A method, the Stop‑Start method, to eliminate the effect of air bubbles in microchannels utilizing continuous flow is described. In a continuous flow micro-channel, two or more different fluids enter from separate inlets and mix. Introducing a new fluid in microfluidics is usually accompanied by air bubbles. The accumulation and formation of air bubbles is a problem in microfluidics devices as they can be disruptive to the samples flowing into the microfluidic channel and can change the microenvironment. 
Technology Overview
This invention has two different compounds; A and B. First, two syringes will be filled with compound A. The pump will start at a particular volumetric flow rate and fluids enter the channel. There may be some bubbles at the beginning but wait until they pass through the channel and then record the extraordinary optical transmission (EOT) data at each Nanohole Array sensor with the charge-coupled device (CCD) camera. At this point, a switch will use to change the flow from one of the syringes containing fluid A to a syringe containing fluid B from a parallel syringe pump. The parallel pump will be running with the same volumetric flow rate without changing any other characteristics. After initial air bubbles (because of switching syringes) are gone, the data (EOT) will be recorded. In order to compare these two sets of data, the recorded EOTs will be averaged over a certain period of time. The averaged EOT of the reaction compound will be subtracted from that of the pure compound. The EOT difference results are related to the reaction effects. 
- No additional fluid is required to remove the air bubbles from the channels 
- No additional devices are required to remove or trap the air bubbles
- The effect of the injected dead volume is not a concern
- Implementation using the existing continuous flow micro-channels 
- Repeatable data is a major feature of using this method 
- Useful in lab settings as energy output measurement tools.
- The small size, lower compound use, and fast response could move the application into high throughput screening applications.
- License
- Partnering
- Research collaboration
Patent Information:
For Information, Contact:
Mark Saulich
Associate Director of Commercialization
Northeastern University
Masoud Modaresifar
Gregory Kowalski