Unanswered questions about the application of Casimir forces
DOI: 10.1063/10.0002106
Unanswered questions about the application of Casimir forces lead image
Casimir forces – generated between uncharged bodies due to quantum fluctuations of the electromagnetic field – are attracting interest for their possible applications. In this perspective, Palasantzas et al. discuss the potential of utilizing Casimir forces in micro and nanosystems and provide three prospective directions.
The repulsive force generated by the effect could be promising for certain applications, but is difficult to achieve in practice due to material restrictions. Therefore, the authors focused the discussion on two potential applications they considered to be more feasible: actuation in electromechanical systems and adhesion between rough surfaces.
The authors present recent developments and unanswered questions regarding actuation and adhesion applications. While Casimir forces already play a role in adhesion in both natural and artificial systems, they also contribute to undesired stiction and can benefit from a better understanding of the effect. The authors describe experiments that may help to answer questions regarding the distance upon contact and the relative area of real contact, two qualities that control adhesion.
In a phase change material, the switching between amorphous and crystalline states could generate enough force contrast for actuation due to Casimir forces, which may have applications in micro/nanoelectromechanical systems (MEMS/NEMs). However, the authors believe that the practical application of Casimir forces will require a more thorough investigation of the effect from protective capping layers and volume compression.
“This is a perspective article that reviews some topics and underlines some open questions and directions that might be helpful to other researchers,” said author George Palasantzas.
Source: “Applications of casimir forces: Nanoscale actuation and adhesion,” by George Palasantzas, Mehdi Sedighi, and Vitaly B. Svetovoy, Applied Physics Letters (2020). The article can be accessed at https://doi.org/10.1063/5.0023150 .
