Method and systems for microfluidic logic devices
View Patent ↗A microfluidic device includes an input source characterized by a source pressure and an input channel in fluid communication with the input source. The microfluidic device also includes an output channel and a valve having an open state and a closed state. The valve is disposed between the input channel and the output channel and is characterized by a static pressure. The microfluidic device further includes a control channel coupled to the valve and characterized by a control pressure. In the closed state, the control pressure is greater than atmospheric pressure.
1. A method of fabricating a microfluidic device, the method comprising:
forming a control layer including a control channel and a control layer membrane;
forming a flow layer coupled to the control layer, wherein the flow layer includes a flow channel and a flow layer membrane;
forming a fill layer coupled to the flow layer, wherein the fill layer includes a fill channel and a fill layer membrane;
injecting a fill material into the fill channel;
deflecting a portion of the flow layer membrane to make contact with a portion of the control layer membrane; and
curing the fill material.
2. The method of claim 1 wherein the control channel comprises a chamber underlying the flow channel.
3. The method of claim 1 wherein the control layer membrane and the fill layer membrane comprise PDMS.
4. The method of claim 1 wherein the fill material comprises an acrylate monomer.
5. The method of claim 1 wherein the contact between the portion of the flow layer membrane and the portion of the control layer membrane impedes flow through the flow channel.
6. The method of claim 1 wherein curing the fill material comprises exposing the fill material to at least UV radiation, visible radiation, or thermal energy.
7. The method of claim 1 wherein the microfluidic device comprises a normally closed valve.
8. A microfluidic device comprising:
a substrate;
a control layer coupled to the substrate, wherein the control layer includes a control channel and a control layer membrane;
a flow layer coupled to the control layer, wherein the flow layer includes a flow channel and a flow layer membrane;
a fill layer coupled to the flow layer, wherein the fill layer includes a fill channel and a fill layer membrane, wherein a solid fill material present in the fill layer deflects the flow layer membrane toward the control layer and wherein a portion of the flow layer membrane is in contact with a portion of the control layer membrane.
9. The microfluidic device of claim 8 wherein the contact between the portion of the flow layer membrane and the portion of the control layer membrane defines a contact area.
10. The microfluidic device of claim 9 wherein the control channel comprises a chamber underlying the flow channel.
11. The microfluidic device of claim 9 wherein the control channel has a width and length measured in the plane of the substrate greater than the contact area.
12. The microfluidic device of claim 8 wherein the substrate comprises at least one of a polymer, glass, or silicon.
13. The microfluidic device of claim 8 wherein the control layer membrane and the fill layer membrane comprise PDMS.
14. The microfluidic device of claim 8 wherein the fill layer membrane comprises an elastic or plastic polymer.