What do you mean by 'barb diameter'?

What are your *real* specifications?  Flow, power, pressure drop, fluid
material, Cv, temperature range, control range, accuracy, resolution.

Absent those parameters, it seems to me you care only about packaging
connections to your existing system.  (Or, said another way:  why do you
need a *micro* valve?)

In that event, buy the smallest valve/package you can, then make your
own interface.  SMC makes very small valves, as does Clippard and a
number of other companies.  Or, buy raw valves from a company like
Microstaq (if they will sell them to you), and mount in your own
package.  Or, contract with Quake's lab at Stanford to build some PDMS
valves, then mount them yourself into the right package.  (Note that
Stanford cannot make for you devices which will go into commercial
products.)

There used to be a company in Germany (Hoerbiger) which sold small
piezoelectric valves, with very small barb connectors, but I don't know
if you can get them anymore.  The URL below shows pictures, but the
connectors look bigger than you want, so again you'd be forced to build
your own interface.

http://www.directindustry.com/prod/hoerbiger-automatisierungstechnik/int
rinsically-safe-piezoelectric-valve-for-pneumatics-5764-125827.html

Albert K. Henning, PhD
Director of MEMS Technology
NanoInk, Inc.
215 E. Hacienda Avenue
Campbell, CA  95008
408-379-9069  ext 101
ahenning@nanoink.net


-----Original Message-----
From: Jason Milne [mailto:jsmilne@ee.uwa.edu.au]
Sent: Wednesday, July 29, 2009 7:54 PM
To: estesmd@email.uc.edu; 'General MEMS discussion'
Subject: Re: [mems-talk] microvalve

What about an inkjet printer head? I don't have any advice on particular
brands, but I have seen reports of inkjet printer heads being used in
many applications for precise small-volume dosage.

Jason Milne