Scanning Electron Microscope Essay

Scanning Electron Microscope Essay

Length: 921 words (2.6 double-spaced pages)

Rating: Better Essays

Open Document

Essay Preview

In the forensic science field there are various machines used to examine physical evidence. One of those instruments is the scanning electron microscope (SEM). This instrument can be used in examining physical evidence found at crime scenes. There have been a number of scientists that have developed and improved the SEM. SEM is very significant in forensics because it can narrow down size, shape, and chemical composition. The scanning electron microscope is always growing and becoming a great impact on forensic science.
We will start of learning where the scanning electron microscope (SEM) began. Knoll built the first scanning microscope in 1935; he was not using demagnifying lenses. Von Ardenne expressed the theoretical philosophy underlying the scanning electron microscope. Developing the first scanning electron microscope in 1942 was Zworykin. This microscope was more improved due to using an electron multiplier tube as a preamplifier off the secondary electrons emission current. The resolution on the SEM was 50 nm (Physics Emory). Improving the SEM that Zworykin had developed, Oatley used nonlinear signal amplification. He was also the first to place in a stigmator in the SEM, which was used to correct lens cylindrical imperfections. In 1960, Everhart and Thornley improved the secondary electron detection. Three years following that Pease and Nixon, combined all the improvements in one microscope. The first commercial scanning electron microscope was developed in 1965 by the Cambridge Scientific Instruments Mark I (Physics Emory).
The scanning electron microscope has 10 parts to it which are the secondary detector, x-ray detector, backscatter detector, sample chamber, objective lens, electron beam, condenser lens, anode, ...

... middle of paper ...

...nated is very significant in criminal cases. We have reviewed the history and parts of the SEM, how it works, how it can aid in solving cases, and an actual case it was used to find the murderer. Scanning electron microscope is very significant and it will continue to be in the future.

Works Cited

Atteberry, J. (n.d.). How stuff works:How scanning Electron Microscopes Work. Retrieved from how stuff works:
Khursheed, A. (2011). Scanning Electron Microscope Optics and Spectrometers. Danvers: World Scientific Publisher.
Physics Emory. (n.d.). Retrieved from Physics Emory:
Swapp, S. (n.d.). Geochemical Instrumentation and Analysis. Retrieved from Carleton:

Need Writing Help?

Get feedback on grammar, clarity, concision and logic instantly.

Check your paper »

Essay on Materials And Methods Of Heat Treatment Of Whey

- Materials and Methods Heat treatment of whey WPC (10%, w/v), prepared by ultra-filtration, was obtained from Agropur Cooperative (Saint-Hubert, QC, Canada). WPC samples were thermally denatured at 100°Cfor 5min followed by rapid cooling in an ice bath. 2.2 Shearing Shearing was employed simultaneously with thermal denaturation using a Caframo stirrer BDC 6015 (Caframo Limited, Georgian Bluffs, Ontario, CA) equipped with a 4-bladed propeller rod with a diameter of 45 mm submerged in the whey solution....   [tags: Milk, Cheese, Scanning electron microscope, Whey]

Better Essays
1313 words (3.8 pages)

Essay on A Short Note On The Rejection And Passage

- 2.6. Rejection and Passage 119 To easily go on study, β2-Microglobulin (β2-MG) and human serum albumin were replaced by 120 lysozyme (LZM) and Albumin from bovine serum (BSA). LZM and β2-MG have the similar molecular 121 weight as LZM is 14 KDa while β2-MG is 11.8 KDa. The molecules of them are both positive charge 122 and globulin. At the same time, isoelectric point of them is relatively similar (LZM was 4.6 and β2- 123 MG 5.7). The molecular weight of BSA is 67 KDa while human serum albumin is 69 KDa....   [tags: Blood, Coagulation, Scanning electron microscope]

Better Essays
945 words (2.7 pages)

Essay on Comparing the Light and Electron Microscope

- Comparing the Light and Electron Microscope In this essay I am going to be comparing the light and electron microscope, I will look at the advantages and disadvantages of each microscope and then analyse my findings to see if one is better than the other. The light, or optical microscope as it is also known was invented in the 17th century, it has been refined in many ways over the years but it is essentially still the same. The light microscope works by; light rays from a light source beneath the stage are through to glass lenses in series....   [tags: Papers]

Better Essays
846 words (2.4 pages)

Essay about Electron Microscope

- Electron Microscope An electron microscope has many uses today, mainly to do with scientific study. The electron microscope has been developed to look at the tiniest structures, arrangements and components; it can magnify an object two million times. It works by using electrons instead of light. The electrons can fit through smaller gaps in specimens creating a clearer magnified image. There are two types of electron microscope, a scanning electron microscope and a transmission electron microscope....   [tags: Free Essays]

Free Essays
410 words (1.2 pages)

Electron Microscope Essay

- Electron Microscope The electron microscope has become one of the most widely utilized instruments for materials characterization. An electron microscope is a scientific instrument that allows us to “see” objects so small that they cannot be seen in any other way. (CITE) Electron microscopes have allowed scientists to see individual molecules and atoms for the first time. Most microscopes, including those in schools and laboratories today, are optical microscopes. They use glass lenses to enlarge, or magnify, an image....   [tags: science]

Better Essays
857 words (2.4 pages)

The Principles and Limitations of Transmission and Scanning Electron Microscopes

- The Principles and Limitations of Transmission and Scanning Electron Microscopes Introduction Microscopy has a major role in cytology.From the very beginning researchers have tried to develop ways of looking directly at living cells.This examination has revealed much about the morphology of cells and tissues.In recent years,development in microscopes,dyes,staining and preparatory techniques have helped reveal even more about the structure and function of cells.Microscopes have a certain magnification and resolving power.In any microscope the the resolving power is more important than the magnification.The resolving power of a microscope is the least distance b...   [tags: Papers]

Better Essays
850 words (2.4 pages)

Electron Microscopy and the Study of the Cell Essays

- Electron Microscopy and the Study of the Cell Electron Microscopes have revolutionised today’s understanding of the cell. In 1838 Scheleiden, a botanist theorised that the basic unit of a plant was a cell, the following year the scientist Schwann came up with a similar hypothesis this time related to animal cells, their combined ideas gave us the cell theory, the idea that all living things were made from similar building blocks, cells. It took 100 years before this idea was confirmed with the invention of the electron microscope....   [tags: Papers]

Free Essays
719 words (2.1 pages)

Essay on Electron Microscopy Investigation

- Electron Microscopy Investigation The electron microscope was first made when biologists found a problem with the resolution of a light microscope. Resolution means “the ability to distinguish between two points”; the problem is that the maximum resolution of a light microscope is 200nm. So if two points are closer together than 200nm they are seen as one. One example of this problem is that under a light microscope the centrioles in an animal cell appear as one, however when viewed under an electron microscope we can see that there are two centrioles at right angles to each other....   [tags: Papers]

Free Essays
694 words (2 pages)

Essay on Scanning Electrochemical Microscopy

- Scanning electrochemical microscopy (SECM) is a technique that is part of a broader range of techniques that are commonly referred to as scanning probe microscopy. It has a wide array of applications in chemistry, biology, and even the material sciences. SECM uses a ultramicroelectrode to measure the local electrochemical behavior of a substrate in a solution. When introduced, the ultramicroelectrode acts as the electron conductor in the substrate and the added electrolyte acts as the ionic conductor in the solution....   [tags: chemistry, biology, instrument]

Better Essays
1911 words (5.5 pages)

Essay about Microscope Types

- Microscope Types The most widely used microscopes are optical microscopes, which use visible light to create a magnified image of an object. The simplest form of optical microscope is the double-convex lens with a short focal length. These lenses can magnify an object by up to 15 times. In general, however, a compound microscope is used, which has multiple lenses to provide more magnification than a single convex lens could alone....   [tags: Papers]

Better Essays
1300 words (3.7 pages)