Helium microscope

• The World-first scanning helium microscope has been built by Australian researchers.
• This discovery “open doors” for many new discoveries by allowing scientists to scrutinize materials without disturbing them.
• Traditional microscopes use light to penetrate samples and this can damage them.
• The scanning helium microscope means the samples will be analyzed in their true state and
• will enable scientists to study human, animal and plant samples, as well as computer chips and pharmaceutical drugs, without damaging or changing them.

Applications:

• The microscope could be useful in major industries such as solar energy, defence, explosives and information technology.
• The new device is expected to pave the way for many new discoveries, because it gives new insight on structures at a microscopic level.
• The technology may help find ways of removing carbon monoxide from exhaust gases.
• It could help with the clean-up of toxic or even radioactive spills, without harming the surrounding flora or fauna.
• Defence experts will also be interested because it could lead to the development of stealth technology and new explosives.

Different Types of microscope:
Optical Microscopes:
Optical microscope uses visible light (or UV light in the case of fluorescence microscopy) to sharply magnify the samples. The light rays refract with optical lenses. Dating back to the first microscopes that were invented, it is found that they belonged to this category. Optical microscopes can be further subdivided into several categories:

• Compound Microscope: The compound microscope is built of two systems of lenses for greater magnification (an objective and an ocular: eye piece). The utmost useful magnification of a compound microscope is about 1000x.
• Stereo Microscope (dissecting microscope): The stereo microscope is an optical microscope which magnifies up to about maximum 100x and provides a 3-dimensional view of the specimen. Stereo microscopes are highly useful for observing opaque objects.
• Confocal Laser scanning microscope: Unlike compound and stereo microscopes, Confocal Laser scanning microscopes are reserved for research organizations. Such microscopes are able to scan a sample also in depth. A computer can then assemble the data to create a 3D image.

X-ray Microscope:
As the name suggests, these microscopes use a beam of x-rays to create an image. Due to the small wavelength, the image resolution is higher than in optical microscopes. The maximum useful magnification is therefore also higher and is between the optical microscopes and electron microscopes. One advantage of x-ray microscopes over electron microscopes is, that it is possible to observe living cells.
Scanning acoustic microscope (SAM):
These devices use focused sound waves to generate an image. They are used in materials science to detect small cracks or tensions in materials. SAMs can also be used in biology where they help to uncover tensions, stress and elasticity inside biological structure.

Neutron Microscope:
These microscopes are still in an experimental stage. They have a high resolution and may offer better contrast than other forms of microscopy.
Electron Microscopes:
Modern electron microscopes can magnify up to 2 million times. This is possible, because the wavelength of high energy electrons is very small. At the same time, the high energy electrons are pretty tough on the sample being observed. It may take a long time to completely dehydrate and prepare the specimen. Some biological specimens also need to be coated with a very thin layer of a metal before they can be observed. Types:

• Transmission electron microscopy (TEM): In this case, the electron beam is passed through the sample. The result is a two dimensional image.
• Scanning electron microscopy (SEM): Here the electron beam is projected on the sample. The electrons do not go through the sample but bounce off. This way it is possible to visualize the surface structure of the specimen. The image appears 3 dimensional.

By: Vishal