True that rhodamine will diffused into the pdms. Follow  *"Lab Chip*, 2008,
*8*, 516 - 518". This paper deals with glassy coating of PDMS channels. You
probably want to use this method to avoid diffusion of rhodamine. And I
think for flow characterizations good idea will be to use milk protein or do
PIV measurements.
Best regards
Amit


Dr. Amit Asthana
Senior Research Officer (Microfluidics)
Australian National Fabrication Facility(QLD Node)
Australian Institute of Bioengineering and Nanotechnology
The University of Queensland, Building 75, Room 260,
QLD 4072 Australia
Phone: +61 (0) 7 3346 3421(Office)
 Email: [email protected]
        [email protected]


2009/9/21 

> ---------- Forwarded message ----------
> From: 김태진 
> To: 
> Date: Sun, 20 Sep 2009 09:03:00 +0900
> Subject: [mems-talk] flowing in rhodamine in pdms channel
> Hi all,
>
> I've been trying to flow in fluorescence die (Rhodamine) in a PDMS
> microfluidic channel to do some flow characterizations.
>
> The problem is, the vicinity of the pdms channel became bright as well
> after about 5 minutes.
>
> It almost seemed like that the fluoresent die was diffused into the pdms.
>
> Is there a way to solve this problem?
>
> Thanks!
>
> TJ