Improved Teflon lift-off for droplet microarray generation and single-cell separation on digital microfluidic chips.

Droplet microarrays (DMAs) leveraging wettability differences are instrumental in digital immunoassays, single-cell analysis, and high-throughput screening. This study introduces an enhanced Teflon lift-off process to fabricate hydrophilic-hydrophobic patterns on a digital microfluidic (DMF) chip, thereby integrating DMAs with DMF technology. By employing DMF for droplet manipulation and utilizing wettability differences, the automated generation of high-throughput DMAs was achieved. The volume of the microdroplets ranged from picoliters to nanoliters. For droplets with a diameter of 150 μm, the array density reached up to 1282 cm. We systematically investigated the influence of various DMF parameters on the formation of DMAs and applied this technique to particle distribution, achieving a single-cell isolation rate of approximately 30%. We believe that this method will be a potent tool to enhance the capabilities of DMAs and DMF technology and extend their applicability across more fields.