Hi,
I agree with what Kevin have suggested. Channel outgas technique (COT) is a very
good method to fill channel without generate bubble.
BTW, I'm also curious about the gas permeable membrane.

Huaibin Zhang
---- Original message ----
>Date: Thu, 12 Oct 2006 12:05:14 -0500
>From: Vishwa 
>Subject: [mems-talk] Bubble formation in mircochannels.
>To: mems-talk@memsnet.org
>
>Hi guys,
>I have been facing this problem of bubble formation in my microchannel. The
>dimensions of the channel are 2.5mm across, 5cm long and 60 microns tall.
>The channel has some ridges on the floor and the bubble seem to collect in
>the channel. I try to clear the bubbles by tapping the channel gently from
>the top, but with not much luck. The channel is made of PDMS and I plasma
>bond a glass slide to form one wall. The reynolds number that I work with
>are very very low, on the order of 1. I used fluorescent microspheres in
>water as the solution to pass thru the channel to take some images to
>process them and obtain velocity fields. The water I use is Nonopure water.
>Any help with this will be greatly appreciated.