Pressure-driven fluidic logic gate

1. A microfluidic chip comprising:

a substrate;

plural layers located on top of each other over the substrate;

a top layer located over the plural layers so that the plural layers are sandwiched between the substrate and the top layer;

a first input port formed into the top layer;

a second input port formed into the top layer;

a first output port formed into a first layer of the plural layers;

a second output port formed into a second layer of the plural layers; and

plural microchannels configured to fluidly connect the first input port and the second input port to each of the first output port and the second output port so that, when a fluid is injected at the first and/or the second input ports, the fluid moves vertically down and then vertically upward through the plural microchannels, to reach the second output port,

wherein the second layer is located over the first layer, and

wherein the first and second output ports are directly exposed to an ambient of the microfluidic chip.

2. The chip of claim 1 , wherein the first and second input ports extend perpendicular to a top surface of the top layer, and the first and second output ports extend parallel to the top surface of the top layer.

3. The chip of claim 2 , the plural microchannels comprising:

a first microchannel extending into the second layer, parallel to the top surface of the top layer, and fluidly connected to the first input port; and

a second microchannel extending into the second layer, parallel to the top surface of the top layer, and fluidly connected to the second input port.

4. The chip of claim 3 , wherein the first and second microchannels intersect in the second layer, at an intersection point.

5. The chip of claim 4 , the plural microchannels further comprising:

a third microchannel that extends through the second layer, perpendicular to the top surface of the top layer, and is fluidly connected, at the intersection point, to the first and second microchannels.

6. The chip of claim 5 , the plural microchannels further comprising:

a fourth microchannel that extends into the first layer, parallel to the top surface of the top layer and the fourth microchannel is fluidly connected to the third microchannel.

7. The chip of claim 6 , wherein the fourth microchannel fluidly communicates with the first output port, through the first vertical microchannel, and with the second output port, through the second vertical microchannel, and the second vertical microchannel is longer than the first vertical microchannel.

8. The chip of claim 3 , wherein the first microchannel is fluidly connected to a third microchannel, which extends perpendicular to the top surface of the top layer, and the second microchannel is fluidly connected to a fourth microchannel, which extends perpendicular to the top surface of the top layer.

9. The chip of claim 8 , the plural microchannels further comprising:

a fifth microchannel extending in the first layer, and fluidly connected to the third microchannel;

a sixth microchannel extending in the first layer, and fluidly connected to the fourth microchannel, wherein the fifth and sixth microchannels intersect at an intersection point; and

a seventh microchannel connected at the intersection point and also fluidly connected to the first output port, through a first vertical microchannel, and to the second output port, through a second vertical microchannel, and the second vertical microchannel is longer than the first vertical microchannel.

10. The chip of claim 1 , wherein the first output port is located on a first side of the plural layers, and the second output port is located on a second side, different from the first side, of the plural layers.

11. The chip of claim 1 , wherein (1) when a fluid is injected at the first or second input port, the fluid reaches only the first output port, but not the second output port, as the fluid lacks enough pressure to move vertically upward along a vertical microchannel of the plural microchannels, which is connected to the second output port, and when (2) the fluid is injected at both the first and second input ports, the fluid reaches both the first and second output ports as the fluid has enough pressure to move vertically upward along the vertical microchannel.