Towards a microfluidic dispenser chip for printing of single cells

We present a microfluidic dispenser chip for printing of single-particles or cells onto a substrate. The dispenser chip, fabricated in silicon/glass technology features hydrodynamic flow focusing to transport single particles in a fluid channel and a drop-on-demand dispensing mechanism to eject single particles confined in a free flying droplet of about 200 pl volume. A computer vision-based approach is employed to detect single particles prior to dispensing. We have evaluated the system experimentally by successfully depositing single polystyrene-beads on glass slides with a yield of 92%.