Abstract: A volume sensor-free microdosing device comprises a pressure chamber which is at least partly delimited by a displacer, an actuating device for actuating the displacer, the volume of the pressure chamber being adapted to the changed by actuating the displacer, a media reservoir which is in fluid communication with the pressure chamber, an outlet opening which is in fluid communication with the pressure chamber, and a control mechanism.

Abstract: A fluid pump has a pump body and a displacer which is adapted to be positioned at a first and at a second end position by means of a drive, the displacer and the pump body being implemented such that a pump chamber is defined therebetween, and the pump chamber being adapted to be fluid-connected to an inlet and to an outlet via a first opening and a second opening which are not provided with check valves. An elastic buffer bordering on the pump chamber is provided. The displacer is implemented in the form of a plate which is secured to the pump body, and the pump body is provided with a recess defining the pump chamber. The drive acts on the displacer substantially in the area of the first opening. The displacer closes the first opening when it occupies its first end position and leaves the first opening free when it occupies its second end position.