Fraunhofer-gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Other

Peter Woias

Martin Richter

Stefan Kluge

Reinhard Linnemann

Bernd Hillerich

A liquid reservoir with level measurement includes a base body () and a channel () implemented in the base body and comprising an inlet () and an outlet (), the dimensions of the cross-section of the channel being selected such that a liquid () which may be filled into the channel forms a liquid meniscus () which demarcates a section () of the channel which is filled with liquid from an unfilled section () of the channel in which no liquid is present, the position of the meniscus in relation to the channel being substantially independent of the orientation of the liquid reservoir. The liquid reservoir further includes detection means () for detecting the position of the liquid meniscus and/or the channel so as to obtain, from the position of the liquid meniscus, the level and/or a change in the level of the liquid reservoir. The inventive liquid reservoir is suitable as a low-priced drug reservoir particularly in connection with a capacitive level detection.

Fluid reservoir with level measurement and a dosing system, a withdrawal system and a combined dosing/withdrawal system

A micromechanical transmission measuring cell serves to determine an optical absorption of a sample fluid or as a reactor for carrying out an optically detectable chemical reaction. The micromechanical transmission measuring cell comprises a receptacle ( ) used for holding the sample fluid, a light passage opening ( ) for introducing the light into the receptacle ( ), and a reflector ( ) directing the light relative to the receptacle ( ) in such a way that most of said light ( ) passes through said receptacle ( ) without multiple reflections on a wall of said receptacle ( ), and that the optical absorption of the sample fluid is detectable on the basis of the light passing through said receptacle without multiple reflections.

Micromechanical transmission measuring cell

A method of producing a pump body having an inlet opening provided with an inlet valve ( ) and an outlet opening provided with an outlet valve ( ), said method comprising as a first step the step of structuring a respective first main surface of a first and of a second semiconductor disc ( ) for defining a valve flap structure ( ) of the inlet valve and a valve seat structure ( ) of the outlet valve in the first disc and a valve flap structure of the outlet valve and a valve seat structure of the inlet valve in the second disc. Following this, a valve flap well structure ( ) and a valve opening well structure ( ) are formed in a predetermined relationship with the valve flap structures and the valve seat structures in a respective second main surface of the first and of the second semiconductor disc. The first main surfaces of said first and second semiconductor discs are connected in such a way that the respective valve flap structure is arranged in a predetermined relationship with a respective valve seat structure. Finally, the respective second main surface of said first and of said second semiconductor disc is etched at least in the area of the valve flap well structure and of the valve opening well structure so as to expose the valve flaps and open the valve seats.

Method for producing a micromembrane pump body

A micromechanically produced flow-restriction device has a first passage opening formed in a first main surface of a substrate. A channel is formed in a second main surface of the substrate and one end thereof is in fluid communication with the first passage opening. A second passage opening is in fluid communication with a second end of the channel. The first passage opening, the channel and the second passage opening define a flow path. A membrane is formed in the substrate and is in fluid communication with the first passage opening. A membrane electrode is formed at least on the membrane. A cover is attached to the second main surface of the substrate in such a way that the cover defines together with the channel a flow resistance of the flow-restriction device, the cover being provided with a counterelectrode which is arranged in opposed, spaced relationship with the membrane electrode in such a way that the membrane electrode and the counterelectrode define a capacitive pressure sensor, the capacitive pressure sensor being arranged on a wall of the flow path.

Micromechanically produced flow-restriction device

A micromembrane pump comprises a pump membrane which is adapted to be moved to a first and a second position with the aid of a drive means and a pump body connected to the pump membrane so as to define a pump chamber between these two components, the pump body being defined by two semiconductor plates having each formed therein a valve seat and a valve flap which are formed integrally with the respective semiconductor plate, the two semiconductor plates being connected in such a way that a respective passive non-return valve is defined by a valve seat of one semiconductor plate and by a valve flap of the other semiconductor plate, one of the passive non-return valves being arranged in an inlet opening penetrating both semiconductor plates, whereas the other of the non-return valves is arranged in an outlet opening penetrating both semiconductor plates. The pump membrane increases the volume of the pump chamber by a stroke volume when moving from the first to the second position and reduces the volume of the pump chamber by this stroke volume when moving from the second to the first position. According to the present invention, the ratio &egr; of the stroke volume to the volume of the pump chamber satisfies the following equation, when the pump membrane is at the first position:

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München, Germany

Peter Woias