Fluid circuit components based upon passive fluid dynamics

A method of controlling fluid flow through a non-wetted fluid circuit comprising at least two connected microchannels, each said microchannel containing a passive fluid flow barrier that creates a fluid pressure barrier, said method comprising:

• advancing fluid in a first microchannel until it is stopped by the fluid engaging a first passive fluid flow barrier;
• advancing fluid in a connected neighboring second microchannel until it reaches a second passive fluid flow barrier;
• and
• overcoming the pressure barrier of one of said first and second passive fluid flow barriers by the fluid engaging the other of said first and second passive fluid flow barriers and with the application of sufficient pressure to the fluid;
• wherein said first passive fluid flow barrier is sufficient to at least temporarily block the flow of fluid in said first microchannel, wherein said second passive fluid flow barrier is sufficient to at least temporarily block the flow of fluid in said second microchannel, wherein one of said first and second passive fluid flow barriers creates a weaker pressure barrier than the other said passive fluid flow barrier, wherein said weaker barrier is overcome first, and wherein at least one of said passive fluid flow barriers is an abrupt microchannel widening.

A method of mixing a first fluid and a second fluid within a non-wetted fluid circuit, said method comprising the steps of

• inserting said first fluid into a main microchannel of said fluid circuit, wherein said first fluid is forced to flow into a first microchannel of said circuit of a known volume by a first abrupt microchannel widening within said main microchannel, and wherein said first microchannel comprises a second abrupt microchannel widening that creates a pressure barrier stronger than said first abrupt microchannel widening, wherein said first fluid is of all amount substantially equal to the volume of said first microchannel, and
• inserting said second fluid into said main microchannel of said fluid circuit, wherein said second fluid is forced past said first abrupt microchannel widening into a second microchannel, and said first microchannel and said second microchannel converge at said second abrupt microchannel widening at which point said first fluid and said second fluid will mix upon continued insertion of said second fluid or application of a force causing said first and second fluids to move;
• wherein said first abrupt microchannel widening is sufficient to at least temporarily block the flow of fluid in said main microchannel, and wherein said second abrupt microchannel widening is sufficient to at least temporarily block the flow of fluid in said first microchannel.

A method of distributing fluid from one channel to multiple wells, chambers or channels of a non-wetted fluid circuit wherein said method comprises the steps of:

• passing the fluid from said one channel to branching channels leading to a first set of wells, chambers or channels, wherein said first set of wells, chambers or channels comprises a first passive fluid flow barrier within each well, chamber or channel that creates a fluid pressure barrier causing fluid to fill said branching channels upstream of said first passive fluid flow barrier prior to moving to a second set of wells, chambers or channels, wherein said second set of wells, chambers or channels comprise a second passive fluid flow barrier within each well, chamber or channel that creates a fluid pressure barrier that is stronger than the fluid pressure barrier created by said first passive fluid flow barriers, wherein the first passive fluid flow barriers comprise said channel opening into said first set of wells, chambers, or channels;
• and
• causing fluid to push past the first passive fluid flow barriers within the first set of wells, chambers or channels and to stop at the second passive fluid flow barriers within the second set of wells, chambers or channels;
• wherein each said first passive fluid flow barrier is sufficient to at least temporarily block the flow of fluid in the corresponding upstream branching channel, and wherein each said second passive fluid flow barrier is sufficient to at least temporarily block the flow of fluid in the corresponding upstream well, chamber or channel.

A microfluidic circuit comprising:

• a. a plurality of microchannels;
• and
• b. a common consolidation clamber;
• wherein each of said plurality of microchannels joins to said consolidation chamber at a junction;
• wherein said consolidation chamber has a cross sectional area substantially greater than the cross sectional area of each said microchannel;
• and wherein a passive fluid flow barrier is formed at the junction of each said microchannel with said consolidation chamber;
• wherein said passive fluid flow barrier formed at the junction of each said microchannel with the consolidation chamber is sufficient to at least temporarily block the flow of fluid in said microchannel.

A method of controlling fluid flow through a non-wetted fluid circuit comprising at least two connected microchannels, each said microchannel containing a passive fluid flow barrier that creates a fluid pressure barrier, said method comprising:

• stopping advancing fluid in a first microchannel with a first passive fluid flow barrier, thereby directing fluid into a connected neighboring second microchannel, wherein said first passive fluid flow barrier comprises an inlet having a radius r1 and an outlet having a radius r2, wherein than r2 is sufficiently larger than r1 to create a passive pressure barrier causing fluid that is advancing through said fluid circuit to stop at said first passive fluid flow barrier;
• and
• overcoming the pressure barrier of the first passive fluid flow barrier by the advancing fluid engaging a second passive fluid flow barrier in the second microchannel, wherein said second passive fluid flow barrier creates a stronger pressure barrier than the first passive fluid flow barrier;
• wherein said first passive fluid flow barrier is sufficient to at least temporarily block the flow of fluid in said first microchannel, and wherein said second passive fluid flow barrier is sufficient to at least temporarily block the flow of fluid in said second microchannel.