C2N, Scultting Matter

Transcription

Commentary – voice over
What are the laws that rule over the infinitely small? Can one sculpt matter on the nanometric scale, to the billionth of a foot? Since the emergence of quantum theories in the early 20th century, science has attempted to solve the mysteries of this world on the scale of the atom in which the properties of materials change radically. This research has led to the emergence of nanoscience and the fabrication of objects approximately 10,000 times smaller than a strand of hair.

To interact with this “nano-world”, scientists had to devise laboratories and machines to carry out extremely precise experiments. It was with this goal in sight that the Centre for Nanoscience and Nanotechnology, the C2N, was developed on the Plateau de Saclay, in the Paris region. A laboratory welcoming more than 400 scientists specialized in several research fields and home to a rare tool: one of the largest cleanrooms in Europe. This “nanotechnology plant” of 9,800 square feet contains all the necessary high tech equipment for the conception and study of components fabricated from several thousands of atoms. Academics, students and industrials rub shoulders here.

Giancarlo Faini
Director of the C2N
The conditions required to create these nano-objects are extreme so we must eliminate any dust. We must filter the level of dust, that's why we call it a cleanroom. That's one thing. The second one is the electromagnetic environment, or anything that can disturb our highly- sensitive fabrication instruments. And another formidable enemy is vibrations. That's why the cleanroom is entirely separate from the rest of the building. You can imagine that lithography means moving a beam in a highly precise fashion to be able to draw a tiny object on a surface, on our resin. Any electromagnetic disruption or vibration will deflect the beam by a few nanometers for example… which is a real problem for the objects we want to create.

Commentary – voice over
Delving into the heart of materials requires a considerable capacity of abstraction. On the nanometric scale, it is impossible for researchers to observe the result of their work to the naked eye. They must first imagine the component they want to create and prepare a recipe with basic materials and the instruments at their disposal. In these premises, physicists and research engineers attempt to develop the nanotechnology of the future. Components that could make information travel at extremely high speed, withstand extreme conditions and provide unique physical properties.

Laetitia Vincent
Physicist
Nanoscience is based on matter. Matter on a macroscopic scale is visible and it will have certain properties. When you reduce their size or shape, these nano-objects will display new characteristics and that's what we're trying to investigate in nanoscience. There are properties that we discover because we sculpt these materials and characterize them, and there are the features that we are actually searching for. One of the studies we are carrying out in our team, for example, aims to make the crystals grow on the nanometric scale to give them optical – and therefore light-producing – properties, which they don't have in another structure.

Commentary – voice over
To assemble and sculpt these new materials that could come into the composition of future lasers, researchers can rely on all the tools available in the cleanroom. Environmental parameters here are constantly assessed, as are accesses, since this research can actually prove quite sensitive, both in industrial and scientific terms.

It is in these rooms that researchers assemble matter, based on materials such as those used for microelectronics: silicon, arsenic, gallium. These machines, called growth chamber, allow to create flat or three dimensional structures from atoms sprayed on surfaces. Inside the equipment, absolute vacuum and cleanliness are the rule.

Laetitia Vincent
Physicist
In this machine here, we create deposits, meaning we make our crystals grow atom by atom. This machine is under vacuum. We place the sample here in an airlock and then we take it, always in ultrahigh vacuum, to avoid any contamination of the substrate, we take it to our dish over there. In this dish we inject gases. Since the substrate is heated, the gases will crack on the surface of the substrate and the atoms will come to stick, to be absorbed and form layer upon layer on the surface.

Commentary – voice over
Although many months are often necessary to reach the vacuum necessary to the smooth realization of the recipe, it only takes a few hours to fabricate the component. But how can the result of this “growth” of matter be observed?

Unlike most laboratories specialized in nanoscience, the C2N enables researchers to transport their samples within the same location throughout their various development stages. In these rooms, electronic microscopes make it possible to observe the components that have been sculpted.

These images taken at regular intervals show the growth of these new materials on the substrate. Slowly, the layers superimpose to create new structures that can later be modelled and enter the composition of new objects, visible to the naked eye this time.

These studies are still experimental but they will gradually shape the computers and communication tools of the future.

Giancarlo Faini
Director of the C2N
There's a complete synergy between technology, such as instrumentation, and science. In the cleanroom, the task of the engineer and that of the researcher are practically the same, but motivations are different. The scientist will promote the development of technology, and technology, thanks to increasingly precise instrumentation, will make science progress much faster. Being able to constantly refine instruments allows us to verify laws that we couldn't verify before or contradict them. To see things, on an experimental level, that debunk our beliefs.

Commentary – voice over
While the tools of the C2N can test quantum theories and observe physical properties of materials at the nanometric scale, they are also used in applied research with varied implications.

A team is interested in the use of nanotechnology for medical applications. For several years now, these researchers have attempted to find an innovative answer for patients suffering from respiratory failure. The goal is to develop a device capable of acting as an artificial lung. This team had to conceive a surface in a cleanroom that could simulate the flow of human blood through our pulmonary alveoli. Many tests were necessary to succeed in creating this circuit of capillaries engraved on a surface the size of a CD.

Julie Lachaux
Physicist
Thanks to microfluidics and micro-fabrication techniques, we are able here to create devices composed of micro channels in which blood circulates and micro channels in which oxygenation gas flows, whether air or pure oxygen. And between these two channels a thin membrane allows the exchange of gas, transferring oxygen to the blood and releasing carbon dioxide. So this performs the physiological function of a lung.

Here we can see that in three modules placed on top of one another, we have a blood circulation of 45ml per minute. Clinically, we need one liter per minute, so it would take about sixty such devices piled up to obtain a functional device for the human body.

Commentary – voice over
The research and innovation developed at the C2N in the field of nanoscience and nanotechnology are the foundation for upcoming technological breakthroughs, and maybe even real scientific revolutions. Advances in current communication channels is only the first step towards a potential industrial revolution.

Laetitia Vincent
Physicist
There are plenty of materials we don't know yet, and many configurations of material synthesis if we refer to the atomic structure. There are loads of different structures piled up on one another that we couldn't previously synthesize and will soon be able to. It's a new world; there are so many things to explore.

Commentary – voice over
The exploration of this nanoworld still faces numerous theoretical barriers that the tools found in cleanrooms can break down. These studies should also be made accessible to young researchers, by developing the training platform currently installed at the C2N.

These young scientists may be the ones who will sketch the outlines of the world of the future, by shaping this infinitely small, yet infinitely promising, realm.