# US 8,539,823 B2 · Microfluidic device and method of loading sample into the microfluidic device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,539,823 B2 - Document ID: US8539823B2 - Status: Granted - Kind: B2 - Application number: 12/546,302 - Filed: 2009-08-24 - Published: 2010-03-04 - Granted: 2013-09-24 - Earliest claimed: 2008-09-02 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Beom-seok Lee - Inventors: Beom-seok Lee - Web page: https://patentgrep.com/patent/US8539823B2 ## CPC - G01N 35/00029: {provided with flat sample substrates, e.g. slides (G01N35/028 takes precedence)} - G01N 2035/00039: {Transport arrangements specific to flat sample substrates, e.g. pusher blade} - G01N 2035/00495: {Centrifuges} - Y10T 137/206: Flow affected by fluid contact, energy field or coanda effect [e.g., pure fluid device or system] - Y10T 137/2224: Structure of body of device - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Provided is a microfluidic device. The microfluidic device includes a sample chamber in which a sample is accommodated. The sample chamber includes: an introduction portion including a loading hole through which the sample is loaded; an accommodation portion including a discharge hole; and a neck portion forming a boundary between the introduction portion and the accommodation portion. The neck portion provides a capillary pressure for controlling flow of the sample between the introduction portion and the accommodation portion. ## Claims ### Claim 1 A microfluidic device comprising: a sample chamber in which a sample is accommodated, wherein the sample chamber comprises: an introduction portion comprising a loading hole through which the sample is loaded; an accommodation portion comprising a discharge hole; and a neck portion which forms a boundary between the introduction portion and the accommodation portion and provides a capillary pressure for controlling flow of the sample between the introduction portion and the accommodation portion, wherein a bottom surface of the introduction portion is inclined upward to the neck portion from the loading hole to prevent flowing backward of the sample, and wherein a distance from a center of the microfluidic device to a sidewall of the sample chamber gradually increases from the neck portion to the discharge hole. ### Claim 2 (depends on 1) The microfluidic device of claim 1, wherein the sample chamber further comprises a distance maintaining portion which maintains a distance between a front end part of a sample loader inserted in the loading hole and a bottom surface of the introduction portion, and the distance maintaining portion is disposed in the introduction portion. ### Claim 3 (depends on 1) The microfluidic device of claim 1, wherein the sample chamber further comprises a backward flow prevention portion which protrudes from a bottom surface of the accommodation portion. ### Claim 4 (depends on 3) The microfluidic device of claim 3, wherein the backward flow prevention portion is disposed in a direction that crosses a direction of a flow path of a sample flowing to the discharge hole. ### Claim 5 (depends on 4) The microfluidic device of claim 4, wherein an end part of the backward flow prevention portions is inclined upward toward the discharge hole. ### Claim 6 (depends on 1) The microfluidic device of claim 1, further comprising an analysis unit which is connected to the discharge hole of the accommodation portion, receives the sample accommodated in the sample chamber and analyzes the sample. ### Claim 7 (depends on 6) The microfluidic device of claim 6, wherein the analysis unit comprises: a sample measuring portion which is connected to the sample chamber and measures the sample; and a sample detection chamber which is connected to the sample measuring portion and in which a portion of the sample exceeding a capacity of the sample measuring portion is accommodated. ### Claim 8 (depends on 7) The microfluidic device of claim 7, wherein the analysis unit further comprises a surplus sample chamber which is connected to the sample detection chamber and in which a portion of the sample exceeding a capacity of the sample detection chamber is accommodated. ### Claim 9 (depends on 7) The microfluidic device of claim 7, wherein the sample measuring portion separates the sample into a supernatant and a sedimentation material by a centrifugal force. ### Claim 10 (depends on 9) The microfluidic device of claim 9, wherein the analysis unit further comprises: a dilution chamber in which a dilution buffer is accommodated, which is connected to the sample measuring portion and to which the supernatant is supplied; and a detection chamber in which a reagent is accommodated and to which a mixture of the supernatant and the dilution buffer is supplied from the dilution chamber. ### Claim 11 (depends on 10) The microfluidic device of claim 10, wherein the analysis unit further comprises a measuring chamber which is disposed between the dilution chamber and the sample measuring portion and accommodates a fixed amount of the supernatant. ### Claim 12 (depends on 11) The microfluidic device of claim 11, wherein the analysis unit further comprises a plurality of valves disposed in channels connecting the sample measuring portion, the measuring chamber, the dilution chamber, and the detection chamber, to control a flow of a fluid. ### Claim 13 A microfluidic device comprising: a sample chamber in which a sample is accommodated, wherein the sample chamber comprises an introduction portion comprising a loading hole through which the sample is loaded, and a neck portion which provides a capillary pressure for controlling flow of the sample between the introduction portion and the accommodation portion, wherein a bottom surface of the introduction portion is inclined upward to the neck portion from the loading hole to prevent flowing backward of the sample, and wherein a distance from a center of the microfluidic device to a sidewall of the sample chamber gradually increases from the neck portion to the discharge hole; and an analysis unit which receives and analyzes the sample from the sample chamber, wherein the analysis unit comprises: a sample measuring portion which measures the sample; and a sample detection chamber which is connected to the sample measuring portion and in which a portion of the sample exceeding a capacity of the sample measuring portion is accommodated; and a surplus sample chamber which is connected to the sample detection chamber and in which a portion of the sample exceeding a capacity of the sample detection chamber is accommodated. ### Claim 14 (depends on 13) The microfluidic device of claim 13, wherein the sample chamber further comprises an accommodation portion comprising a discharge hole, wherein the neck portion forms a boundary between the introduction portion and the accommodation portion. ### Claim 15 (depends on 14) The microfluidic device of claim 14, wherein the sample measuring portion separates the sample into a supernatant and a sedimentation material by a centrifugal force. ### Claim 16 (depends on 15) The microfluidic device of claim 15, wherein the analysis unit further comprises: a dilution chamber in which a dilution buffer is accommodated, which is connected to the sample measuring portion and to which the supernatant is supplied; and a detection chamber in which a reagent is accommodated and to which a mixture of the supernatant and the dilution buffer is supplied from the dilution chamber. ### Claim 17 (depends on 16) The microfluidic device of claim 16, wherein the analysis unit further comprises a measuring chamber which is disposed between the dilution chamber and the sample measuring portion and accommodates a fixed amount of the supernatant. ### Claim 18 (depends on 17) The microfluidic device of claim 17, wherein the analysis unit further comprises a plurality of valves disposed in channels connecting the sample measuring portion, the measuring chamber, the dilution chamber, and the detection chamber, to control a flow of a fluid. ### Claim 19 A microfluidic device comprising: a sample chamber in which a sample is accommodated; and an analysis unit which receives the sample from the sample chamber and comprises at least one reaction chamber for analyzing the sample, wherein the sample chamber comprises: a loading hole through which the sample is loaded; a discharge hole which is connected to the analysis unit; and a neck portion comprising a capillary valve which is disposed between the loading hole and the discharge hole and passes the sample only when a predetermined pressure is applied to the sample, wherein the capillary valve comprises a protrusion formed by first and second inclined portions of a bottom surface of the sample chamber, and wherein a distance from the center of the microfluidic device to a sidewall of the sample chamber gradually increases from the neck portion to the discharge hole. ### Claim 20 (depends on 19) The microfluidic device according to claim 19, wherein the sample chamber further comprises at least one backward flow prevention portion which protrudes from the bottom surface of the sample chamber at a position between the capillary valve and the discharge hole, and provides a flow resistance to the sample to impede the sample from flowing back towards the loading hole.