Journal
LAB ON A CHIP
Volume 13, Issue 13, Pages 2519-2527Publisher
ROYAL SOC CHEMISTRY
DOI: 10.1039/c3lc50075f
Keywords
-
Categories
Funding
- Natural Sciences and Engineering Research Council of Canada
- Russell A. Reynolds Graduate Fellowship in Thermodynamics
- Wallace G. Chalmers Chair of Engineering Design
- NSERC Discovery
- Discovery Accelerator and Strategic Projects program
- Connaught Innovation Award
- Ontario Early Researcher Award
- McGill University, Montreal, QC
- CFI/ORF
Ask authors/readers for more resources
We introduce a miniature gate valve as a readily implementable strategy for actively controlling the flow of liquids on-chip, within a footprint of less than one square millimetre. Bubble gates provide for simple, consistent and scalable control of liquid flow in microchannel networks, are compatible with different bulk microfabrication processes and substrate materials, and require neither electrodes nor moving parts. A bubble gate consists of two microchannel sections: a liquid-filled channel and a gas channel that intercepts the liquid channel to form a T-junction. The open or closed state of a bubble gate is determined by selecting between two distinct gas pressure levels: the lower level corresponds to the open state while the higher level corresponds to the closed'' state. During closure, a gas bubble penetrates from the gas channel into the liquid, flanked by a column of equidistantly spaced micropillars on each side, until the flow of liquid is completely obstructed. We fabricated bubble gates using single-layer soft lithographic and bulk silicon micromachining procedures and evaluated their performance with a combination of theory and experimentation. We assessed the dynamic behaviour during more than 300 open-and-close cycles and report the operating pressure envelope for different bubble gate configurations and for the working fluids: de-ionized water, ethanol and a biological buffer. We obtained excellent agreement between the experimentally determined bubble gate operational envelope and a theoretical prediction based on static wetting behaviour. We report case studies that serve to illustrate the utility of bubble gates for liquid sampling in single and multi-layer microfluidic devices. Scalability of our strategy was demonstrated by simultaneously addressing 128 bubble gates.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available