Precise Determination of the Casimir Force and First Realization of a a 'Casimir Less' Experiment

We present improved Casimir effect measurements. The attractive force between a metallized sphere and the coated plate of a Si microelectromechanical oscillator is measured with unparalleled precision. The same setup, but in a dynamic scheme, yields a determination of the Casimir pressure between two infinite plates. Since the Casimir force is the dominant interaction in the 0.1-1mum range under these experimental conditions, it acts as a background in the search for new forces in the submicrometer range. We report our progress in the realization of an expriment where the effect of the Casimir force is minimized (a "Casimir-less" configuration).