Claims
- 1. A method of manipulating a fluid in a microfluidic device, the microfluidic device comprising a substrate having a thickness, at least one microfluidic pathway formed in the substrate, the microfluidic pathway including a passageway, the passageway including an entrance opening having a first minimum dimension, and an exit opening having a second minimum dimension that is greater than the first minimum dimension, the passageway further including a valve seat surface situated between the entrance opening and the exit opening, and a ball element in the passageway between the entrance opening and the exit opening; the method comprising:introducing a fluid into the microfluidic device and in fluid communication with the entrance opening; manipulating a fluid to unseat the ball valve element and flow from the entrance opening toward the exit opening; and causing the ball element to seat against the valve seat surface to at least partially prevent fluid from flowing in a direction from the exit opening toward the entrance opening; wherein manipulating a fluid to unseat the ball element comprises spinning the microfluidic device.
- 2. A method of manipulating a fluid in a microfluidic device, the microfluidic device comprising a substrate having a thickness, at least one microfluidic pathway formed in the substrate, the microfluidic pathway including a passageway, the passageway including an entrance opening having a first minimum dimension, and an exit opening having a second minimum dimension that is greater than the first minimum dimension, the passageway further including a valve seat surface situated between the entrance opening and the exit opening, and a ball element in the passagewuy between the entrance opening and the exit opening; the method comprising:introducing a fluid into the microfluidic device and in fluid communication with the entrance opening; manipulating a fluid to unseat the ball valve element and flow from the entrance opening toward the exit opening; causing the ball element to seat against the valve seat surface to at least partially prevent fluid from flowing in a direction from the exit opening toward the entrance opening; and further comprising heating at least a portion of the pathway downstream of the exit opening.
- 3. A method of manipulating a fluid in a microfluidic device, the microfluidic device comprisng a substrate having a thickness, at least one microfluidic pathway formed in the substrate, the microfluidic pathway including a passageway, the passageway including an entrance opening having a first minimum dimension, and an exit opening having a second minimum dimension that is greater than the first minimum dimension, the passageway further including, a valve seat surface situated between the entrance opening and the exit opening, a ball element in the passageway between the entrance opening and the exit opening; the method comprising:introducing a fluid into the microfluidic device and in fluid communication with the entrance opening; manipulating a fluid to unseat the ball valve element and flow from the entrance opening toward the exit opening; causing the ball element to seat against the valve seat surface to at least partially prevent fluid from flowing in a direction from the exit opening toward the entrance opening; and further comprising subjecting the fluid in the microfluidic device to a thermal cycling process.
- 4. A method of manipulating a fluid in a microfluidic device, comprising:providing a passageway in the microfluidic device that includes a microball valve; causing the microball valve to open by flowing the fluid through the passageway; causing the microball valve to close; wherein the microball valve includes a ball element and a valve seat, and causing the microball to close comprises allowing the force of gravity to move the ball element against the valve seat; and further comprising heating fluid in the microfluidic device causing back pressure to force the ball element in a direction toward the valve seat.
CROSS REFERENCE TO RELATED APPLICATION
The present application claims benefits under 35 U.S.C. §119 and/or §120 from earlier filed U.S. Provisional Patent Applications Nos. 60/398,777, 60/398,778, 60/398,852, and 60/398,946, all filed Jul. 26, 2002. All U.S. patent applications mentioned herein are incorporated herein in their entireties by reference.
US Referenced Citations (9)
Provisional Applications (4)
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Number |
Date |
Country |
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60/398777 |
Jul 2002 |
US |
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60/398778 |
Jul 2002 |
US |
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60/398852 |
Jul 2002 |
US |
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60/398946 |
Jul 2002 |
US |