  We present a Casimir force setup based on an all-optical ferrule-top sensor.
We demonstrate that the instrument can be used to measure the gradient of the
Casimir force between a gold coated sphere and a gold coated plate with results
that are comparable to those achieved by similar atomic force microscope
experiments. Thanks to the monolithic design of the force sensor (which does
not require any optical triangulation readout) and to the absence of
electronics on the sensing head, the instrument represents a significant step
ahead for future studies of the Casimir effect under engineered conditions,
where the intervening medium or the environmental conditions might be
unsuitable for the use of more standard setups.
