A Vacuum-Integrated Centrifugal Microfluidic Chip for Density-Based Separation of Microparticles

Here we present a new vacuum-integrated centrifugal microfluidic chip for the density-based separation of microparticles. A sample was loaded in a fluidic channel using the gas permeability feature of polydimethylsiloxane (PDMS) membrane between fluidic and control channels. Vacuum was applied from control channel to drive a density media and then the sample containing microparticles in the dead-end fluidic channel. Afterwards, the chip was disconnected from the vacuum and it was centrifugated. If the sample contains microparticles denser than the density media, the microparticles are sedimented at the end of the microfluidic channel so that these particles can be separated from remaining the lower density particles. With this approach, we separated 1.09 g/mL microparticles with 82,6% efficiency and 99% purity from 1.02 g/mL microparticles. Separated particles in the microfluidic chip can also be inspected under a microscope for further analysis. This simple approach offers high efficient density-based separation of microparticles with close densities.