Pinched flow fractionation (PFF) for continuous particle separation in a microfluidic device

We propose here a new method for the continuous and accurate sizing of particles using fluid focusing and spreading in a microdevice, named 'pinched flow fractionation (PFF)'. Particles suspended in liquid were continuously introduced into a microchannel having a specific geometry, and were aligned to one sidewall by the other liquid flow without particles, and then separated according to their sizes by the spreading flow profile inside the channel. For the application of this method, we have successfully performed separation of the mixture of micro polystyrene beads. This method is highly advantageous because of its accuracy, applicability and simplicity in operation.