- We tend to degas all aqueous solutions that pass through our devices
under a reasonably strong vacuum (about 5 mmHg) for at least 30
minutes after heating to about 40 degC.  That ensures that they are
pretty thoroughly degassed.

- Degassing PDMS may help, but I doubt it as the vapour from the
solution passing through the device will diffuse into the PDMS anyway
(assuming the parylene hasn't coated the inside channels).

- Have you tried parylene coating before bonding.  Masking the
surfaces to be bonded in the future, parylene coating, removing the
masking layer, UV/O3 treatment and bonding as normal.  This will
affect the parylene layer obviously, but for the brief period of UV/O3
treatment it shouldn't be too bad.

Good luck

Dr Matt Davies
Post-doctoral Research Assistant
Science & Technology Research Institute
University of Hertfordshire
College Lane
HATFIELD        AL10 9AB
UK

e : m.davies@herts.ac.uk
t : +44 (0) 1707 28 61 74
f : +44 (0) 1707 28 1306