462538 Inkjet Printed Emulsions and Microparticles for Single-Cell Analysis
We describe an elegant alternative in which electrical signals rather than fluid mechanics are used to acheive extremely regular, periodic generation of droplets. This is acheived using a commercial, off-the-shelf piezoelectric inkjet dispenser suspended above a stirred bath of surfactant-laden oil. Stable and precise droplet generation, at frequencies up to 2 kHz, and with sizes somewhat tunable in the 30-50 micron range, is acheived at the flip of a switch in the "drop-on-demand" mode. Larger droplets (80-100 microns) are produced at 10-20 kHz using the jet breakup mode by applying a constant head pressure to the fluid. Since the aqueous phase (in the inkjet dispenser) and the oil phase are not directly in contact, the two phases can contain incompatible components such as reactive monomers. We demonstrate the use of this system to produce standard water-in-oil emulsions with a variety of hydrocarbon oil and fluorinated oil phases, as well as core-shell microcapsules, and photopolymerized hydrogel microbeads. We demonstrate applications to genetic analysis of single microbial cells. We will discuss practical considerations of the inkjetting setup, and we will discuss unique advantages as well as disadvantages to the inkjetting approach.
See more of this Group/Topical: Food, Pharmaceutical & Bioengineering Division