Microfluidic system including a bubble valve for regulating fluid flow through a microchannel

• US 9,943,847 B2
• Filed: 04/17/2015
• Issued: 04/17/2018
• Est. Priority Date: 04/17/2002
• Status: Expired due to Term

• Current Assignee: Cytonome/St, Llc (Cytonome Inc.)
• Original Assignee: Cytonome/St, Llc (Cytonome Inc.)
• Inventors: Gilbert, John R., Bhm, Sebastian, Deshpande, Manish
• Primary Examiner(s): Menon, Krishnan S
• Assistant Examiner(s): Gerido, Dwan A
• Application Number:
  US14/689,508
• Publication Number:
  US 20160303564A1
• Time in Patent Office: 1,096 Days
• CPC Class Codes: B01L 2200/0605 Metering of fluids
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0858 Side walls
• CPC Class Codes: B01L 2400/06 Valves, specific forms thereof
• CPC Class Codes: B01L 2400/082 Active control of flow resistance, e.g. flow controllers
• CPC Class Codes: B01L 3/502715 characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces
• CPC Class Codes: B01L 3/502738 characterised by integrated valves microvalves F16K99/0001
• CPC Class Codes: B01L 3/502746 characterised by the means for controlling flow resistance, e.g. flow controllers, baffles B01L3/502738 takes precedence
• CPC Class Codes: F16K 2099/0084 Chemistry or biology, e.g. "lab-on-a-chip" technology
• CPC Class Codes: F16K 99/0019 Valves using a microdroplet or microbubble as the valve member
• CPC Class Codes: F16K 99/0061 actuated by an expanding gas or liquid volume

Abstract

A microfluidic system includes a bubble valve for regulating fluid flow through a microchannel. The bubble valve includes a fluid meniscus interfacing the microchannel interior and an actuator for deflecting the membrane into the microchannel interior to regulate fluid flow. The actuator generates a gas bubble in a liquid in the microchannel when a sufficient pressure is generated on the membrane.

Claims

1. A microfluidic device, comprising:

a microchannel having an interior bounded by a side wall, an inlet, a switching region, and a plurality of outlet channels downstream of the switching region, the microchannel formed in a microfluidic chip substrate and configured to accommodate a flow of liquid through the microchannel;

a valve located in the switching region comprising a sealed reservoir, a side passage extending between the reservoir and the interior of the microchannel via an aperture in the side wall, the side passage configured to accommodate a volume of liquid between the interior of the microchannel and the reservoir; and

an actuator integrated in the microfluidic chip, the actuator configured to increase an internal pressure of the reservoir and move at least a portion of the volume of the liquid from the side passage into the microchannel to deflect a portion of the liquid flowing through the microchannel.

2. The microfluidic device of claim 1, wherein the actuator is configured to vary the volume of the reservoir.

3. The microfluidic device of claim 1, wherein actuation of the valve does not block the flow of liquid through the microchannel.

4. The microfluidic device of claim 1, wherein the actuator comprises one of a piezoelectric actuator and an electromagnetic actuator.

5. The microfluidic device of claim 1, wherein the sealed reservoir includes a movable wall, and

wherein the actuator deflects the movable wall to increase the internal pressure of the sealed reservoir.

6. The microfluidic device of claim 1, wherein the sealed reservoir includes a flexible membrane, and

wherein the actuator flexes the flexible membrane to increase the internal pressure of the sealed reservoir.

7. The microfluidic device of claim 1, wherein a stream of particles in a carrier fluid flows through the microchannel, and

wherein, when the actuator increases the internal pressure of the reservoir, a pressure pulse selectively deflects a particle having a predetermined characteristic from the stream of particles.

8. The microfluidic device of claim 1,

wherein increasing the internal pressure of the reservoir generates a pressure pulse within the switching region, and

wherein the pressure pulse travels across the flow direction of the liquid flowing through the microchannel.

9. The microfluidic device of claim 8, further comprising a second sealed reservoir for absorbing the pressure pulse.