Scientists from the Friedrich Schiller University of Jena, together with colleagues from Düsseldorf, Gothenburg, Lyngby and Trieste, have developed a clever way to separate nano-components.
Their idea is to add nano-components to the solvent close to its essential point. In the experimental setup, they managed to separate the materials in a controlled way just by changing the temperature of the solvent. The authors presented their successful experiment in the scientific journal “Nature Physics”.
Separate applications are critical areas of the solution
“We were looking for a solution to eliminate the unnecessary friction of the components of the nano-electromechanical system (NEMS) rubbing against each other,” said Dr. Falko Schmidt from the Institute of Applied Physics at the University of Jena says. This friction is called static stiction – a combination of the words static and friction – caused by the so-called quantum electrodynamic Casimir Force. These forces are the result of inevitable changes that cause the elements to join together. The researchers developed a method to change this effect by putting the materials in a very important solution – a mixture of water and oil – in which the change also occurs. The intensity of these changes can be directly controlled by changing the temperature.
Falko Schmidt explains, “The thing here is that we don’t remove the first revolutions, but replace them with stronger ones.” The desired effect was achieved in the experiment by using a light microscope objective. The researchers were able to hold gold nanoflakes on the surface of the structured metal. Normally the gold flake will stick to the seed. When the surrounding fluid approaches a critical point – the temperature difference between water and oil – the changes are so strong that friction is avoided. The research team concluded that this could be so effective that the glued parts could be separated and made to stick again.
A long way to solve an obvious problem
Dr. Falko Schmidt conducted these experiments while still at the University of Gothenburg, where he developed a new experimental method (A clever way to separate nano-components) that eventually led to his success. “We came up with the idea for this project early on, because this problem is well-known in nano-fabrication,” Schmidt said. However, the solution is long. It is a technique to control the Casimir effect from the quantum electrodynamic Casimir effect that finally wins.
The goal is to apply in the future the concept of freeing micro and nanoelectromechanical systems from restrictions due to mechanical friction, thus allowing the development of more efficient and functional nanocomponents.
