Hi, everyone:
    I'm currently working on some PDMS microfluidic strcuture and thinking about
use a thin polystyrene(PS) layer on top of the PDMS to take advantage of PS
surface for bio-application. Has any one done this kinda process before? Is
there any specific thing I need to pay attention to? I have not started doing
this yet. my concerns are the possible poor bonding between PDMS and
polystyrene, and also the possible solvent (I plan to use toluene) diffusion
into the PDMS matrix?  thanks in advance for your input.

Guocheng Shao