Microfluidic pumping

A microfluidic pumping method using:

• (i) a first pulse jet and working fluid in the pulse jet such that the first pulse jet, in response to activation by a set of electrical pulses, moves corresponding pulses of fluid from a first to an second side of the first pulse jet;
• and
• (ii) a chamber with an opening in pressure communication with the first side of the first pulse jet such that activation of the first pulse jet causes a reduced pressure at the opening;
• the method comprising contacting the opening with a fluid and activating the first pulse jet so as to draw a sample fluid through the opening and into the chamber, wherein the opening is in fluid isolation from the first side of the pulse jet, and the sample and working fluids are maintained in isolation.

A microfluidic pumping method using:

• (i) a pulse jet head having first and second pulse jets and a working fluid in the head such that the first pulse jet, in response to activation by a set of electrical pulses, moves corresponding pulses of fluid from a first side of the head to a second side, and the second pulse jet, in response to activation by a set of electrical pulses, moves corresponding pulses of fluid from the second side of the head to the first side;
• and
• (ii) a chamber with an opening in pressure communication with the first side of the head, such that activation of the first pulse jet causes a reduced pressure at the opening and activation of the second pulse jet causes an increased pressure at the opening;
• the method comprising:
• (a) contacting the opening with a sample fluid and activating the first pulse jet so as to draw a sample fluid through the opening and into the chamber;
• and
• (b) activating the second pulse jet so as to discharge sample fluid through the opening.