# US 6,458,325 B1 · Apparatus for analyzing liquid samples automatically and continually > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,458,325 B1 - Document ID: US6458325B1 - Status: Granted - Kind: B1 - Application number: 08/976,393 - Filed: 1997-11-21 - Granted: 2002-10-01 - Earliest claimed: 1996-11-25 - Assignees: ABB AB - Inventors: Dietrich Roscher; Peter Heun; Holger Klingner; Norbert Gebert - Web page: https://patentgrep.com/patent/US6458325B1 ## CPC - F04B 43/046: {with piezoelectric drive} - B01J 19/0093: {Microreactors, e.g. miniaturised or microfabricated reactors (laboratory containers with capillary fluid transport in microfabricated channels or chambers B01L3/5027)} - B01L 3/502715: {characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces} - B01L 3/50273: {characterised by the means or forces applied to move the fluids} - B01F 33/30: Micromixers - B01J 2219/00828: Silicon wafers or plates - B01J 2219/00889: Mixing - B01J 2219/00891: Feeding or evacuation - B01L 2300/0654: Lenses; Optical fibres - B01L 2300/0816: Cards, e.g. flat sample carriers usually with flow in two horizontal directions - B01L 2300/0867: Multiple inlets and one sample wells, e.g. mixing, dilution - B01L 2400/0439: ultrasonic vibrations, vibrating piezo elements - Y10T 436/25: including sample preparation - Y10T 436/25625: Dilution - Y10T 436/2575: Volumetric liquid transfer - F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE - B01F: MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING (mixing paints B44D3/06) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An apparatus analyzes liquid samples automatically and continuously by mixing certain reagents within a common arrangement of membrane pumps, mixing chambers and connecting conduits formed in a silicon wafer and evaluating the reaction results with the help of suitable sensors on the silicon wafer, the silicon wafer being of 100 orientation and the structure thereof having been formed by anisotropic etching. Immediately before and after the pump chamber of trapezoidal cross section, there are conduits of a v-shaped or trapezoidal cross section which have a nonlinear flow resistance. ## Claims ### Claim 1 An apparatus for mixing liquid reagents thereby to cause a reaction in which the reagents react chemically and for analyzing, by means of a sensor, a sample of liquid resulting from the reaction, comprising: a substrate having a micropump including an inlet conduit and an outlet conduit etched in the substrate and a pumping chamber etched in the substrate and connected to the inlet conduit and the outlet conduit, the pumping chamber having a volume which expands and contracts during a complete pump cycle; said substrate having a mixing chamber etched thereon and connected to said outlet conduit; said inlet conduit having an effective flow cross section different from that of said outlet conduit such that over the complete pump cycle net fluid flow is from the inlet conduit and out the outlet conduit; and a covering layer covering said substrate to seal said pumping chamber, said inlet conduit, said outlet conduit and said mixing chamber; wherein said pumping chamber contracts and expands such that a flow in the inlet conduit is laminar entering said pumping chamber and turbulent exiting said pumping chamber and a flow in the outlet conduit is laminar both entering and exiting said pumping chamber. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the micropump includes said pumping chamber being rectangular with a trapezoidal cross section covered by said covering layer, a piezo element on said covering layer for changing a volume of said pumping chamber, and said inlet conduit and said outlet conduit have different flow resistances. ### Claim 3 (depends on 2) The apparatus of claim 2, further comprising a pressure measuring chamber connected via the outlet conduit with the micropump and via a measuring conduit with the mixing chamber, and a first pressure sensor coupled with said measuring chamber and a second pressure sensor coupled with said mixing chamber each supplying signals for determining a difference signal for a servo component of the micropump. ### Claim 4 (depends on 1, 2) The apparatus of claim 1 or 2, wherein multiple ones of said micropump are connected with the mixing chamber. ### Claim 5 (depends on 1, 2) The apparatus of claim 1 or 2, her comprising a reaction conduit disposed between the mixing chamber and an evaluating sensor. ### Claim 6 (depends on 1, 2) The apparatus of claim 1 or 2, wherein said substrate is a silicon wafer is embedded in a chip carrier and the liquid sample and the reagents are introduced into said substrate via said chip carrier. ### Claim 7 (depends on 3) The apparatus of claim 3, wherein in a carrier plate having elastic contacts covers said covering layer and said elastic contacts make electrical connection with said piezo element and the first and second pressure sensors. ### Claim 8 (depends on 1, 2) The apparatus of claim 1 or 2, wherein the covering layer is a glass covering layer and connected by an anodic bonding to the substrate. ### Claim 9 (depends on 8) The apparatus of claim 8, further comprising a light-emitting diode and a photoelement contacting on the glass covering layer and a cuvette duct is etched into the substrate beneath said light-emitting diode and said photoelement. ### Claim 10 (depends on 1) The apparatus of claim 1 wherein said substrate is a silicon wafer with a 100 orientation in its crystalline lattice structure and the etching of the silicon wafer is effected by anisotropic etching. ### Claim 11 An apparatus for mixing liquid reagents thereby to cause the reagents to react chemically and for analyzing by means of a sensor a sample of a liquid resulting from the reaction by means of a sensor, comprising: a substrate having a micropump with an inlet conduit and an outlet conduit etched thereon; said substrate having a mixing chamber etched thereon and connected to said outlet conduit; said substrate being closed off by a covering layer; said micropump having a pumping chamber covered by said covering layer and a piezo element on said covering layer for changing a volume of said pumping chamber; and said inlet conduit having an effective flow cross section different from that of said outlet conduit such that a flow in the inlet conduit is laminar entering said pumping chamber and turbulent exiting said pumping chamber and a flow in the outlet channel is laminar both entering and exiting said pumping chamber so that over a complete pump cycle net fluid flow is from the inlet conduit and out the outlet conduit. ### Claim 12 (depends on 1) The apparatus of claim 1, further comprising a pressure measuring chamber connected via the outlet conduit with the micropump and via a measuring conduit with the mixing chamber, and a first pressure sensor coupled with said measuring chamber and a second pressure sensor coupled with said mixing chamber each supplying signals for determining a difference signal for a servo component of the micropump.