Electron Microscope
Scanning electron microscopes are easy to use.
They can produce and generate results in digital format.
Scanning electron microscopes are able to provide quick results,
i.e., data can be obtained within a few minutes.
A scanning electron microscope requires minimum sample
preparation.
The resolution of scanning electron microscopes is significantly
high.
10. Dis-Advantages of Scanning Electron Microscope
Scanning electron microscopes are comparatively expensive.
Some microscopes must fulfil certain special conditions before their use. For instance, the room must be
free of vibrations and electromagnetic radiation.
Scanning electron microscopes have a bulky structure.
A cooling system should be attached with such microscopes.
The sample to be examined with the help of a scanning electron microscope needs to be solid in nature.
A scanning electron microscope can not be used for light materials such as hydrogen, helium, lithium,
etc.
Scanning of living samples with the help of a scanning electron microscope is not possible.
11. Conclusion :-
In conclusion, nanotechnology has revolutionized the field of scanning electron microscopy
(SEM) and brought forth significant advancements. The application of nanotechnology in
SEM has enabled enhanced imaging capabilities with higher resolution and improved
sensitivity. This technology has opened up new avenues for studying nanoscale structures,
materials, and biological specimens. Furthermore, nanotechnology-based SEM techniques
have facilitated precise manipulation and characterization of nanoparticles, leading to
breakthroughs in various fields including materials science, electronics, and medicine. The
integration of nanotechnology and SEM holds great promise for future advancements in
nanomaterials, nanodevices, and nanomedicine, paving the way for innovative technologies
and novel discoveries.
12. References
1. Moeini, H., Salimi, M., & Madani, S. (2018). Nanotechnology in scanning electron
microscopy. In Scanning Electron Microscopy (pp. 55-68). IntechOpen.
2. Gómez-Graña, S., Fernández-Pérez, M., & De La Fuente, J. M. (2017). Nanotechnology and
scanning electron microscopy: A perfect match for biological research. Micron, 102, 9-18.
3. Ding, W., Wang, Z., & Zhu, J. (2018). Application of nanotechnology in materials science.
Journal of Nanoscience and Nanotechnology, 18(2), 769-785.
4. Oatley CW, Nixon WC, Pease RFW (1965) Scanning electron microscopy. Adv Electronics
Electron Phys 21, 181–247.
5. Zworykin VA, Hillier J, Snyder RL (1942) A scanning electron microscope. ASTM Bull 117,
15–23.