On Mon, 15 Jun 1998 13:47:07 -0400 (EDT), Han Wen wrote:

>Dear MEMS experts,
>I am in the process of building an X-Y stage for ultrasound
>testing in MRI scanners. I'd appreciate any info. on non-magnetic
>motors, commercial products or otherwise. Thanks much.

New Focus makes an "inchworm" motor which, I believe, is purely
piezoelectric.  There are several patents on use of stacks of piezo
material for traction drives, but I am unaware of commercial products
made thereunder.

-Greg