# US 2023/0065652 A1 · Microfluidic device being capable of initiating sequential flow from multiple reservoirs > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0065652 A1 - Document ID: US20230065652A1 - Status: Published application - Kind: A1 - Application number: 17/894,240 - Filed: 2022-08-24 - Published: 2023-03-02 - Earliest claimed: 2021-08-25 - Assignees: Korea Institute of Machinery & Materials - Applicants: Korea Institute of Machinery & Materials - Inventors: Yeong-Eun YOO; Kwanoh KIM; Do Hyun KANG; Jaesung YOON - Web page: https://patentgrep.com/patent/US20230065652A1 ## CPC - B01L 3/502738: {characterised by integrated valves (throttle valves in microfluidic sample containers B01L3/502746)} - 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} - B01L 3/527: {for a plurality of reagents} - B01L 2300/049: Valves integrated in closure - B01L 2300/0681: Filter - B01L 2400/049: vacuum - B01L 2400/0616: Ball valves - B01L 2400/082: Active control of flow resistance, e.g. flow controllers - B01L 2400/084: Passive control of flow resistance - B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE ## Abstract The microfluidic device capable of initiating sequential flow according to the present invention includes: a main flow path in which a suction port for sucking the fluid with a negative pressure is formed at one end; a plurality of reservoirs that supply a fluid stored therein to the main flow path through an outlet by the negative pressure applied to the suction port, and are connected to a plurality of different points of the main flow path; and a blocking element that blocks the inflow of external air to the main flow path through the outlet when all the fluid in the reservoir flows out, wherein the fluid stored in a plurality of the reservoirs may flow sequentially. ## Claims ### Claim 1 A microfluidic device capable of initiating sequential flow, comprising: a main flow path in which a suction port for sucking the fluid with a negative pressure is formed at one end; a plurality of reservoirs that supply a fluid stored therein to the main flow path through an outlet by the negative pressure applied to the suction port, and are connected to a plurality of different points of the main flow path; and a blocking element that blocks the inflow of external air to the main flow path through the outlet when all the fluid in the reservoir flows out, wherein the fluid stored in a plurality of the reservoirs flows sequentially. ### Claim 2 (depends on 1) The microfluidic device capable of initiating sequential flow of claim 1, wherein a reaction chamber is formed in the middle of the main flow path between the suction port and a first point where the reservoir is connected closest to the main flow path from the suction port to mix and react the fluid. ### Claim 3 (depends on 1) The microfluidic device capable of initiating sequential flow of claim 1, wherein a membrane is formed in a middle portion of the main flow path between a first point where the reservoir is connected closest to the main flow path from the suction port and the suction port. ### Claim 4 (depends on 1) The microfluidic device capable of initiating sequential flow of claim 1, wherein the main flow path has different flow resistance depending on a distance from the suction port. ### Claim 5 (depends on 4) The microfluidic device capable of initiating sequential flow of claim 4, wherein in the main flow path, flow resistance of a partial flow path between two adjacent points where the reservoirs are connected is formed differently. ### Claim 6 (depends on 5) The microfluidic device capable of initiating sequential flow of claim 5, wherein the main flow path decreases the flow resistance by increasing the size of the partial flow path or shortening a length of the partial flow path as the distance from the suction port increases. ### Claim 7 (depends on 1) The microfluidic device capable of initiating sequential flow of claim 1, wherein the main flow path controls the flow of the fluid by connecting a partial flow path between two points where the reservoirs are connected with a plurality of microfluidic paths. ### Claim 8 (depends on 1) The microfluidic device capable of initiating sequential flow of claim 1, wherein the connecting flow path connecting the outlet of the reservoir and the main flow path is formed such that the size of the flow path is gradually increased or decreased. ### Claim 9 (depends on 1) The microfluidic device capable of initiating sequential flow of claim 1, wherein the connecting flow path connecting the outlet of the reservoir and the main flow path is formed to protrude into the reservoir. ### Claim 10 (depends on 1) The microfluidic device capable of initiating sequential flow of claim 1, wherein the reservoir is formed above the main flow path and supplies fluid vertically downward to the main flow path. ### Claim 11 (depends on 1) The microfluidic device capable of initiating sequential flow of claim 1, wherein the reservoir is formed on one side of the main flow path to horizontally supply fluid to the main flow path. ### Claim 12 (depends on 1) The microfluidic device capable of initiating sequential flow of claim 1, wherein the blocking element includes a blocking bead that floats on the fluid in the reservoir and descends as the fluid flows out through the outlet to block the outlet. ### Claim 13 (depends on 1) The microfluidic device capable of initiating sequential flow of claim 1, wherein the blocking element includes a blocking cover that closes an open top of the reservoir and is formed of a material with elasticity, and contracts toward the outlet after the fluid flows out through the outlet and blocks air inflow to the main flow path. ### Claim 14 (depends on 1) The microfluidic device capable of initiating sequential flow of claim 1, wherein the blocking element is formed with a valve that blocks the outlet or blocks the reservoir from the outside, and the valve operates automatically by a control signal or manually. ### Claim 15 (depends on 1) The microfluidic device capable of initiating sequential flow of claim 1, wherein the main flow path is formed to increase or decrease a size of the flow path locally to control the flow characteristic. ### Claim 16 (depends on 1) The microfluidic device capable of initiating sequential flow of claim 1, wherein a step is formed in the main flow path to increase or decrease a size of the flow path to thereby control the flow characteristics. ### Claim 17 (depends on 1) The microfluidic device capable of initiating sequential flow of claim 1, wherein a plurality of reservoirs are connected to a single point on the main flow path. ### Claim 18 (depends on 1) The microfluidic device capable of initiating sequential flow of claim 1, wherein one end of the main flow path is branched to form a plurality of suction ports.