Method to micropattern the channels in a Very Large Scale Microfluidic Integrated (VLSMI) chip for high throughput multi-order emulsion production.

Multi-order emulsions have promising uses in drug delivery and the food industry due to their ability to control multiple fluids at the micrometer scale, which relies on creating micropatterns on chips. Current methods of fluidic channel patterning include flowing reagents through the device and using microcapillary-based droplet generators. However, these approaches either have limited spatial resolution or are incompatible with chips holding large numbers of parallelized devices.

To allow precise spatial resolution control, the inventors micro-pattern the wettability of microfluidic channels in a silicon and glass microfluidic chip using a silane coating. They then apply this method to a parallelized microfluidic chip with 2100 double emulsion generators and achieve large-scale multi-order emulsions at high throughput. 

The inventors use lithography for the fluidic channel patterning and a standard silicon and glass microfabrication process. The key is finding the microfabrication process that does not degrade the silane coating. Thus, the surfaces of components are made hydrophobic prior to components bonding. To demonstrate the practical scale-up ability, they fabricate a 2100-channel microfluidic chip with a similar process and additional etching iterations, which generate highly homogeneous double emulsions at high throughput. 

• This strategy is compatible with parallelization designs, which can generate highly homogeneous double emulsions at 10 L/hour, allowing scale-up for commercial manufacturing.
• Strategy is also compatible with the chemical environment of current fabrication processes.
• Both the single microfluidic double emulsion generators and the VLSMI chip can be fabricated with high spatial resolution.
• Ability of mass-production of hollow microcapsules using the VLSMI chip.