We’ve all grown up with our own favorite superheroes. Maybe you spent endless hours curled up with the comic books of Wonder Woman, or secretly imagined what it would be like to defy the city skies as Spider-Man. But even if you’re not familiar with superhero comic books, it’s hard to miss their adventures on the big screen these days.
In this series, Wtnschp is creating a ‘Marvel/DC Universe’ of its own. Like most superheroes, VUB scientists are just ordinary people using their smarts and talents to do good in the world. And just like Batman is inextricably linked to his Batmobile, or Iron Man to his high-tech suit, our researchers have their own supergadgets. With the help of FWO funding, 8 VUB research groups have acquired some new high-tech equipment that will blow your mind. Next up is research group SURF with their ‘XPS’, an X-ray supertool that helps them uncover secrets just below the surface.
The research group Electrochemical and Surface Engineering (SURF) completely evolves around metals. Think about the metals that you can find in soda cans, trains, electrical wiring, but also the use of metals in the newest electric cars or the behavior of metals when they are taken into space. We look at how the metals behave and change, and how we can change them. One way to modify metals is by adding a lick of paint on top, to protect them from corroding in the rain. But we can also change the outermost atoms of the metal itself! This way, we can change how well a metal reacts with the environment, how well the paint sticks, …
As we like to dive in deep and look at metal on such a tiny atomic scale, highly sensitive equipment is necessary. SURF is the proud owner of a very large set of tools, all having their dedicated purpose. Even more, the SURF collection is quite unique in its size. Most of the equipment uses electron and photon guns to create spectra: by shooting electrons or X-rays on a piece of metal, we provoke new electrons or X-rays, that enable us to identify the atoms and molecules the metal is made from. Other equipment uses atomic sharp tips to see atoms: a needle ‘feels’ the surface and creates a picture with atomistic resolution.
” As we look at metal on such a tiny scale, highly sensitive equipment is necessary. “
X-RAYS SEE WHAT THE NAKED EYE CAN’T
The new equipment is an X-ray Photo-electron Spectroscope (XPS). It helps us figure out what the chemical structure of the outermost surface of a material looks like. X-rays are waves, that are also used in the hospital to make pictures from broken arms or legs when ski holidays end badly. Famously, Superman also has the power of X-ray vision. Apparently, in Superman: the movie (1978), his power even allows him to see through Lois Lane’s dress and determine the color of her underwear. The XPS machine might not be able to guess the color of your panties, but it has its own superpowers.
Atoms are made up of tiny elementary particles: protons and neurons in the middle, circled by electrons. These electrons do not like to leave the nucleus. However when the X-rays have enough energy, they can remove them! The electrons can escape from the outermost layer and we can measure them: they have a specific energy that tells us which atom or molecule they come from. This type of equipment is very surface sensitive, since it has the power to unravel chemical structures of the outer surface of things: we can see approximately 10 nanometers in depth – a nanometer is one millionth of a mm!
X-ray beam (blue) hits, forcing an electron (red) to escape.
XPS has been an indispensable tool for decades in our research group. The ease of use of the XPS devices has exponentially increased. For example, we started out doing a lot by hand, leading to regular loss of vacuum and hence measurement time. We don’t do the measurements in the open air, but in a special chamber where there are no molecules in the environment that can influence our measurement. Every time we ‘lost’ the vacuum environment, we needed to pump almost a full day to get it back. Now we have fully automated insertion of the samples, and we no longer have to handle them one by one. As a consequence, the output exponentially increased as well! This newest version is a versatile one. It is comprised of the basic XPS, with addition of a lot of new features that will bring not only submicron lateral resolution (every point that we measure on the surface is closer than a micrometer to the next point – old equipment has such a resolution of more than 400 micrometer!), but also enable atom by atom surface layer removal and give the opportunity to connect a ‘train’ of new, complementary devices and synthesis techniques.
The new equipment takes up quite some space – and bringing it in the lab was a big challenge. The main warehouse of the university couldn’t host it, and we had to unpack the almost one million euros worth of infrastructure just at the street side. Laboratory staff was quickly transformed in safety personnel, while trained engineers moved the equipment to the final position in the building.
” Except for hydrogen and helium, we will be able to measure all elements – even kryptonite if it would exist “
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VUB researchers interested in acquiring scientific research infrastructure can contact the VUB Research and Grant Office (RGO@vub.be). They can assist you with your FWO application for medium-scale (150-1000k€) and large-scale (+1000k€) research infrastructure.
Stock images: © Shutterstock
Photos XPS: © SURF research group