Hi Jian
You might try to use an electronic toothbrush, which is available any
WalMart.
Remove a tip of the toothbrush, and then you will see a metal tip.
Give some vibration by tuning on the toothbrush and touch it just on the
PDMS surface, which you want to remove bubbles. (It will push bubbles toward
outlet of your channels like an ultrasonic pump.)

Good Luck
Sung

=========================================================
Sung Yang
Ph.D. Candidate, Bioengineering
The Pennsylvania State University, University Park
Tel)814-865-6744, 6748
http://biomems.bioe.psu.edu
=========================================================
-----Original Message-----
From: Xu Jason [mailto:xj_world@hotmail.com]
Sent: Thursday, July 01, 2004 9:40 PM
To: mems-talk@memsnet.org
Subject: [mems-talk] How to get rid of the trapped air bubbles in
themicrofluidic chamber?

Hello!
  I am doing some fabrication on the microfluidic chamber by PDMS. When I
try to inject the fluid into the chamber, using syringe pump, I always
found some air bubbles trapped inside the channel.
  Does any of you have the experience of handling this case? I tried to tap
the PDMS to get rid of them, but it worked not well.
  Thank you.

  Sincerely,
  Jian