Hi all,

Does anybody know of another room-temperature material that can be cast on
silicon and removed with ease besides PDMS or RTV?  We are trying to replicate
an etched silicon master with PDMS.  We have tried:

1. RTV on silicon master
2. PDMS on RTV negative

Of course the procedure above does not work because PDMS will not cure well on
hardened RTV (same chemical structure.)  Our next resort was:

1. RTV on silicon master
2. Wax on RTV negative
3. Room-temperature slow-setting epoxy on wax positive
4. PDMS on RTV negative.

This procedure yields average results -- the wax, when solidifying, will have
shrink marks on the mating surface.  These shrink marks eventually get captured
in the PDMS.  Not good.  Any advice would be appreciated.  Thanks!

-John Wu
 Comparative Biomechanics Laboratory
 Tufts University