Abstract: A technique is provided for incorporating pneumatic control in centrifugal microfluidics. The technique involves providing a chip controller that has pressurized fluid supply lines for coupling one or more pressurized chambers of the controller with ports of a microfluidic chip. At least part of the chip controller is mounted to a centrifuge for rotation with the chip. A flow control device is provided in each supply line for selectively controlling the pressurized fluid supply, and is electrically controlled. Bubble mixing, on and off-chip valving, and switching are demonstrated.

Abstract: Methods and apparatuses for controlling the size of microbubbles are provided herein. The methods include forming a microbubble in a liquid at an inlet end of a liquid microchannel, the liquid microchannel having an outlet end spaced from the inlet end and a liquid microchannel conduit extending therebetween. As the liquid is propelled along a length of the liquid microchannel, the liquid carry the microbubble, a negative pressure is applied to a first very low pressure microchannel having a first end, a second end spaced from the first end and a first very low pressure microchannel conduit extending between the first end and the second end and having a portion thereof being laterally spaced from and adjacent to a portion of the liquid microchannel conduit. The negative pressure withdraws air from the microbubble in the liquid microchannel to shrink the microbubble as the microbubble travels along the portion of the liquid microchannel conduit.