Spatiotemporally Control of Particle Intervals by On-Chip Vortex Generations

Interval control of particles flowing in a microchannel is a powerful technique for high-throughput cell analyses by regulating the sample even rate for the system sampling rate. However, interval control of large particle over 100 μm, such as cell spheroids and fossil pollen, is still hard task. Here, we present spatiotemporal interval control of large particles for high-throughput analyses by on-chip vortex generations. In this system, we seamlessly integrate four fluidic functions of focusing, concentrating, spacing, and diluting into a microfluidic chip. Remarkably, the system can generate dual vortices on-demand for the spacing function, which play the key role, virtual gate, to periodically stop and pass particles with the generation cycles. We demonstrated this key function using 160-μm beads, and achieved the spatiotemporal control of particle intervals with equivalent to 500 Hz. Our proposed method will open up diverse applications requiring high-throughput analyses of large particles such as cell spheroids and fossil pollens.