Skip to ContentSkip to Navigation
About usNews and EventsNews articles

Contact mode Casimir and capillary force measurements

14 January 2011

PhD ceremony: Mr. P.J. van Zwol, 14.45 uur, Academiegebouw, Broerstraat 5, Groningen

Title: Contact mode Casimir and capillary force measurements

Promotor(s): prof. T.T.M. Palstra

Faculty: Mathematics and Natural Sciences


The Casimir effect is said to be a “force from nothing”. Like the Lamb-Shift it is a consequence of the Heisenberg uncertainty principle for energy and time. Therefore the Casimir effect is fundamentally important. But it is also a background force in the search for new forces at microscopically small distances. The force becomes strong for nanoscale separations and affects the motion of parts in mechanical nanodevices, which is the reason that this thesis is written. Here the typical strength of the Casimir force for such systems was measured with an Atomic Force Microscope. Theory and experiments to probe the effect off roughness and optical reflectance on the force are discussed. The results of this analysis are not only important for nanodevices but also for theory that accurately describes the force for real materials. On the other hand the Casimir force may also be put to good use. For example in this thesis it is shown that the force can be modulated using switchable materials that are typically used in DVDs. In some special cases, when a fluid replaces the vacuum, the Casimir force can be made repulsive. A way of maximizing this repulsion is presented here. Casimir repulsion can be important for lowering friction between surfaces as it prevents them from touching.



Last modified:15 September 2017 3.41 p.m.

More news

  • 23 April 2019

    From paperclip to patent

    How is it possible that an albatross doesn’t crash and die when it lands? And how come its large wings don’t break due to air resistance? That is what you would expect, according to the laws of aerodynamics. However, Professor Eize Stamhuis has discovered...

  • 17 April 2019

    Why lightning often strikes twice

    In contrast to popular belief, lightning often does strike twice, but the reason why a lightning channel is ‘reused’ has remained a mystery. Now, an international research team led by the University of Groningen has used the LOFAR radio telescope to...

  • 16 April 2019

    Still going strong after four decades

    On March 29th professor of Applied Physics Jeff de Hosson was offered a farewell symposium, a few months after his official retirement date near the close of 2018. ‘But 29 March was the 100th birthday of Jan Francken, my predecessor.’ Besides, De Hosson...