# US 2009/0260692 A1 · Autonomous electrochemical actuation of microfluidic circuits > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2009/0260692 A1 - Document ID: US20090260692A1 - Status: Published application - Kind: A1 - Application number: 12/349,365 - Filed: 2009-01-06 - Published: 2009-10-22 - Earliest claimed: 2008-01-11 - Assignees: California Institute of Technology - Inventors: Sameer WALAVALKAR; Axel Scherer - Web page: https://patentgrep.com/patent/US20090260692A1 ## CPC - F04B 19/006: {Micropumps (F04B43/043 and F04B43/095 take precedence)} - B01L 3/50273: {characterised by the means or forces applied to move the fluids} - B01L 2300/0816: Cards, e.g. flat sample carriers usually with flow in two horizontal directions - B01L 2300/0874: Three dimensional network - B01L 2300/10: Means to control humidity and/or other gases - B01L 2300/1827: using resistive heater - B01L 2400/0421: electrophoretic flow - B01L 2400/046: Chemical or electrochemical formation of bubbles - Y10T 29/494: Fluidic or fluid actuated device making - Y10T 29/49826: Assembling or joining - Y10T 137/0391: Affecting flow by the addition of material or energy - Y10T 137/2191: By non-fluid energy field affecting input [e.g., transducer] - Y10T 137/2213: Electrically-actuated element [e.g., electro-mechanical transducer] - Y10T 137/2224: Structure of body of device - 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) - B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A microfluidic structure with an electrically controlled pressure source is shown. The pressure source is an electrolyte connected with electrodes. Dissociation of the electrolyte generates the pressure, which is used to obtain a valve-like or pump-like behavior inside the microfluidic structure. A process for manufacturing the microfluidic structure and a method to circulate fluids in a microfluidic channel are also described. ## Claims ### Claim 1 A microfluidic structure comprising: control layers comprising control channels; fluidic layers comprising microfluidic channels, the microfluidic channels adapted to be controlled by the control channels; and a pressure source comprising an electrolyte adapted to be electrolitically dissociated in one or more fluids, the pressure source fluidically connected with at least one control channel, wherein, upon electrolytic dissociation of the electrolyte, the one or more fluids travel along the at least one control channel to control the microfluidic channels. ### Claim 2 (depends on 1) The microfluidic structure of claim 1, wherein the pressure source further comprises electrodes connected with the electrolyte, dissociation of the electrolyte in the one or more fluids occurring upon generation of current in the electrodes. ### Claim 3 (depends on 1) The microfluidic structure of claim 1, wherein the one or more fluids are gases. ### Claim 4 (depends on 1) The microfluidic structure of claim 1, wherein the electrolyte is water and the one or more fluids are oxygen and hydrogen. ### Claim 5 (depends on 1) The microfluidic structure of claim 1, wherein the electrolyte is sodium sulfate and the one or more fluids are oxygen. ### Claim 6 (depends on 1) The microfluidic structure of claim 1, wherein control of the microfluidic channels by the one or more fluids travelling along the at least one control channel occurs through movement of membrane regions separating the control channels from the microfluidic channels. ### Claim 7 (depends on 1) The microfluidic structure of claim 1, wherein the pressure source is located in a chamber fluidically connected with the at least one control channel. ### Claim 8 (depends on 1) The microfluidic structure of claim 1, further comprising: a further pressure source comprising a further fluid wherein, upon the electrolytic dissociation of the electrolyte, the one or more fluids exercise pressure on the further fluid which, in turn, generates a pumping effect on the microfluidic channels. ### Claim 9 (depends on 8) The microfluidic structure of claim 8, wherein the further pressure source is located in a microfluidic channel, the microfluidic channel fluidically connected with the control channel in which the one or more fluids are adapted to travel upon the electrolytic dissociation of the electrolyte. ### Claim 10 (depends on 8) The microfluidic structure of claim 8, further comprising a mirror pressure source and a further mirror pressure source, the combination of the pressure source, further pressure source, mirror pressure source and further mirror pressure source adapted to provide the microfluidic structure with a bidirectional pumping effect. ### Claim 11 A process for manufacturing a microfluidic structure containing a pressure source, comprising: forming electrodes; forming microfluidic chambers and microfluidic channels; positioning the electrodes in a microfluidic chamber of the formed microfluidic chambers; locating an electrolyte in the microfluidic chamber, the electrolyte contacting the electrodes and acting as a pressure source upon dissociation of the electrolyte into one or more fluids when current passes through the electrodes; and connecting the microfluidic chamber with at least one microfluidic channel of the microfluidic channels. ### Claim 12 (depends on 11) The process of claim 11, wherein the microfluidic chamber is connected with the at least one microfluidic chamber of the microfluidic chambers in a valve arrangement. ### Claim 13 (depends on 11) The process of claim 11, wherein the microfluidic chamber is connected with the at least one microfluidic chamber of the microfluidic chambers in a pumping arrangement. ### Claim 14 A method to circulate at least one between oxygen and hydrogen in a microfluidic channel, comprising: locating electrically controlled water inside a chamber of a microfluidic circuit comprising the microfluidic channel; fluidically connecting the chamber with the microfluidic channel; and electrolitically dissociating the water into oxygen and hydrogen, whereby at least one of oxygen and hydrogen circulates in the microfluidic channel. ### Claim 15 (depends on 14) The method of claim 14, wherein hydrogen is separated from oxygen. ### Claim 16 (depends on 15) The method of claim 15, wherein the at least one of hydrogen and oxygen circulating in the microfluidic channel is hydrogen. ### Claim 17 (depends on 14) The method of claim 14, wherein the electrically controlled water comprises electrodes contacting the water. ### Claim 18 (depends on 14) The method of claim 14, wherein the at least one of oxygen and hydrogen circulates in the microfluidic channel to control fluid circulation. ### Claim 19 (depends on 18) The method of claim 18, wherein control occurs in a valve-like behavior. ### Claim 20 (depends on 18) The method of claim 18, wherein control occurs in a pump-like behavior.