Mobile monolithic polymer elements for flow control in microfluidic devices
First Claim
1. A method for making a mobile, monolithic polymer element in a microchannel, comprising;
- a) injecting a monomer mixture dissolved in a solvent into the microchannel, wherein the composition of the monomer mixture is such that the polymer formed by polymerizing the monomer does not bond to the microchannel wall;
b) polymerizing the monomer by application of radiation; and
c) flushing unpolymerized monomer mixture from the microchannel.
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Accused Products
Abstract
A cast-in-place and lithographically shaped mobile, monolithic polymer element for fluid flow control in microfluidic devices and method of manufacture. Microfluid flow control devices, or microvalves that provide for control of fluid or ionic current flow can be made incorporating a cast-in-place, mobile monolithic polymer element, disposed within a microchannel, and driven by fluid pressure (either liquid or gas) against a retaining or sealing surface. The polymer elements are made by the application of lithographic methods to monomer mixtures formulated in such a way that the polymer will not bond to microchannel walls. The polymer elements can seal against pressures greater than 5000 psi, and have a response time on the order of milliseconds. By the use of energetic radiation it is possible to depolymerize selected regions of the polymer element to form shapes that cannot be produced by conventional lithographic patterning and would be impossible to machine.
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Citations
17 Claims
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1. A method for making a mobile, monolithic polymer element in a microchannel, comprising;
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a) injecting a monomer mixture dissolved in a solvent into the microchannel, wherein the composition of the monomer mixture is such that the polymer formed by polymerizing the monomer does not bond to the microchannel wall; b) polymerizing the monomer by application of radiation; and c) flushing unpolymerized monomer mixture from the microchannel. - View Dependent Claims (2, 8)
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3. A method for making a monolithic polymer element in a microchannel such that the polymer element conforms to the configuration of the microchannel and does not bond to the microchannel wall, comprising the steps of:
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preparing a monomer mixture comprising at least; a cross-linking agents selected from the group including ethylene glycol diacrylate, diethylene glycol diacrylate, propylene glycol diacrylate, butanediol diacrylate, neopentyl glycol diacrylate, hexanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetracrylate, trimethylolpropane triacrylate, a nonpolar monomer selected from the group branched or straight chain C1–
C12 alkyl acrylates, fluorinated or methacrylate versions of these monomers, or styrene, anda monomer capable of carrying a charge at a pH of between about 2 and 12 selected from the group including C1–
C12 alkyl or aryl acrylates substituted with sulfonate, phosphate, boronate, carboxylate, amine, or ammonium;adding the monomer mixture to a solvent, comprising at least; one of the group including C1–
C6 alcohols, C4–
C8 ethers, C3–
C6 esters, C1–
C4 esters, C1–
C4 carboxylic acids, methyl sulfoxide, sulfolane, or N-methyl pyrrolidone, dioxane, dioxolane, or acetronitrile, anda polymerization initiator, wherein the monomer/solvent mixture forms a single phase mixture at a temperature below about 40°
C., and wherein the monomer to solvent ratio is between about 90;
10 to 30;
70;loading the mixture into a capillary tube; polymerizing the mixture by exposing at least a potion of the mixture to radiation; and flushing unpolymerized monomer from the microchannel. - View Dependent Claims (4, 5, 6, 7)
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9. A method for making a shaped monolithic polymer element disposed within a microchannel, comprising:
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a) injecting a monomer mixture dissolved in a solvent into the microchannel, wherein the composition of the monomer mixture is such that the polymer formed by polymerizing the monomer does not bond to the microchannel wall; b) polymerizing the monomer by application of radiation; c) flushing unpolymerized monomer mixture from the microchannel; d) exposing the surface of the polymer element to radiation to depolymerize a portion of the surface and thereby shape the polymer element; and flushing the microchannel with a liquid to remove depolymerized material. - View Dependent Claims (10, 11)
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12. A method of making a mobile, monolith polymer element in a microchannel, comprising:
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a) preparing a monomer mixture by mixing together 1,3-butanedioldiacrylate, tetrahydrofurfuryl acrylate, hexyl acrylate, acryloyloxyethyltrimethylammonium methyl sulfate, and a photoinitiator; b) preparing a solvent mixture by mixing together acetonitrile, methoxyethanol, and phosphate buffer; c) mixing together the monomer and solvent mixtures in the ratio of about 60;
40 by volume;d) loading the combined mixture into a microchannel; e) polymerizing the combined mixture by exposure to UV radiation; and
,f) flushing unreacted monomer from the microchannel. - View Dependent Claims (13, 17)
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14. A method of making a mobile monolithic polymer element in a microchannel, comprising:
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a) preparing a monomer/solvent mixture by combining together pentaerythritol triacrylate (PETRA), hyroquinone monomethyl ether, 1-propanol, and an amount of photo-initiator equal to about 0.5% of the weight of the PETRA; b) injecting the monomer/solvent mixture into a microchannel; and c) photopolymerizing the mixture. - View Dependent Claims (15, 16)
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Specification