hi Chris,

   our group has one powder blast machine. An automatic, computer
controlled xy translation stage system is necessary if you really need
uniform and nice blast pattern, and it can be purchased. If you are
only making holes or cuts, then a homemade metal mask and an
installation stage are enough. To prevent clogging, the whole chamber
in which the sample and the blast head are placed should have strong
venting and the bottom of the sample to be drilled through should not
be covered by anything. As the blast power decreases rapidly with the
distance, it normally doesn't cause serious wear to other part of the
chamber. Hope this helps.

 cheers
 jiang ziling


On 4/29/05, Christoph Haas  wrote:
> Dear MEMS community,
> our group is currently setting up powder blasting equipment for
> the micromachining of glass and silicon. My main problem at the
> moment is to set up an xy translation system to scan the blast
> across the target substrate and to do so in a reliable manner.
> If any of you could share their
> experiences about this very practical matter, that would be greatly
> appreciated. Did you use motorised microscope xy stages or some
> other mechanism ? How did you protect the mechanical system
> from clogging and abrasion by stray powder ?
> I've found it difficult to find information about this in the
> literature