Suzanne,

David Beebe at UIUC (http://mrel.beckman.uiuc.edu/mems/people.html) is a
good person to talk to. He has done a lot of collaborative work in thi sort
of area, and is very innovative.

Southampton University developed some micromachined blades back in the
1990's, for corneal surgery I believe. Graham Ensell
(http://www-icprocessing.ee.surrey.ac.uk/3,6southampton.htm) was my contact
there, who showed me the initial research. I have no idea what happened to
it, but he should remember it.

Alternatively, you may consider using a UV laser, which cuts without
generating heat. Although I have no idea if this would be useful in your
situation, and suspect it could damage the DNA/RNA unless used very
carefully (UV lasers are commonly used in corrective eye surgery). I have
found Exitech to be useful in the past (http://www.exitech.co.uk/).

Sorry this short, but hope it helps.

Danny.

(PS/ suffering from a sticky 's' key; apologies if this has caused more
than the uual number of typos).

At 12:22 14/03/2004 +0100, you wrote:

>-------------------
> > Hello everyone:
> >
> > I am only vaguely familiar with MEMS technology, but I have a
>question
> > about a possible application.  I am a veterinary embryologist and I
>am
> > trying to do "surgery" on embryos that are 100 to 150 microns in
> > diameter (they are about 3 days post fertilization and have
> > approximately 8 cells).  These embryos consist of a clump of very
> > fragile cells surrounded by a very small fluid-filled space
> > approximately 1 to 5 microns wide, and then enclosed in a soft but
>tough
> > shell approximately 10 microns thick.  I need to remove the clump of
> > cells in the middle from their "shell" (the zona pellucida) without
> > ripping them apart or bursting them.  This can be accomplished using
>an
> > enzyme to dissolve the shell, but the enzyme does some damage to the
> > inner cells.  I have also tried using a laser fitted onto the
>objective
> > lens of a microscope to cut the shell, but the cells are so close to
>the
> > shell (touching in places) that I can't avoid overexposure to heat
>from
> > the laser.  I can rip a hole in the shell by holding the embryo with
> > suction on one side applied to a fine glass pipette, while piercing
>the
> > other side with a glass needle; however, when I try to remove the
>embryo
> > by suctioning it out with a glass pipette, the cells get pulled
>apart or
> > ruptured.  I have come to the conclusion that I must cut the
>embryo's
> > shell with a blade (but can't find one small enough) or make a large
> > hole, almost the diameter of the entire embryo, with a sharp
>"biopsy"
> > device while holding the embryo with my suction device (I have tried
> > unsuccessfully to produce a biopsy tool using a glass pipette and a
> > grinding wheel).  I have a set of micromanipulators that allow me to
> > move two tools visualized through an inverted microscope.  The
>problem
> > is that I don't have the tools I need.  I am limited to working with
> > glass rods or tubing and can pull it, cut it, and do some fairly
>crude
> > filing with a grinding wheel.  The embryo must remain in a liquid
>medium
> > during this procedure and is generally placed in a drop of this
>medium
> > in a dish filled with silicone oil.  Is there any way that MEMS
> > technology could be used to solve my problem?
> > Thank you very much for your time.
> > Suzanne Walmsley
> >
> >

--
Danny Banks
danny@dbanks.demon.co.uk
http://www.dbanks.demon.co.uk/