Investigation of cold atmospheric plasma treatment in polydimethylsiloxane microfluidic devices with a transmural method.

Here we report a transmural testing that proves cold atmospheric plasma (CAP) can be used to treat the aqueous samples in polydimethylsiloxane (PDMS) microfluidic devices. The reactive species of CAP are found to be able to pass through the PDMS wall and interact with the aqueous medium in the microchannels. The H2O2 concentration, pH value and the bacterial survival number of the treated medium are detected, respectively, to evaluate the feasibility of this method. The relationship between the concentration of H2O2 in the aqueous samples and the thickness of the channel wall is explained by the diffusion mechanism of plasma species in PDMS. The acidification (i.e. decrease of pH value) and sterilization effect of plasma are also observed in the treated samples. This transmural method allows the CAP treatment in PDMS microfluidic devices, which demonstrates that the plasma biomedicine would have potential applications in biomicrofluidics.