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Mohideen and Roy measured the Casimir force with an atomic force microscope between a metallized sphere 196 micrometres across and a flat plate, at separations from 0.1 to 0.9 micrometres. They calibrated cantilever stiffness electrostatically and corrected the measured signal for residual contact potential, scattered light and changing surface separation. Their comparison averaged 26 scans at different plate locations and included finite conductivity, surface roughness and temperature corrections. The reported root-mean-square difference from the corrected theory was 1.6 piconewtons, corresponding to one percent at the smallest separation. Without those corrections the difference was 6.3 piconewtons. The authors describe the measured agreement as consistent with the conductivity and roughness corrections; their proposed further improvement in precision remained future work.

Precision Measurement of the Casimir Force from 0.1 to 0.9 μm