The present invention relates to a device comprising a substrate 5, a transmission source 1 emitting an acoustic beam from the first face 7 of the substrate 5 toward the second side 6 of the substrate 5, the first reflecting means 11 arranged such that beam has after reflection a substantially parallel propagation direction to the second face 6 and through an area of study 3, and second reflecting means 12 for reflecting the beam after passing through the study 3 towards the area first side 7 to a receiver 10. the invention relates to the field of bioMEMS and laboratories on a chip. The invention enables in particular to leave free one side of the substrate 5 for example, an observation of the study area 3 in parallel with an optical microscope. In addition, the invention facilitates performing focusing or divergence elements (lenses) or reflective (mirror) of the acoustic beam.