Published in:

Physical Review Letters 91,5 (2003) 050402;


The first precise measurement of the Casimir force between dissimilar metals is reported. The attractive force, between a Cu layer evaporated on a microelectromechanical torsional oscillator and an Au layer deposited on an Al2O3 sphere, was measured dynamically with a noise level of 6 fN/rootHz. Measurements were performed for separations in the 0.2-2 mum range. The results agree to better than 1% in the 0.2-0.5 mum range with a theoretical model that takes into account the finite conductivity and roughness of the two metals. The observed discrepancies, which are much larger than the experimental precision, can be attributed to a lack of a complete characterization of the optical properties of the specific samples used in the experiment.


mu-m range;; dimensions;; solids

Date of this Version

January 2003



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