Text written in Basque and translated automatically by Elia without any subsequent editing. SEE ORIGINAL

High resolution microscopes

At the CIC NanoGune in San Sebastian, a new microscopy laboratory has been opened. They want to make the world invisible to our eyes visible there.

To this end, three electron microscopes will be used to disseminate and facilitate the study of the nanoworld. One of them can see atoms, the other is able to build nanostructures, and the third will study liquids in vacuum.

A common fly. Using the lens of the optical microscope, the eye becomes a network of cells.

Microscopes open a door to the universe of the little one. In this world, they have taken a giant step thanks to electron microscopes. In the new generation of microscopes, an electron beam replaces light, allowing access to the smallest structure.

ANDREY CHUVILIN; CIC nanoGUNE: The main problem is related to the wavelength of light. The wavelength of the light is approximately half a micron, which is the highest resolution we can achieve with the light wave.

The best optical microscopes today have a resolution of about 200 nanometers, but if we look inside this computer, we would see that some of the components of the computer are less than 100 nanometers.

The development of technology has allowed us to see more resolution within things on a very small scale. Fortunately, this was accompanied by the observation that the electrons were wave-like. So they began to study the wave nature of the electrons. [This is how the electron microscopes came in.]

Using the same sample in the scanning electron microscope, it can be introduced into each cell of the fly's eyes. The resolution is up to 1.5 nanometers.

For this purpose, the ESEM Quanta microscope is used, the simplest of the 3 microscopes available in the CIC nanoGune laboratory in San Sebastián.

In terms of appearance, it doesn’t look much like optical microscopes. It looks like a small armoured chamber. Inside, you can see the cannon that launches the electrons and the sensors that receive the signals that emit them.

Under normal conditions, the path of an electron is very short, a few centimeters before it is scattered or lost. When the chamber is closed, it must be evacuated, i.e. the wind exits. In the vacuum, the path of the electrons is prolonged.

After the electrons are launched, they collide on the sample and send three signals.

ANDREY CHUVILIN; CIC nanoGUNE: This would be the light source in a normal microscope; in this case, electrons are generated here from a filament and focus the lenses in the column... The lenses themselves are electromagnetic fields. The electron beam goes through here, passes through these lenses here, and is directed to the sample. The principle of this microscope is scanning. This is what it does: it directs the electron beam to the sample, which produces a series of signals, mainly secondary electrons, X-rays, bouncing electrons, and other signals, all of which we can detect. Then, we form the image from all these signals.

The operation is similar to that of a scanning electron microscope. But ESEM Quanta has the peculiarity that, unlike other electron microscopes, it is able to analyze wet samples, i.e. water, effluents, paints...

This is Titan, the most advanced TEM/STEM microscope on the market today. It has enough resolution to see atoms. The resolution is up to 0.08 nanometers.

ELIZAVETA NIKULINA; CIC nanoGUNE: Our center is called NANOGUNE. This means that we study processes and structures on a nanometric scale. That’s why we use this machine to study nanostructures

Even the room where this microscope is located is very special. It is adapted so that vibrations, electromagnetic interference, sounds or even the slightest dirt do not cause any inconvenience at the time of work. These accuracies are controlled by a sensor system.

ELIZAVETA NIKULINA; CIC nanoGUNE: This room is special. It has a cooling system of its own, these metal cooling panels here. It also has its own ventilation system. All this is to keep the temperature stable, reduce the vibration and also reduce the magnetic field. We also have a magnetic field and temperature recording system here. For what reason? Because we work with atoms, and they're very small.

We also have a wooden chair; with metal, if not... All the instruments in this room are very sensitive to magnetic fields. They also feel mobile phones.

At first glance, the size of the TITAN impresses. It has been built as a lego, joining pieces, so it can be configured by replacing or exchanging pieces according to the needs.

It is more than three meters from the base to the tip. This is because it requires a lot of energy. In order to provide a high resolution, electrons require a high energy, and in order to acquire this energy, they must reach a high velocity. For this, a long cannon is required.

To view the samples, the electron beam does not collide with the sample but passes through it. The microscope, so to speak, shows the shadow of the sample. For this purpose, it is very important that the sample is as thin as possible, such as about 100 nanometers.

The samples are polished using a HELIOS microscope.

HELIOS is much more than just a microscope. In addition to seeing samples, it is also capable of building nanostructures. For this purpose, in addition to the electron beam, the ion beam is also used for the work.

CHRISTOPHER TOLLAN; CIC nanoGUNE: We use this tool primarily to make nanostructures. Together with the images, we can also make objects. We can make holes, for example, or build towers. Things like that. We use an ion beam to make nanostructures. It uses heavier atoms and is suitable for drilling surfaces and such. Gases can also be used—gases are highly reactive—and under ion and electron beams, we can accumulate material and create structures.

With these three microscopes, several projects are currently being carried out, such as the use of viruses as templates to create nanostructures, that is, to use them as drug holders; to construct nanoantennas; or to visualize the interior of cells.