Integrating Miniaturized Turbines into Microfluidic Droplet Generating Systems for Scalable Microgel Production.

Generating microgels is of critical importance in developing granular biomaterials, which have diverse emerging applications in regenerative medicine and tissue engineering. However, producing large volumes of microgels while maintaining a reasonably low population of polydispersity remains a challenge. Here, we introduce the Turbinator, a device that can be added on to the commercially available Shirasu Porous Glass (SPG) microdroplet production system to provide precise control of the local shear stresses around the porous glass droplet production head. In addition to reducing the polydispersity of droplet sizes produced using the SPG, this system allows for continuous production of droplets in inexpensive and massively scalable kerosene oil baths for industrial manufacturing applications. To validate the device, we develop finite element models to understand the local shear stresses applied and characterize the droplets produced under various operating conditions. Finally, we confirmed that this production method supports biological activity via viability and spreading assays of fibroblast cells and invasion assays in a model cancer spheroid system.