Actuator coupling system and a pipetting module comprising such a coupling system

A pipetting module comprising:

• (a) a micromachined pipetting device for pipetting liquid volumes in the submicroliter and microliter range, said micromachined pipetting device including a membrane having a central zone, the central zone of said membrane being displaced by a macroactuator,
• (b) a macroactuator which has an upper end and a lower end for displacing said membrane, and
• (c) means for mechanically coupling said macroactuator to said membrane of said micromachined pipetting device, said coupling means comprising
• (d) a first body for holding the macroactuator, said first body having a side wall having an outer surface and a bottom having an outer surface,
• (e) the macroactuator is mechanically mounted on said first body,
• (f) a second body having an upper outer surface, a lower outer surface, and a bore for receiving said first body, the size of said bore and the size of said first body being such that the outer surface of the side wall of the first body snugly fits within said bore,
• (g) a screw arrangement for fixing the axial position of said first body within said bore, the screw arrangement comprising
• (i) a first bolt segment and a second bolt segment, said bolt segments being located within said second body and said bolt segments each having a side wall with the same radius of curvature as a closed line defined by a cross-section of said bore of said second body and
• (ii) a screw passing through one of the bolt segments and being connectable to the other bolt segment by a screw connection, said screw connection enabling said bolt segments to be pulled against each other in order to reduce the size of a gap existing between said bolt segments and thereby reducing the space available for said first body in said bore of said second body, and
• (h) a plate arrangement for mounting said micromachined device on said second body in such a way that the upper end of the macroactuator exerts a predetermined force or pressure on said membrane of said micromachined device.