Methods and apparatus for introducing liquids into microfluidic chambers

Abstract

The present invention is directed to methods and apparatus for removing a gaseous bubble confined in a microvolume of liquid in a chamber. A source of liquid, a barrier region and an exit region are provided in fluid communication with the chamber. The source of liquid has an energy potential as regards movement of the gaseous bubble that is higher than the energy potential of the barrier region, the barrier region has a higher energy potential than the chamber, and the chamber has a higher energy potential than the exit region. The energy potential is reduced within the chamber, the source of liquid, the barrier region, and the exit region by an amount such that the energy within the gaseous bubble is sufficient to displace the gaseous bubble from the chamber through the barrier region and out the exit region and to fill the chamber with the liquid from the source.

Description

BACKGROUND OF THE INVENTION [0001] The present invention relates to microfluidic systems, and more particularly, to methods and apparatus for introducing and distributing fluid in channels of a microfluidic system. More particularly, the invention relates to filling microfluidic systems with liquids in a manner such that no gaseous bubbles are present in the system after filling, because such bubbles, if present, degrade the performance of the system. The microfluidic systems include, for example, microdroplet dispensing devices, microdevices with artificial nanopores, and the like. [0002] In the field of diagnostics and therapeutics, it is often useful to attach species to a surface. One important application is in solid phase chemical synthesis wherein initial derivatization of a substrate surface enables synthesis of polymers such as oligonucleotides and peptides on the substrate itself. Substrate bound oligomer arrays, particularly oligonucleotide arrays, may be used in screenin...

AI Technical Summary

Benefits of technology

[0020] One embodiment of the present invention is a method for removing a gaseous bubble confined in a microvolume of liquid in a chamber. A source of liquid, a barrier region and an exit region are provided in fluid communication with the chamber. The source of liquid has an energy potential as regards movement of the gaseous bubble that is higher than the energy potential of the barrier region, the barrier region has a higher energy potential than the chamber, and the chamber has a higher energy potential than the exit region. The energy potentials of the chamber, the source of liquid, the barrier region, and the exit region are reduced by an amount such that the energy within the gaseous bubble is sufficient to displace the gaseous bubble from the chamber through the barrier region and out the exit region and to fill the chamber with the liquid from the source.

Problems solved by technology

One requirement is that the presence of gaseous bubbles in the system must be minimized, eliminated, or prevented because gaseous bubbles present a problem of hydraulic compliance, which degrades system performance.

Efficient filling of a microfluidic system with liquid can be problematic because gas bubbles such as air bubbles can be trapped in the liquid flow path during introduction of the liquid into the microfluidic system.

Such bubbles are difficult to remove from such systems.

However, the requirement of flushing the buffer solution with the expensive reagent liquid results in some waste of the expensive reagent liquid as well as waste of user time.

The process for establishing a liquid ionic conducting path through an artificially fabricated nanopore often presents difficulties.

Unfortunately, this approach sometimes fails because, when the air pressure is increased, the trapped air bubble may return to its original position, leaving the nanopore blocked.

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