Ouch!  A pretty tough application indeed!  I think you will have to relax on
some of your criteria or be a little more specific on what you are trying to
achieve.

For instance
- at those temperatures, Si might even work but AS THE LIQUID; it doesn't
vaporize until above 3200C.  The problem is that below its melting point
your pump might have a hard time pumping when it's a solid.
- diamond could work at those temperatures but a) I am sure that it would be
expensive and difficult to form even simple devices and b) it has the best
thermal conductivity going so the presence of your liquid in channels would
make cooling things worse, not better.  Can you just place your device on a
diamond heat sink?
- if this can't work, you are left with refractory metals like tungsten as
the only solids that can remain solid and be formed (albeit not too easily).
The choice of a suitable cooling fluid that remains in liquid form from room
temp to 3200+ degrees still eludes me, however.

I think the diamond heat sink is much simpler.  It does depend upon what
your ambient atmosphere is, as diamond probably will be oxidized in air at
close to these temperatures and cause you grief.  Hope this helps

Cheers,

Rick Williston
Manager, Nanofabrication
BigBangwidth Inc.
Edmonton, AB

-----Original Message-----
From: [email protected] [mailto:[email protected]]On
Behalf Of Amin Abdul-Fattah
Sent: Thursday, March 07, 2002 1:01 PM
To: [email protected]
Subject: Re: [mems-talk] High temperature


My thesis was a chip that is cooled  using microchannels that passes fluid
in it to bring chip high temp. down and then you might use what is available
of packaging technics (you should connect the microchannels to micro-pump.
Good luck.
Amin Abdul-Fattah
ATE
Ottawa-Canada