Hello and welcome. Today we are going to talk about those fascinating devices that allow us to observe tiny objects in great detail. We are talking about microscopes. Today we will focus on talking about the different types of these, so pay close attention.
A brief history of microscopes
Like many other technological devices, microscopes have a very long history. The first microscopes contained a simple loupe with little power (up to 10 times). They were used to observe small insects such as fleas.
The first versions of light microscopes were developed in the late 15th century. The use of microscopes for the study of organic tissues appeared only in 1644 and today, a few centuries later,we have microscopes that can provide a resolution of 50 picometers with magnifications of up to 50 million times.< /p>
This is sufficient to observe the ultrastructure of a variety of inorganic and biological samples. Modern microscopes can be classified in different ways. One way to group them is how they interact with samples to create images. Based on the same factor, we have listed 5 main types of microscopes and their uses.
Light microscopes, are the most common microscopes, which use light to pass through a sample to generate images. They can be very simple in design, although sophisticated light microscopes aim to improve the resolution and contrast of the sample.
These can be divided into two types: simple and complex microscopes. A simple microscope uses one lens (such as a magnifying glass) to magnify a sample, while a complex microscope uses multiple lenses. They are often equipped with a digital camera, so the sample can be viewed with a computer.
An electron microscope uses a beam of accelerated electrons to obtain images of a sample. In the same way that light microscopes use glass lenses, electron microscopes use contoured magnetic fields to create optic-electronic lens systems.
Because the wavelength of the electron can be much shorter than that of the photon, electron microscopes have higher resolution and magnification than conventional light microscopes.
Scanning probe microscope
Scanning probe microscopy was discovered in 1981,for imaging the surface of a sample at the atomic level. It uses a physical probe to scan the sample and generate highly magnified images.
Depending on the purpose of the study, different methods are used in scanning probe microscopy. For example, the instrument can be set to "tapping" mode, in which the cantilever oscillates so that the tip periodically touches the surface of the sample. Primarily used to examine samples with soft surfaces.
Scanning Acoustic Microscopes
A scanning acoustic microscope measures changes in acoustic impedance using sound waves. Primarily used for non-destructive evaluation, failure analysis, and detection of defects within materials, including those found in integrated circuits.
This type of microscope was first developed in 1974 at the Stanford University Microwave Laboratory. Since then, numerous improvements have been made to improve its accuracy and resolution.