Presentation by Falko Schmidt on " Casimir-Lifshitz forces vs. Critical Casimir forces" at WE-Heraeus-Seminar

January 26, 2022

Falko Schmidt is presenting the latest research findings as part of the  WE-Heraeus-Seminar on fluctuation-induced force taken place from 14.-18.02.2022.
His presentation will be about "Casimir-Lifshitz forces vs. Critical Casimir forces: Trapping and releasing of flat metallic particles".

Abstract: Casimir forces in quantum electrodynamics are the well-known vacuum electromagnetic fluctuations occuring even at zero temperature. Their generalization at finite temperature and in material media are referred to as Casimir-Lifshitz forces.  These forces are typically attractive, leading to the widespread problem of stiction between the metallic parts of micro- and nanodevices.  Here, we experimentally demonstrate that repulsive critical Casimir forces, which emerge in a critical binary liquid mixture upon approaching the critical temperature, can be used to prevent stiction due to Casimir-Lifshitz forces. We show that critical Casimir forces can be  dynamically  tuned  via  temperature,  eventually overcoming Casimir-Lifshitz attraction.  By removing one of the key limitations to their deployment, this experimental demonstration can accelerate the development of micro- and nanodevices for a broad range of applications.

Time: 16.02.22 15:10-15:40 CET 
Place: Virtual
The distance between substrate and flake can be actively tuned via critical Casimir forces. Left: SEM image of the flakes. Middle: Illustration of experimental conditions on substrate functionality (red/blue). Right: Theoretical predictions of forces.