# US 9,435,490 B2 · Semipermanently closed microfluidic valve > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,435,490 B2 - Document ID: US9435490B2 - Status: Granted - Kind: B2 - Application number: 13/643,426 - Filed: 2010-04-26 - Published: 2013-06-06 - Granted: 2016-09-06 - Earliest claimed: 2010-04-26 - Assignees: National Research Council of Canada - Applicants: Jean-Christophe Galas; Emmanuel Roy; Teodor Veres - Inventors: Jean-Christophe Galas; Emmanuel Roy; Teodor Veres - Web page: https://patentgrep.com/patent/US9435490B2 ## CPC - F17D 1/00: Pipe-line systems (conveying articles or materials through a pipe- line by means of a fluid carrier B65G51/00, B65G53/00; liquids B67D; special devices for transferring liquids from bulk storage containers into vehicles or boats or vice versa, e.g. loading or unloading vehicles or portable containers B67D7/00; conveying material which has been excavated by a dredger or soil shifter through a pipe-line E02F7/10; sewer pipe-line systems E03F3/00; thermal insulation of pipe-lines F16L59/00; central heating systems F24D) - B01L 3/502738: {characterised by integrated valves (throttle valves in microfluidic sample containers B01L3/502746)} - F16K 99/0026: {Valves using channel deformation} - F16K 99/0059: {actuated by a pilot fluid} - B01L 2400/0661: shape memory polymer valves - Y10T 137/0379: By fluid pressure - Y10T 137/7737: Thermal responsive - F17D: PIPE-LINE SYSTEMS; PIPE-LINES (pumps or compressors F04; fluid dynamics F15D; valves or the like F16K; pipes, laying pipes, supports, joints, branches, repairing, work on the entire line, accessories F16L; steam traps or the like F16T; fluid-pressure electric cables H01B9/06) - B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE - F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)} - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A microfluidic valve operable to semi-permanently close a channel of a microfluidic device defined between a thermoplastic elastomer (TPE) film and a substrate operates employs a surface contact bond between the TPE and a wall of the channel. Thermomechanical release of the valve, tristate functionality, and repeated semi-permanent closure and release are demonstrated. ## Claims ### Claim 1 A microfluidic device comprising: a thermoplastic elastomer (TPE) film having first and second opposite surfaces; a substrate forming a seal with the first surface around a periphery of a channel defined between the substrate and TPE film; and a part of the TPE film defining a membrane having a first side defining part of the channel, and a second side mechanically actuable to close the channel, wherein compositions of the TPE film and the substrate are chosen so that their respective Hildebrandt parameters differ by less than 10 (J/cm3)1/2to permit the membrane to be contact bonded to a channel wall if subjected to a first temperature and pressure regime, to semipermanently retain the channel closed under no persistent force on the second side of the membrane, until re-opened by heating or a thermomechanical stimulus without any layer of adhesive between the TPE film and substrate. ### Claim 2 (depends on 1) The device of claim 1 wherein the compositions of the TPE film and substrate are chosen to permit the membrane to be pressed into the channel to limit flow across the channel by application of a force applied on the second side to temporarily close the channel for the duration of the force without semipermanently closing the channel. ### Claim 3 (depends on 1) The device of claim 1: wherein the channel opposite the membrane is stiffer than the TPE material; wherein the channel is a closed chamber divided by the membrane when the channel is closed; further comprising an actuator for selectively applying pressure on the second side of the membrane to close the channel; further comprising an actuator for selectively applying pressure on the second side of the membrane to close the channel, the actuator including a conduit formed, at least in part, at an interface between the second surface, and another layer of the microfluidic device; wherein the substrate has a through bore opposite the first side of the membrane that is blocked by actuation of the valve; or wherein the compositions of the TPE film and substrate are chosen so that their respective Hildebrandt parameters differ by less than 5 (J/cm3)1/2. ### Claim 4 (depends on 1) The device of claim 1 wherein the composition of the TPE film is a formulation containing: a thermoplastic rubber, a styrenic block polymer, a copolyester, a polyurethane, a polyolefin blend, a polyolefin alloy, a polyamide, an olefin vinyl polymer, an ethylene vinyl alcohol, or a derivative of one or more of the above; a natural rubber, an EVA, a SBR, a SIS, a SBS, an acrylates, or a derivative of one or more of the above a SIS, a SEBS, or a derivative of one or more of the above; or hydrogenated block copolymers such as SIS, SEBS and SEPS or a polyolefin. ### Claim 5 (depends on 1) The device of claim 1 further comprising a pressurized flow control channel separated from the channel only by the membrane. ### Claim 6 (depends on 1) The device of claim 1 wherein the substrate is formed of a rigid thermoplastic. ### Claim 7 (depends on 6) The device of claim 6, wherein the rigid thermoplastic comprises poly(methyl-methacrylate), poly(cyclo-olefin), polycarbonate, or polystyrene. ### Claim 8 (depends on 1) The device of claim 1 wherein the thermoplastic elastomer comprises SIBS. ### Claim 9 (depends on 1) The device of claim 1 wherein the substrate is harder than the TPE film. ### Claim 10 (depends on 1) The device of claim 1 further comprising: two pressurized flow control channels at opposite sides of the channel proximal the valve; a pressurized flow control channel separated from the channel only by the membrane for selectively closing the channel, the membrane being parallel to the substrate; or a pressurized flow control channel separated from the channel only by the membrane for selectively closing the channel, the membrane being perpendicular to the substrate. ### Claim 11 (depends on 1) The device of claim 1 further comprising an actuator for selectively applying pressure on the second side of the membrane to close the channel, the actuator including a conduit formed, at least in part, at an interface between the second surface, and another layer of the microfluidic device. ### Claim 12 : A method for semipermanently closing a channel in a microfluidic device, the channel defined at an interface between a substrate and a TPE film, the TPE film chosen so that their respective Hildebrandt parameters differ by less than 10 (J/cm3)1/2to provide surface bonding to itself and the substrate without any layer of adhesive between the interface, the method comprising: applying pressure to a wall of the TPE film adjacent to the channel to deflect the wall of the TPE film closing the channel, and maintaining this pressure for a prescribed duration, until the surface bond is formed to semipermanently close the channel. ### Claim 13 A microfluidic device comprising: a thermoplastic elastomer (TPE) film having first and second opposite surfaces; a substrate forming a seal with the first surface around a periphery of a channel defined between the substrate and TPE film; a part of the TPE film defining a membrane having a first side defining part of the channel, and a second side mechanically actuable to close the channel; and a pressurized flow control channel for selectively closing the channel, the pressurized flow control channel being separated from the channel only by the membrane, wherein compositions of the TPE film and the substrate are chosen to permit the membrane to be contact bonded to a channel wall if subjected to a first temperature and pressure regime, to semipermanently retain the channel closed under no persistent force on the second side of the membrane, until re-opened by heating or a thermomechanical stimulus. ### Claim 14 (depends on 13) The device of claim 13 wherein the substrate is harder than the TPE film. ### Claim 15 (depends on 13) The device of claim 13 wherein the compositions of the TPE film and substrate are chosen to permit the membrane to be pressed into the channel to limit flow across the channel by application of a force applied on the second side to temporarily close the channel for the duration of the force without semipermanently closing the channel. ### Claim 16 (depends on 13) The device of claim 13 wherein the channel opposite the membrane is stiffer than the TPE material; wherein the channel is a closed chamber divided by the membrane when the channel is closed; further comprising an actuator for selectively applying pressure on the second side of the membrane to close the channel; further comprising an actuator for selectively applying pressure on the second side of the membrane to close the channel, the actuator including a conduit formed, at least in part, at an interface between the second surface, and another layer of the microfluidic device; wherein the substrate has a through bore opposite the first side of the membrane that is blocked by actuation of the valve; wherein the compositions of the TPE film and substrate are chosen so that their respective Hildebrandt parameters differ by less than 10 (J/cm3)1/2; wherein the compositions of the TPE film and substrate are chosen so that their respective Hildebrandt parameters differ by less than 5 (J/cm3)1/2; or further comprising a second pressurized flow control channel at an opposite side of the channel proximal the valve. ### Claim 17 (depends on 13) The device of claim 13 wherein the membrane between the pressurized flow control channel and the channel is: parallel to the substrate or perpendicular to the substrate. ### Claim 18 (depends on 13) The device of claim 13 wherein the substrate is formed of a rigid thermoplastic composed of one of: poly(methyl-methacrylate), poly(cyclo-olefin), polycarbonate, and polystyrene. ### Claim 19 (depends on 13) The device of claim 13 wherein the composition of the TPE film is a formulation containing: a thermoplastic rubber, a styrenic block polymer, a copolyester, a polyurethane, a polyolefin blend, a polyolefin alloy, a polyamide, an olefin vinyl polymer, an ethylene vinyl alcohol, or a derivative of one or more of the above; a natural rubber, an EVA, a SBR, a SIS, a SBS, an acrylates, or a derivative of one or more of the above; a SIS, a SEBS, or a derivative of one or more of the above; or hydrogenated block copolymers such as SIS, SEBS and SEPS or a polyolefin. ### Claim 20 (depends on 13) The device of claim 13 wherein the thermoplastic elastomer comprises oil-free SEBS.