Tecan Trading Ag

Werner H&auml;lg

Nikolaus Ingenhoven

Stefano Fornito

Noa Schmid

Agathe Hodac

Mario Benedetti

The ejection orifice ( ) of a micropump including a baseplate ( ) of glass and a cover plate ( ) of silicon and intended for ejecting small liquid drops, has a diameter of about 50 &mgr;m, and is located in the center of a flat front surface ( ) which, in order to avoid accumulations of liquid in the region of the ejection orifice ( ), is only 8 times the area thereof and, along a continuous circular edge, is adjacent a lateral surface ( ) in the form of an envelope of truncated cone. The front surface ( ) and the lateral surface ( ) have a surface roughness of not more than N4 and are provided, for example, with a hydrophobic plasma polymer coating.

Micropump

A delivery apparatus has, in a housing ( ), a cannula ( ) whose rear end is connected to a diluter ( ) via a connecting tube ( ). A piezoelectric actuator ( ) increases in length under the action of a control signal and acts on a membrane ( ) pierced by the cannula tip ( ) and belonging to an interchangeable polypropylene pipette tip mounted on the delivery apparatus and adhering to the housing ( ) by means of a collar ( ) resting against said housing, and causing said membrane to sag, with the result that a drop of a sample liquid which was previously sucked in by means of the diluter ( ) and whose accurately adjustable volume is between 1 nl and 1 &mgr;l is ejected from an outlet orifice ( ). After a pipetting process the pipette tip is ejected by means of a slide ( ). If the level of the sample liquid in the pipette tip always remains below the cannula tip ( ), virtually no carry-over occurs.

Growing community of inventors

Männedorf, Switzerland

Werner Hälg

Growing community of inventors

Männedorf, Switzerland

Werner H&auml;lg

Werner Hälg