You might be able to look with an IR microscope.

----- Original Message -----
From: "rakesh babu" 
To: "General MEMS discussion" 
Sent: Saturday, October 30, 2004 5:29 PM
Subject: [mems-talk] Leakage test


> folks,
>
>   How can i test whether a liquid trapped inside a
> surface micomachined chamber has leaked through one of
> the etch holes or has evaporated.
>
>  Thanks a lot.
>
> Sincerely
> Rakesh Katragadda