# US 9,752,904 B2 · Arrangement for providing information on fluid flow rate > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,752,904 B2 - Document ID: US9752904B2 - Status: Granted - Kind: B2 - Application number: 15/159,221 - Filed: 2016-05-19 - Published: 2016-12-01 - Granted: 2017-09-05 - Earliest claimed: 2015-05-29 - Assignees: Stichting IMEC Nederland - Applicants: Stichting IMEC Nederland - Inventors: Marcel Arie Günther Zevenbergen; Rajesh Mandamparambil; Chuan Nie; Arnoldus Joannes Hubertus Frijns; Jacob Marinus Jan Den Toonder - Web page: https://patentgrep.com/patent/US9752904B2 ## CPC - G01F 1/00: Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow (measuring a proportion of the volume flow G01F5/00) - B01L 3/5027: {by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip} - B01L 3/502723: {characterised by venting arrangements} - B01L 2200/0605: Metering of fluids - B01L 2200/0621: Control of the sequence of chambers filled or emptied - B01L 2200/0678: Facilitating or initiating evaporation - B01L 2300/048: enabling gas exchange, e.g. vents - B01L 2300/069: Absorbents; Gels to retain a fluid - B01L 2300/0816: Cards, e.g. flat sample carriers usually with flow in two horizontal directions - B01L 2300/0864: comprising only one inlet and multiple receiving wells, e.g. for separation, splitting - B01L 2300/0883: Serpentine channels - B01L 2300/0887: Laminated structure - B01L 2400/0487: fluid pressure, pneumatics - G01F 1/68: by using thermal effects - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME - B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE ## Abstract The present disclosure relates to an arrangement for providing information about a flow rate of a fluid, comprising: a fluid inlet opening, at least one flow channel, and at least one porous zone located above the at least one flow channel, wherein the surface size and position of the at least one porous zone relative to the fluid inlet opening defines the evaporation rate of a fluid, arranged such that when a fluid is injected through the fluid inlet opening the fluid flows via hydraulic pressure through the at least one flow channel and then through the respective at least one porous zone. ## Claims ### Claim 1 An arrangement for providing information about a flow rate of a fluid, comprising: a fluid inlet opening; at least one flow channel; and at least one porous zone located above the at least one flow channel, wherein a surface size and position of the at least one porous zone relative to the fluid inlet opening defines an evaporation rate of a fluid, arranged so that when a fluid is injected through the fluid inlet opening the fluid flows via hydraulic pressure through the at least one flow channel and then through the respective at least one porous zone. ### Claim 2 (depends on 1) The arrangement for providing information about a flow rate of a fluid as in claim 1, wherein a distance between at least two adjacent porous zones of the porous zones, Do, provides that the flow rate of the fluid, Qflow, is about equal to an evaporation rate of the fluid, Qevap. ### Claim 3 (depends on 1) The arrangement for providing information about a flow rate of a fluid as in claim 1, comprising a stack of layers, wherein the stack of layers comprises: a top layer defining the at least one porous zone, a middle layer defining the at least one flow channel and a bottom layer serving as a substrate layer, and wherein the fluid inlet opening is defined in the top layer, in the middle layer, or in the bottom layer. ### Claim 4 (depends on 1) The arrangement for providing information about a flow rate of a fluid as in claim 1, wherein the at least one porous zone comprises at least one opening having a hydraulic diameter, do, smaller than a capillary length between the fluid and a gas medium, and, wherein the distance between adjacent porous zones, Do, is larger than the hydraulic diameter of the at least one opening. ### Claim 5 (depends on 4) The arrangement for providing information about a flow rate of a fluid as in claim 4, wherein the hydraulic diameter, do, of the at least one opening is at least 2 μm and at most equal to the capillary length between the fluid and the gas medium. ### Claim 6 (depends on 1) The arrangement for providing information about a flow rate of a fluid as in claim 1, wherein the at least one flow channel has a hydraulic diameter, do, which is at least equal to a surface area of the at least one porous zone. ### Claim 7 (depends on 1) The arrangement for providing information about a flow rate of a fluid as in claim 1, wherein the at least one flow channel has a hydraulic diameter, do, which is smaller than a capillary length between the fluid and a gas medium. ### Claim 8 (depends on 6) The arrangement for providing information about a flow rate of a fluid as in claim 6, wherein the at least one flow channel is coupled to at least one reservoir, wherein dimensions of the at least one reservoir provide that its surface is at least equal to the surface area of the at least one porous zone. ### Claim 9 (depends on 7) The arrangement for providing information about a flow rate of a fluid as in claim 7, wherein the flow channel is coupled to at least one reservoir, the dimensions of the at least one reservoir providing that its surface at least equals the surface area of the at least one porous zone. ### Claim 10 (depends on 3) The arrangement for providing information about a flow rate of a fluid as in claim 3, wherein the top layer has a height, H, less than the hydraulic diameter, do, of the at least one opening. ### Claim 11 (depends on 1) The arrangement for providing information about a flow rate of a fluid as in claim 1, wherein the at least one flow channel has a straight or a meandering shape. ### Claim 12 (depends on 3) The arrangement for providing information about a flow rate of a fluid as in claim 3, wherein the top layer and the middle layer are combined in a single layer, or, wherein the middle layer and the bottom layer are combined in a single layer, or, wherein the top layer, the middle layer and the bottom layer are combined in single layer. ### Claim 13 (depends on 3) The arrangement for providing information about a flow rate of a fluid as in claim 3, wherein each layer is made of a microfabricatable material, and wherein the microfabricatable material comprises: polyethylene terephthalate, silicon, glass, thermoplastic material, or metal. ### Claim 14 (depends on 1) A microfluidic system comprising the arrangement for providing information about a flow rate of a fluid as in claim 1. ### Claim 15 (depends on 14) The microfluidic system as in claim 14, further comprising at least one sensor device. ### Claim 16 (depends on 15) The microfluidic system as in claim 15, wherein the at least one sensor device is configured to detect at least one of: pH, Ca ions, Cl ions, Na ions, ammonia, glucose, or lactate. ### Claim 17 (depends on 1) A method for determining a flow rate of a fluid, the method comprising: providing a fluid in an arrangement for providing information about a flow rate of a fluid as in claim 1 through an inlet opening so that the fluid flows via hydraulic pressure through the at least one flow channel and inside the at least one reservoir and then through the respective at least one porous zone; and determining a flow rate of the fluid by counting a number of porous zones wherein the fluid is observed. ### Claim 18 (depends on 17) The method as in claim 17, wherein the arrangement for providing information about a flow rate of a fluid further comprises at least two electrodes arranged in the at least one flow channel, and wherein counting the number of porous zones comprises measuring an electrical parameter via the at least two electrodes and determining a change in the electrical parameter based on the measurement. ### Claim 19 (depends on 18) The method as in claim 18, wherein the electrical parameter comprises a capacitance or a voltage. ### Claim 20 (depends on 1) The arrangement for providing information about a flow rate of a fluid as in claim 1, wherein the at least one porous zone comprises a plurality of porous zones, wherein the plurality of porous zones is arranged in a regular hexagonal arrangement.