On a pixeline black and white film we see gymnast Sanne Wevers on the beam, during the qualification at the Paris 2024 Olympic Games. This is one of the fragments on the nano scale of Dutch athletes made at the Nanolab in Twente. “Wevers’ bun was a micrometer in our frames – that is a hundred times smaller than the thickness of a sheet of paper,” says Femke Witmans.
Witmans obtained his PhD on 20 June at the University of Twente to investigate the properties of wafer -thin Nanodraden, which are a thousand times thinner than a hair. This is a promising material for future quantum computers and energy-efficient electronics. “But before the time comes, we have to better understand this material by measuring how electricity moves exactly through such a thread,” says Witmans.
During her research, Witmans made at least forty chips of a square centimeter in size on which she manually applied a few dozen nano wire and connected with tiny electronic components. “I think I have made around 1,500 measuring structures of a few micrometer in the past four years,” she says in one of the labs where she worked. The large numbers were needed because the systems regularly broke and to be able to do different tests with different materials.
In the lab, she plucked through a microscope, nano wire of a growth surface to place them on her measuring chip. She then applied the required electronic components that she connected to the nanod wires by stringing thin, spider -like threads in between. “For that I used a miniscule needle. If the thread came from it, I have to piege it again.”
That Priegelwerk went so well that she spent extra hours in the lab last summer, with three fellow promotingi to immortalize top athletes on the nano scale-under the name Nanolympics. Nine nanofilmjes from, among others, the final of Rower Karolien Florijn, the Team Sprint Baanwielrennen and the sensational relay sprint from Femke Bol, they shared on social media.
How did you come up with the idea of Nanolympics?
“We wanted people to get acquainted with nanotechnology outside of the UT and show what we can make on this small scale. There is a lot of innovation in that area. Because we all love sport, we came up with the idea of making – lending on the Olympic Games – athletes on nano scale. We started a fragment of a day. We also got a fragment with we started playing a half -year. So we have reached our goal. “
How do you make such a nanofilm?
“After we chose a fragment, we made a kind of Stop Motion-Movie by cutting it in 15 frames per second. I converted the pixels of the video frames on the computer. We then signed those cubes on a chip of 5 by 5 millimeters with electron lithography. With a bundle of electrons you can shoot holes in an electron -sensitive layer on the chip. For example, we drew all frames of a fragment of a few seconds, pixel for pixel, next to each other on a chip.
“The pixels cubes were 300 nanometers (0.0003 millimeter) large and the athletes a few dozen micrometers (hundredths of a millimeter). We then filled those pixel hits with metal that reflects if you take a picture of it with an electron microscope-so you can make the type of at the picture of the small structures. By playing those frames quickly in succession, we made videos. ”
The nano wire can be building blocks for
A quantum computer
How did the Nanolympics relate to the PhD research?
“I use exactly the same manufacturing steps to make the measurement structures that I have investigated. But then there are nano wires of Tin-Telluride between the metal structures of which I have measured electrical properties.”
Why are those wires interesting?
“In theory, the so-called topological insulators should be. That its materials that lead the stream on the surface and are insulating inside and therefore do not conduct any current. That is special, because normally a material is a conductor or an insulator. That material feature is interesting on fundamental level. experiences.
“It becomes even more interesting if you cover the nano wires with a super conductor – that is a material that leads resistance -free and therefore very efficiently electricity.”
What can you do with that?
“In nano wires that are covered with a super conductor, so -called majorana states could occur. In addition, electrons in the material in certain places collectively behave like a sort of particle.
“Nanodraadjes with majorana states could serve as building blocks for a so -called topological quantum computer that promises to be less error -sensitive than other types of quantum computers. But for the time being they only exist on paper.
“The aim of my research was to investigate whether nano threads from Tin-Telluride, covered with the super-conducting material Niobium, are suitable for detecting these majorana stands.”
Did that succeed?
“I have never made a system in which you could detect majorana stands. And when measuring the material properties I found out that the inside of the nanodraadjes is not insulating, as the theory predicts. It turned out that the bare surface was better to conduct electric current than the inside. disrupts.
“I also looked at combining a nano wire with a super conductor. In this way it was possible to get super guide to the surface of the nano wire. That is a nice step towards majorana states.”