We generate millions and millions of stabilized bubbles each surrounded by a shell composed of silica nanoparticles in a relatively short amount of time using microfluidics. These bubbles can enhance the detection of oil in oil reservoirs. Sound waves are used to probe water - oil interfaces in oil recovery applications, and since bubbles in fluids vibrate, they are ideal acoustic contrast agents. They can scatter sound waves and act as secondary emitters.
Image from J. C. Wan
We can control bubble size and shell thickness by adjusting the size of the orifices of the capillaries in microfluidic devices, and controlling the flow rates of the fluids. As expected, thicker shell bubbles are more stable than thinner shell bubbles; however, we want the most stable configuration with the thinnest shell possible to produce the most acoustic contrast.
To use stabilized gas bubbles for oil recovery applications it is necessary to flood porous media with very large quantities.
Given the task to generate, in one day, one million- 400 micron diameter- bubbles that are particle stabilized, with nanoparticles, the question is: Can you do it?
The answer is: Yes you can! Using microfluidics!
--> For details, see the Complex Fluids sound bite talk at Yale that I gave in the pdf file below.